SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES ? NUMBER 26
Field and Laboratory
Investigations of Meteorites
from Victoria Land, Antarctica
Ursula B. Marvin
and Brian Mason
f EDITORS
f
ii -.
ISSUED
JUN8 1984
SMITHSONIAN PUBLICATIONS
SMITHSONIAN INSTITUTION PRESS
City of Washington
1984
ABSTRACT
Marvin, Ursula B., and Brian Mason, editors. Field and Laboratory Inves-tigations of Meteorites from Victoria Land, Antarctica. Smithsonian Contri-
butions to the Earth Sciences, number 26, 134 pages, frontispiece, 79 figures,11 tables, 1984.?This monograph describes the meteorite collecting activi-
ties in Victoria Land during the 1980-1981 and 1981-1982 field seasons,and the geodetic measurements of ice motion and ablation at the Allan Hills
site. Descriptions and classifications are given for all specimens collectedduring the 1980-1981 season and for most of those collected during the
1981-1982 season. Review articles are included on the petrology and classi-
fication of 145 small meteorites collected in the 1977-1978 season, onAntarctic Type 3 chondrites, and on cosmic-ray-produced nuclides in the
Victoria Land meteorites. The first lunar meteorite is described. Chemicalanalyses of 25 Victoria Land meteorites are published, with a discussion of
Antarctic weathering effects. The Appendix lists all of the Victoria Landmeteorites classified as of June 1983, by numerical order for each locality
and by meteorite class.
OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is
recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: Aerial view
of Ulawun Volcano, New Britain.
Library of Congress Cataloging in Publication Data
Main entry under title:
Field and laboratory investigations of meteorites from Victoria Land, Antarctica.
(Smithsonian contributions to the earth sciences ; no. 26)
Bibliography: p.
1. Meteorites?Antarctic regions. I. Marvin, Ursula B. II. Mason, Brian Harold, 1917-
III. Series.
QE1.S227 no. 26 [QB755.5A] 550s [523.5'1] 83-20087
Contents
Page
EDITOR'S INTRODUCTION, by Ursula B. Marvin and Brian Mason .... 1
THE 1980-1981 FIELD SEASON, by William A. Cassidy 5
THE FIELD SEASON IN VICTORIA LAND, 1981-1982, by R.F. Fudali and
J.W. Schutt 9
ABLATION AND ICE MOVEMENT AT THE ALLAN HILLS MAIN ICEFIELD
BETWEEN 1978 AND 1981, by Ludolf Schultz and John O.
Annexstad 17
DESCRIPTIONS OF STONY METEORITES, by Roberta Score, Carol M.
Schwarz, and Brian Mason 23
DESCRIPTIONS OF IRON METEORITES AND MESOSIDERITES, by Roy S.
Clarke, Jr 49
PETROLOGY AND CLASSIFICATION OF 145 SMALL METEORITES FROM THE
1977 ALLAN HILLS COLLECTION, by Susan G. McKinley and
Klaus Keil 55
CLASSIFICATION, METAMORPHISM, AND BRECCIATION OF TYPE 3 CHON-
DRITES FROM ANTARCTICA, by Edward R.D. Scott 73
A METEORITE FROM THE MOON, by Ursula B. Marvin 95
COSMIC-RAY-PRODUCED NUCLIDES IN VICTORIA LAND METEORITES, by
Kunihiko Nishiizumi 105
BULK CHEMICAL ANALYSES OF ANTARCTIC METEORITES, WITH NOTES
ON WEATHERING EFFECTS ON FEO, FE-METAL, FES, H2O, AND C, by
Eugene Jarosewich Ill
APPENDIX: Tables of Victoria Land Meteorites 115
in
Allan Hills 81005, the first lunar rock to be discovered on the surface of Earth. Photograph
taken before processing at the Curatorial Facility in the NASA Johnson Space Center at
Houston.
Field and Laboratory
Investigations of Meteorites
from Victoria Land, Antarctica
Editors' Introduction
Ursula B. Marvin and Brian Mason
This is the third publication in the Smithson-
ian Contributions to the Earth Sciences series
to review the results of the yearly United States
expeditions to collect meteorites in Victoria
Land, Antarctica. The first two publications
were Catalog of Antarctic Meteorites, 1977-1978
(Marvin and Mason, 1980) and Catalog of Me-
teorites from Victoria Land, Antarctica, 1978-
1980 (Marvin and Mason, 1982). Both publi-
cations were much more than catalogs. They
included descriptions of field and laboratory
investigations and overview articles on the
more interesting types of Antarctic meteorites.
This third publication in the series continues
this practice and so we have dropped the word
"Catalog" from the title.
This issue describes the 1980-1981 and
1981-1982 field seasons in Victoria Land. It
contains chapters outlining the results of the
first geophysical measurements of ice thickness
and the continuing geodetic measurements of
ablation and ice motion in the Allan Hills re-
Ursula B. Marvin, Smithsonian Astrophysical Observatory, 60
Garden Street, Cambridge, Massachusetts 02138. Brian Ma-
son, Department of Mineral Sciences, National Museum of
Natural History, Smithsoniati Institution, Washington, B.C.
20560.
gion. All specimens weighing more than 100
grams, collected in those two seasons, are de-
scribed and classified. In addition, the classifi-
cations of several groups of smaller, pebble-
sized specimens, collected in the 1977-1978
season, have been added to the updated lists
in the Appendices. Appendix Table A lists all
of the Victoria Land meteorites, classified by
May 1983, for each locality by consecutive
numbers; Appendix Table B lists specimens
consecutively by meteorite class; and Appendix
Table C lists the specimens currently believed
to be paired. One chapter reviews new obser-
vations on the rare and relatively primitive
Type 3 chondrites from Antarctica; another
presents the latest measurements of cosmo-
genic nuclides and terrestrial ages of Antarctic
meteorites. A computerized Antarctic Mete-
orite Bibliography is maintained at the Lunar
and Planetary Institute (3303 NASA Road 1,
Houston, Texas 77058) and lists of publica-
tions from it are available on request.
The highlight of the Antarctic collecting
program is the discovery, on the final day of
the 1981-1982 field season, of the first lunar
sample ever to be found on the surface of the
Earth. A brief account is presented of the field
1
SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
occurrence and initial characterization of this
specimen.
The total numbers and classifications of me-
teorite specimens collected in the 1980-1981
and 1981-1982 seasons are listed in Table 1.
After six successive seasons of searches, the
Main Icefield at the Allan Hills region still
yields new specimens yearly, and exploration
has barely begun of the vast reaches of blue
ice in the Middle Western and Far Western
icefields. (For the configuration of these fields
see Marvin, herein, p. 96.) During preparation
of this publication, we received news that re-
connaissance work in the 1982-1983 season
revealed the presence of rich new lodes of
specimens in the area of the Thiel Mountains
(Figure 1). The fruitfulness of the Antarctic
Meteorite Program is thus assured for the fore-
seeable future.
The field explorations and laboratory re-
search are both increasingly international in
TABLE 1.?Numbers of meteoritic specimens collected
in the 1980-1981 and 1981-1982 (in parentheses) sea-
sons.
Class
Chondrites
Carbonaceous
chondrites
Achondrites
Mesosiderites
Irons
Totals
Allan
Hills
30 (355)
0 (4)
1 (10)
0 (2)
1 (2)
32 (373)
Reckling
Peak
60
0
2
4
1
67
Outpost
Nunatak
1
0
0
0
0
1
Totals
91
0
3
4
2
100
Antarctica
KEY;
? Continental Boundary
"? Ice Shelf Border
;=* Major Glaciers
? Meteorite Find
500 km
FIGURE 1.?Map of Antarctic meteorite finds. Four meteorites were discovered before the
beginning of the current program: Adelie Land, 1912; Lazarev, 1961; Thiel Mountains, 1962;
and Neptune Mountains, 1964. Meteorite concentrations were discovered by a United States
party in the Thiel Mountains during the 1982-1983 season.
NUMBER 26
scope. The Japanese program has just com-
pleted its eighth season, working out of Syowa
Base in the regions of the Yamato and Belgica
Mountains. Japanese scientists also spent three
seasons with the United States field parties in
Victoria Land. The United States program,
led by William A. Cassidy of the University of
Pittsburgh, began work in Antarctica in 1976
and has spent seven seasons conducting
searches along the interior flank of the
Transantarctic Range at sites within helicopter
range of McMurdo Station. The United States
field parties have included members from Ja-
pan, West Germany, Denmark, and Switzer-
land, and future teams are expected to include
members from Australia and other countries.
Specimens from the United States collections
have been distributed to at least ninety re-
search laboratories in thirteen countries.
Approximately 7000 specimens, most of
them weighing only a few grams, have been
collected in the past ten years by the Japanese
and United States scientists. These specimens
are important not for their numbers but be-
cause they include new varieties of meteorites,
which have not been found on other conti-
nents, and additional specimens of certain very
rare species. Furthermore, isotopic measure-
ments of terrestrial residence times show that
the Antarctic specimens landed on the Antarc-
tic ice sheet between 10,000 and 700,000 years
ago, with some fall dates clustering between
100,000 and 400,000 years. Most meteorites
collected on other continents fell within the
past 200 years, although a few stones fell as
early as 20,000 years ago. Thus, the Antarctic
ice sheet is furnishing us with a somewhat older
sample of the stony materials that have fol-
lowed Earth-crossing orbits. These results have
aroused the interest of glacial geologists, who
are examining the relationship between mete-
orite concentrations on bare icefields and the
age and flow patterns of the ice in the catch-
ment areas. The Antarctic occurrences have
prompted Canadian and Danish scientists to
explore for similar meteorite concentrations in
the Canadian Arctic and Greenland.
The United States Antarctic Search for Me-
teorites (ANSMET) is governed by an intera-
gency agreement between the National Sci-
ence Foundation, the Smithsonian Institution,
and the National Aeronautics and Space Ad-
ministration. Procedures have been devel-
oped, based loosely on those followed by the
Apollo astronauts, for collecting the specimens
by sterile techniques and keeping them frozen
until they are processed in nitrogen-filled glove
cabinets at the Johnson Space Center in Hous-
ton. Details of the field and laboratory proce-
dures are outlined in the first publication in
this series (Marvin and Mason, 1980). With the
intent of distributing research samples quickly
and widely, all newly classified specimens are
described in the Antarctic Meteorite Newsletter
and mailed, on request, to investigators
throughout the world. Any scientist wishing to
obtain samples may submit a request, describ-
ing the proposed research and the numbers,
weights, and types of samples required, to the
Meteorite Working Group, a committee with
a rotating membership responsible for moni-
toring the program and allocating samples.
Requests for the Antarctic Meteorite Newsletter
or for research samples should be addressed to
the Secretary, Meteorite Working Group, Lu-
nar and Planetary Institute, 3303 NASA Road
1, Houston, Texas 77058.
The Antarctic Meteorite Working Group
meets twice each year, usually in April and
September. Each issue of the newsletter pub-
lishes dates of meetings and deadlines for sam-
ple requests. Sample requests are welcome
from all qualified scientists and are considered
on the basis of their merit regardless of
whether a scientist is funded for meteorite
research. The allocation of Antarctic meteor-
ite samples does not in any way commit a
funding agency to support the proposed re-
search.
Libraries of polished thin sections have been
established in Washington, Houston, and To-
kyo for the use of visitors who wish to make
microscopic examinations. The library thin
sections are not available for loan. To obtain
SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
meteorite samples from the Japanese collec-
tions or to use the thin section library in To-
kyo, contact T. Nagata, Director, or K. Yanai,
Curator, at the National Institute of Polar
Research, 9-10 Kaga 1-chome, Itabashi-ku,
Tokyo 173, Japan. To use the thin section
library at the Johnson Space Center in Hous-
ton, contact the Secretary of the Meteorite
Working Group at the address given above.
To make arrangements for using the library at
the National Museum of Natural History,
Smithsonian Institution, Washington, D.C.
20560, contact Brian Mason, Curator.
Literature Cited
Marvin, Ursula B., and Brian Mason, editors
1980. Catalog of Antarctic Meteorites, 1977-1978.
Smithsonian Contributions to the Earth Sciences, 23:
50 pages.
Marvin, Ursula B., and Brian Mason, editors
1982. Catalog of Meteorites from Victoria Land,
Antarctica, 1978-1980. Smithsonian Contribu-
tions to the Earth Sciences, 24: 97 pages.
The 1980-1981 Field Season
William A. Cassidy
The 1980-1981 field season was the fifth
enterprise supported by the National Science
Foundation in as many years. Beforehand, we
knew that in addition to the Main Icefield
(76?42'S, 159?20'E) at Allan Hills, where the
existence of a large meteorite concentration
had been proved, lesser concentrations of me-
teorites could be found at the Near Western
Icefield (76?40'S, 158?49'E), Reckling Mo-
raine (76?08'S, 158?47'E), and Elephant Mo-
raine (76?14'S, 157?11/E). We were eager to
investigate new sites in the hope of locating
additional concentrations that could be ex-
ploited during future field seasons. We there-
fore devoted as much time as possible to recon-
naissance and as little time collecting meteor-
ites at known sites as was necessary to assure a
successful season.
After collecting 32 specimens at Allan Hills
we traversed to Reckling Moraine, where we
recovered 67 specimens. Reckling Moraine
(Figure 2) is an extensive ice-cored detrital
rock deposit with no outcropping source in the
upstream direction. The source of the moraine
rocks therefore may be an elevated segment of
an underlying east-west ridge whose surface
expression on the ice is a step feature associ-
ated with the Reckling Moraine Icefield. This
icefield averages 3-5 km in width and extends
about 100 km in the east-west direction. Ele-
phant Moraine is located about 50 km to the
William A. Cassidy, Department Geology and Planetary Sci-
ence, University of Pittsburgh, Pittsburgh, Pennsylvania
15260.
west, along the same icefield. It may be that
the sites of highest meteorite concentration
along this icefield are at or near these mo-
raines. These, in turn, could result from a
more sluggish flow of ice over the subsurface
barriers that produce these moraines. As we
have seen at Allan Hills and Yamato Moun-
tains, meteorite concentrations tend to occur
at sites where ice flow is sluggish or stagnant.
Approaching the icefield at Reckling Mo-
raine from the south, we had to lower our
supply-laden Nansen sledges down the 15?-
20? face of the step feature by using snowmo-
biles in tandem: one at the rear, braking to
stabilize the sledge, and one in front, pulling
gently to keep its heading true. As in our
previous visit, we followed the same route
across the step feature as the one first used by
the Philip Kyle party in December 1978. At
the bottom of the step feature we were on the
main part of the Reckling Icefield.
Prevailing wind direction is generally south-
westerly across the narrow dimension of the
icefield. Most of the 67 specimens we re-
covered were small (20-100 g) individuals or
fragments found near the firn-ice boundary
along the northern edge of the icefield. Pre-
sumably these are small enough to have been
blown across the ice surface by strong winds,
then trapped against snow and firn at the
northern edge of the ice.
While at Reckling Moraine we received an
air-drop of eight drums of snowmobile fuel to
enable us to extend our traverse to points
farther to the north: these included ice expo-
SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 2.?Oblique photo looking westward at Reckling Moraine from a point above Reckling
Peak. Smooth gray areas are patches of exposed ice. Lighter gray areas are snow. In some
places the snow surface appears rough due to the presence of snow dunes (sastrugi). Near the
center of the photo is a sinuous feature having the gray of exposed ice but with a rougher
surface. This is Reckling Moraine. That part of the exposed ice that looks like a line of low
hills and which tends to mimic the irregular boundary of the moraine is the step feature
referred to in the text.
sures associated with Griffin Nunatak (Figure
3), Brimstone Peak, Tent Rock, and Sheppard
Rocks. We hoped to augment the minimum
collection we had made so far with additional
recoveries from new concentration areas, but
in this we were to be disappointed. A single
small specimen was found at Outpost Nunatak,
an outlier of Griffin Nunatak, but none were
found at the other sites; thus it was well illus-
trated that not all fields of exposed ice can be
expected to produce meteorite concentrations.
At these barren localities we were relatively
close to an area of fast-moving ice at the head
of the David Glacier. In addition, the icefields
are located downstream of the outcrops; there-
fore, the ice probably is migrating toward the
head of the David Glacier unimpeded by inter-
vening barriers. In these areas, too, wind di-
rection was such that snow was piled against
the upstream sides of the barriers, so that ice
ablation was not occurring in the stagnant flow
regimes where meteorite stranding would be
favored. The net result of our reconnaissance
efforts during the 1980-1981 field season was
a greater understanding of the conditions un-
der which meteorite surface accumulations oc-
cur, and do not occur.
In other activities during the 1980-1981
season, we obtained new measurements of
ablation rates at our Allan Hills triangulation
network (Cassidy and Annexstad, 1981), and
one member of our party devoted considerable
time to foot searches for meteorites in Taylor
Valley, with negative results. This is of interest
because certain surfaces in the Dry Valleys,
(77?-78?S, 160?-163?E) are expected to be
rather ancient and one would not be surprised
to find accumulations of meteorites that had
NUMBER 26
tmWk
FIGURE 3.?Camp at Griffin Nunatak, 30 km north of Reckling Peak. Part of the nunatak
forms the rock cliff in the background.
fallen on them and been preserved in the dry
environment. Mechancial erosion, however,
may be more efficient in the Dry Valleys than
on the icefields farther inland. Alternatively,
TABLE 2.?The 1980-1981 collection.
Chondrites
Carbonaceous
chondrites
Achondrites
Mesosiderites
Irons
Totals
Allan
Hills
30
0
1
0
1
32
Reckling
Peak
60
0
2
4
1
67
Outpost
Nunatak
1
0
0
0
0
1
the Dry Valley surfaces may be less ancient
than has been believed.
The classification of meteorites recovered
during the 1980-1981 season is given in Table
2.
Expedition members were W.A. Cassidy,
J.O. Annexstad, J. Schutt, L.A. Rancitelli, L.
Schultz, H. McSween, and J. Danielson. This
work was supported by NSF/DPP 78-21104
and is Departmental Contribution 572.
Literature Cited
Annexstad, J.O. and W.A. Cassidy
1981. Antarctic Search for Meteorites, 1980-1981.
Antarctic Journal of the United States, 16(5):61-
62.
The Field Season in Victoria Land, 1981-1982
R.F. Fudali andJ.W. Schutt
The 1981-1982 field season in Victoria
Land was, by any measure, highly successful.
Major accomplishments included a second re-
survey of the established triangulation net-
work, the recovery of 378 meteorite speci-
mens, and a gravity survey to model the ice-
bedrock interface, all at the Allan Hills, South
Victoria Land (76?45'S, 159?40'E). Further,
advantage was taken of logistic support pro-
vided by a season-long field camp in North
Victoria Land (72? 12'S, 163?50'E) to conduct
reconnaissance meteorite searches in this new
area and to examine a possible small meteorite
crater at Littel Rocks (7l?23/S, 162?0/E).
The team was led again by William Cassidy,
University of Pittsburgh. Other participants
were John Annexstad, NASA Johnson Space
Center; Ghislaine Crozaz, Washington Univer-
sity at St. Louis; Ursula Marvin, Smithsonian
Astrophysical Observatory; Ludolf Schultz,
Max Planck Institute for Chemistry; and the
authors.
Annexstad and Schultz spent the period 15
November to 13 December determining hori-
zontal and vertical displacements of their trian-
gulation stations for the second time since their
emplacement. They also continued their yearly
measurements of ice ablation rates (see Schultz
and Annexstad, herein, or Cassidy and An-
nexstad, 1981). These tasks were accomplished
R.F. Fudali, Department of Mineral Sciences, National Mu-
seum of Natural History, Smithsonian Institution, Washington,
D.C. 20560. I. W. Schutt, Department of Geology and Plane-
tary Sciences, University of Pittsburgh, Pittsburgh, PA 15260.
despite long stretches of extremely bad
weather, which, however, did prevent them
from extending the network further west.
The authors spent 24 November to 15 De-
cember at the North Victoria Land (NVL)
camp, 600 km north of McMurdo Station near
the head of the Canham Glacier. Here the
camp scientists were supported by a number
of snowmobiles and three HU-1N helicopters.
Air photos of the region, on file at USGS
Headquarters in Reston, Virginia, were used
to delineate a number of promising bare ice
areas within helicopter range of the NVL
camp. The crater at Littel Rocks was also
found during this archival search.
The reconnaissance in NVL was largely by
helicopter, but it was necessary to make rather
frequent ground checks because of the unan-
ticipated litter of terrestrial rubble on many of
the bare ice surfaces. Bare ice patches at the
Lonely One Nunataks, Reniere Rocks, Emlen
Peaks, Outback Nunataks, Johannsen Nuna-
tak, Frontier Mountan, Onlooker Nunatak,
and Monument Nunatak were examined. Ice-
fields in the southern and western regions of
the Daniels range were also overflown and a
snowmobile traverse to the ice patches near
the Gallipoli Heights was undertaken. No me-
teorites were found during any of these
searches; because of the terrestrial rocks litter-
ing many of these surfaces we cannot categor-
ically say there are no meteorites present.
However, it is clear that there can be no large
meteorite concentrations such as those at the
Allan Hills and the Yamato Mountains. Most
9
10 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
of the meteorites found to date in Antarctica
have been on ablation surfaces upstream of
rock barriers to ice flow. In the areas accessible
by helicopter from the NVL camp there ap-
pear to be no such upstream icefields. Rather
there are a number of fast-moving glacial sys-
tems without extensive areas of stagnant ice.
The terrestrial rocks littering many of these
bare ice surfaces in the vicinity of outcropping
bedrock presumably indicates these surfaces
are moving away from, rather than toward,
the potential rock barriers. In general then,
such rock litter may prove to be a strong
contraindication of meteorite concentrations,
and future reconnaissance in new areas should
be conducted with this in mind. Unfortunately,
the size range of the rock litter is far too small
to be detected on air photos. Whether or not
there are other subtle diagnostic features on
the air photos that would permit us to distin-
guish stagnant from moving icefields is a ques-
tion we have not yet answered. The utility of
being able to make such distinctions is obvious;
an important step in addressing the question is
searching apparently promising icefields and
finding no meteorite concentrations. So our
negative findings at NVL may well prove more
useful, in the long run, than if we had found
meteorites there.
One day was spent examining the circular
"crater" at Littel Rocks. The depression is
about 125 m in diameter and has a terrace
partially incised inside its bowl, about 5 m
above the floor. The depression would be a
closed basin of deposition for water, but it has
clearly been overidden one or more times in
the past by ice. We surmise that the terrace
represents the former water level of a shallow
lake and was sculpted by moving ice when the
lake was frozen. There are other such shallow
lakes in the area although none are so circular
as this example. In any case we found no
evidence of a meteoritic origin?in fact quite
the contrary. Littel Rocks is composed of a
dolerite intrusion characterized by a very
strong, narrowly spaced, vertical joint system.
This vertical jointing can be observed, undis-
turbed, in the floor of the depression; i.e.,
there is no rubble zone beneath the present
floor and the depression is much too shallow
(10-15 m) to contemplate the removal of such
a rubble zone by eroding ice. We therefore
conclude that the depression is not an impact
crater and is most likely the result of glacial
activity.
The amenities of a season-long Antarctic
field camp, such as the NVL establishment,
have been described in some detail by Marvin
(1982) and will not be repeated herein. Suffice
it to say that one of us (RFF) was quite pre-
pared to not find meteorites throughout the
balance of the field season at NVL until ad-
vised that this was not a permissible option.
In contrast to the areas searched in NVL,
meteorites were still readily found on the bare
ice patches west of the Allan Hills. A party
consisting of Cassidy, Crozaz, Marvin, and the
authors spent 33 days in this area (22 Decem-
ber 1981 through 23 January 1982).
The Allan Hills icefields comprise five sepa-
rate bare ice areas (Figure 4). The Main Ice-
field extends NNW from Peak 2330 for nearly
22 km and contains roughly 75 km2 of blue
ice. The Near Western Icefield, 18 km west of
Peak 2330, contains about 14 km2 of blue ice.
The Middle Western Icefield, 31 km WSW of
Peak 2330, contains about 30 km2 of blue ice.
The Far Western Icefield (not shown on Fig-
ure 4) is a vast area of blue ice, over 40 km
long and 2-8 km wide, with an area in excess
of 100 km2. Its southeastern end is some 70
km WSW of Peak 2330. Because of poor
weather and insufficient time, a planned recon-
naissance of the Far Western Field during the
1981-1982 season was not attempted. The
Battlements Icefield, slightly smaller than Mid-
dle Western Field, had not been examined
previously, primarily because of the very dif-
ficult terrain immediately south of Battlements
Nunatak. This season our party reached the
nunatak and found a passage through it to the
icefield. A cursory examination of the ice sur-
face revealed it to be littered with terrestrial
rocks. No attempt was made to search for
NUMBER 26 11
0 5 10
i i i km
N
Main
Near Western Icefield
??-..:?.?.?; ..'.l'%
Middle Western Icefield
Battlements Nunatak7
Icefield^
Peak 2330
Carapace N unatak
FIGURE 4.?Meteorite collecting areas west of the Allan Hills. Dots outline bare icefields.
Stippled areas were searched by a reconnaissance mode. Striped areas were searched system-
atically during the 1981-1982 field season.
meteorites. Based on our observations at NVL
we predict that there is no concentration of
meteorites on this icefield. However, it should
certainly be searched at a future date to test
the predictive power of our NVL experience.
The Main Icefield, searched the longest and
most thoroughly, yielded 286 meteorites and
meteorite fragments during the 1981-1982
season, bringing the recovered total from this
field to 1020. There are at least two reasons
why the yield from this field remained high
this season despite five previous search efforts.
First these so-called "blue or bare ice" patches
are not really bare. At any given time there
will be a 30-50% snow cover largely in the
form of low, N-S trending linear drifts termed
sastrugi (Figure 6). As this snow cover shifts
from year to year, new, hitherto unobservable
ice surfaces, and the meteorites contained
thereon, become exposed. Second, and per-
haps more importantly, for the first time sys-
tematic, steel-cleated snowmobile sweeps were
12 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
J
FIGURE 5.?Helicopter delivering snowmobiles to the Allan
Hills camp.
FIGURE 6.?Typical surface of the Main Icefield illustrating
partial snow cover.
FIGURE 7.?Snowmobile team preparing to spread out
abreast to a 30-50 meter spacing.
conducted over the areas of highest potential
(meteorites have been found over nearly the
entire Main Icefield but some areas show much
higher concentrations than others, nearly bar-
ren areas). Typically, once a promising area
was found, 4-5 snowmobiles (Figure 7) were
aligned abreast, 30-50 m apart, and a disci-
plined sweep was made in a chosen direction.
At the end of a sweep the line pivoted about
the "outside" searcher and reversed its direc-
tion. The "outside" searcher then became the
"inside" searcher following his/her track back
to its beginning while the others traversed new
ground. This sequence was repeated until the
area of interest was completely swept, with a
high probability of recovering almost all the
exposed meteorites. Meteorites as small as a
few millimeters in maximum dimension were
recovered by this technique.
Two and a half days were spent systemati-
cally searching the Near Western Icefield. Sev-
enty-eight specimens representing a maximum
of 24 individuals were recovered. At least 52
weathered fragments appear to be from a sin-
gle individual and are similar to 30 fragments
recovered in previous years from the same
area. This icefield yielded the largest meteorite
recovered in the 1981-1982 season: the 18 kg
hexahedrite described by Roy Clarke (p. 50).
A two-man, one-day reconnaissance at the
Middle Western Icefield returned 14 frag-
ments representing 11 individuals. Several
other meteorites were found but not collected
because of poor weather and insufficient time.
These were flagged for collection next season.
From the short times spent at the Near and
Middle Western icefields it is clear that a large
number of meteorites remain on these surfaces
for future collecting. Under the reasonable
assumption that we are merely observing the
exposed portions of a single concentration sys-
tem, there must be a very much larger number
of meteorites beneath the thin snow cover
separating the three icefields (Main, Near, and
Middle). Whether or not the meteorite concen-
tration extends to the Far Western Icefields
NUMBER 26 13
should be known after the 1982-1983 season.
In summary, a total of 314 field sample
numbers were issued for the 378 meteorite
individuals and fragments recovered from the
Allan Hills icefields during the 1981-1982
season; the discrepancy between the two num-
bers reflects the obvious pairing of fragments
from the same meteorites.
Prior to the 1981-1982 season little effort
was made to accurately map the sites of mete-
orites found on the Allan Hills icefields. This
past season we surveyed the positions of the
recovered meteorites so that detailed location
maps could be produced. The 24 station trian-
gulation network was used as a base for deter-
mining meteorite positions on the Main Ice-
field. The surveying instruments and tech-
niques were rather crude but, we believe, more
than adequate for the possible uses of such
locality data. Where the triangulation network
was not a practical reference, an initial point
was established by a three-point resection from
prominent landmarks, plotted on the U.S.G.S.
Convoy Range 1:250,000 scale quadrangle map.
A detailed meteorite location map for the
Main Icefield has been produced and has al-
ready proven useful for examining the possi-
bility of paired falls of similar meteorites (Mar-
vin, personal communication).
Together with their terrestrial ages, a knowl-
edge of the distribution of the larger meteor-
ites on the icefields may help determine mete-
orite accumulation rates, ice dynamics, and
perhaps other factors bearing on meteorite
concentration mechanisms. The locations of
meteorites smaller than about 4 cm (maximum
dimension) in size are only useful for accu-
rately locating the downwind edge of an ice-
field. The ever-present katabatic winds are
capable of skittering these small meteorites
across the ice until they lodge in the snow
bordering the bare ice areas.
As part of the on-going effort to delineate
the meteorite concentration mechanisms at the
Allan Hills, a large number of ice samples were
collected at regular intervals along two east-
west traverses across the Main Icefield, and the
sample positions flagged for future reference.
These ice samples were sent directly to Ohio
State University for petrographic examination
by Ian Whillans, a glaciologist with substantial
experience in Antarctica. Dr. Whillans spent
the final ten days with our party at the Allan
Hills and was most impressed with what he
tentatively concluded was an exposed vertical
ice section, now running horizontally east-
west, that could cover a 600,000 year period.
Two large blocks of ice were also collected for
radioactive dating and gas content determina-
tions. One of these blocks was excavated from
directly beneath the find site of one of the
largest chondrites (18 cm, maximum dimen-
sion, field number 1556) that we had collected.
Finally, gravity measurements were made at
all 24 stations of the previously established
triangulation network across the Main Icefield
(Figures 8 and 9). Eight additional stations
were occupied on bedrock, from the northern-
most tip of the Allan Hills south to Carapace
Nunatak, to help define any north-south re-
gional gravity trend that might be present.
Calibration of the gravity data was provided
by a single, direct ice-thickness measurement
at station 3 of the network, obtained previously
by radio-echo sounding (Kovacs, 1980). With
this calibration the gravity values could be used
to compute ice thicknesses at all the other
stations and so model the shape of the ice/
bedrock interface beneath the station network.
A detailed description of this survey may be
found in the 1982 review issue of the Antarctic
Journal (vol. 16, no. 5). Only the conclusions
are summarized herein.
The calculated east-west profiles are shown
in Figure 10. The principal possible error
source in constructing these profiles is our
ignorance of the east-west regional gravity
trend, if any. However, the corrections for any
such trend would only rotate the entire profiles
up or down about the easternmost points with-
out changing their relative shapes. Thus any
conclusions based on a comparison of relative
bedrock slopes will be valid irrespective of any
east-west correction.
14 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
SNOW COVERED
159? E
17 ^\ 15 1219
-76C45'S
KILOMETERS
ANTARCTIC METEORITE DISCOVERY AREA
FIGURE 8.?The triangulation network across the Main Icefield at Allan Hills.
NUMBER 26 15
FIGURE 9.?Gravity team at work.
A firm conclusion that can therefore be
reached is that, if the (exposed) Allan Hills act
as a barrier to ice movement, then surely the
barrier should begin much further west where
comparable bedrock slopes are present. This
conclusion is consistent with our 1982 recon-
naisance of the Middle Western Icefield, which
revealed meteorite concentrations 35 km west
of the Allan Hills. It is, however, not consistent
with the latest reported triangulation network
remeasurements (Schultz and Annexstad, this
issue), which indicate a zero horizontal flow
rate, 5 km west of the Allan Hills, but an
eastward flow of ~ 1 meter/year for the ice 13
km west of the exposed barrier. Although we
have no certain explanation for the discrep-
ancy between the two data sets, we do note
that the more precise instruments used in the
1981 resurvey lowered the maximum reported
horizontal flow rate from 2.5 to 1 meter/year.
At the same time, the earlier imprecision
causes the retention of high probable errors,
which remain on the order of the reported
5KM
- 1000
FIGURE 10.?Gravity-deduced bedrock configurations beneath the triangulation network.
16 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
rates themselves. The network was surveyed
again during the 1982-1983 season and it will
be interesting to see whether this data substan-
tiates the latest reported (1981) rates.
Literature Cited
Cassidy, W.A., and J.O. Annexstad
1981. Antarctic Search for Meteorites, 1980-1981.
Antarctic Journal of the United States, 16(5):61-
62.
Kovacs, A.
1980. Radio-Echo Sounding in the Allan Hills, Ant-
arctica, in Support of the Meteorite Field Pro-
gram. Special Report 80-23, U.S. Army Corps of
Engineers, Cold Regions Research and Engi-
neering Laboratory, Hanover, New Hamp-
shire.
Marvin, U.B.
1982. The Field Season in Victoria Land, 1978-
1979. In U.B. Marvin and B. Mason, editors.
Catalog of Meteorites from Victoria Land, Ant-
arctica, 1978-1980. Smithsonian Contributions to
the Earth Sciences, 24:3-8
Ablation and Ice Movement at
the Allan Hills Main Icefield
between 1978 and 1981
Ludolf Schultz and John O. Annexstad
Introduction
The total number of meteorites found in
Antarctica through the southern summer of
1981-1982 exceeds 6000. More than 1000
meteorites have been collected on the icefields
near the Allan Hills in South Victoria Land.
The United States Antarctic Search for Mete-
orites (ANSMET), led by W.A. Cassidy, has
concentrated in this area not only to search for
meteorites but also to study the general phe-
nomenon of meteorite concentrations on blue
icefields in the Antarctic. For a general intro-
duction one is referred to Cassidy et al. (1977),
Marvin (1981), Schultz (1982), and Cassidy
and Rancitelli (1982).
Two factors contribute to the high meteorite
concentrations on the surface of some icefields.
(1) Small meteorites with weights of a few
grams can be detected on bare icefields while
in other areas of the Earth similar stones are
hidden among terrestrial rocks or vegetation.
(2) Weathering is less severe under Antarctic
conditions. Without liquid water meteorites
are preserved for longer periods of time than
in temperate climates. Furthermore, paired
meteorite falls contribute to the larger number
of meteorite finds. Detailed studies of all me-
Ludolf Schultz, Max-Planck-Institut fur Chemie, D-65 Mainz,
West Germany. John O. Annexstad, NASA Johnson Space
Center, Houston, Texas, 77058.
teorite fragments are necessary to recombine
multiple falls. Seventy-five meteorites have
been tentatively identified as belonging to 13
individual falls in the Allan Hills region (Mar-
vin and Mason, 1982). Even after taking into
account all of these effects, a mechanism that
concentrates meteorites fallen on large areas is
still necessary to explain the high concentra-
tions on some icefields in Antarctica.
Several hypotheses have been proposed to
explain these meteorite concentrations (Cas-
sidy et al., 1977; Nagata, 1978; Whillans,
1982). Generally, the process of meteorite con-
centration is based on the assumption that
meteorites entrapped in the ice in the interior
of the continent will emerge on the surface of
stagnant icefields close to coastal mountain
chains where the outward flow of ice is
blocked. All hypotheses need three basic pa-
rameters to obtain quantitative results: (1) ter-
restrial ages of meteorites; (2) ablation rates of
the ice in regions with high meteorite concen-
trations; and (3) direction and velocity of the
ice movement into these regions.
Terrestrial ages have been determined using
radioactive cosmogenic nuclides like 14C, 26A1,
36C1, and 81Kr. The results show that a large
number of Antarctic meteorites have rather
high terrestrial ages with values up to 700,000
years (Fireman et al., 1979; Evans et al., 1982;
Nishiizumi et al., 1983; Freundel and Schultz,
in prep.).
17
18 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
To obtain information on ablation and ice
movement, a triangular network of 20 stations
was established at the Allan Hills icefield in
1978 (Nishio and Annexstad, 1979). Figure 11
shows a map of the Allan Hills area with the
triangulation chain, which is based in bedrock
and extends more than 13 km westward, cross-
ing the icefield with high meteorite concentra-
tions. Figure 12 shows the Allan Hills with
station 1 at the lower left corner and Figure
13 is a view from a helicopter in a southwes-
terly direction with the 1981 campsite. After
the first measurement in 1978, the chain was
resurveyed in 1979 (Nishio and Annexstad,
1980; Annexstad, 1982). We report here a
summary of another redetermination of the
properties of the network in November and
December 1981.
The method of the survey was essentially the
same as in previous years. However, the instru-
ments used were more modern: a Wild theo-
dolite with 400g (360?) reading was used for
the measurement of horizontal and vertical
angles, and the slope distances between adja-
cent stations were directly observed with a
Wild Distomat DI4L (Figure 14). Due to ad-
verse weather conditions in November 1981,
in most cases only one side of each of the 18
(?) Station with NQ.
A Camp 1981
fl Blue Ice Field
?5.0 Ablation rate [cm/yr]
FIGURE 11.?Map of the Allan Hills Main Icefield with the triangulation network. Numbers
associated with the stations are measured ablation rates in cm/year. The insert shows calculated
elevations along the southern border of the network. The highest meteorite concentrations
have been found at the base of the slope that runs through the network between stations 8 and
13.
NUMBER 26 19
FIGURE 12.?View along the Allan Hills in a northerly
direction. The tripod (left lower corner) has been installed
over station 1 (Figure 11).
FIGURE 13.?Helicopter view in a southwesterly direction
of the Allan Hills icefield. Visible is the camp site (arrow)
and the "monocline" with a moraine, which supplies the
icefield with terrestrial rocks to confuse a meteorite hunter.
FIGURE 14.?After removal of the station pole, the survey
was carried out from instruments mounted over the hole in
the ice. A shelter protects the Wild T2 theodolite and the
Wild TI4L Distomat from vibrations due to the wind.
triangles (Figure 11) could be measured. The
observations from 1981, as well as those from
previous measurements, were used to calculate
the coordinates of each station relative to sta-
tions 1 and 2, which are positioned in the
bedrock of the Allan Hills. A standard pro-
gram of triangulation networks, ARSM, at the
Fachhochschule Mainz was used for the data
reduction. The attempt to calculate vertical ice
movements was done with a computer pro-
gram developed at the Max-Planck-Institiit in
Mainz. Ablation rates of the ice between two
measurements are given by the differences of
the height of each station pole from the surface
of the ice to the top.
Results and Discussion
ABLATION
The mean ablation rate observed for each
station over three years is given in Figure 11
(Annexstad and Schultz, 1983). The uncertainty
of these numbers is about 1 cm because the
ablation rate around the poles is not uniform.
Also from year to year the ablation rate may vary
due to different wind and temperature condi-
tions. However, a mean ablation rate of about 5
cm/year is well established for the stations on ice
close to the areas with high meteorite concentra-
tions. This observation is basic to all models for
20 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
the transport and concentration of meteorites.
Once buried in the ice, meteorites can emerge
to the surface and, assuming a horizontally stag-
nant icefield over a long period of time, build up
dense meteorite concentrations.
HORIZONTAL MOVEMENTS
Nishio and Annexstad (1980) reported hori-
zontal ice velocities based on observations in
1978 and 1979. Their calculated values have
rather large uncertainties because only one year
of movement was measured. With the 1981 sur-
vey, changes over a three-year period could be
observed and, in addition, the use of the Disto-
mat allowed a better determination of the net-
work. For four selected stations the calculated
coordinates (in arbitrary units) of the measure-
ments in 1978, 1979, and 1981 are shown in
Figure 15. This figure demonstrates that the
Allan Hills
HORIZONAL ICE
MOVEMENT
1978-1981
Stations! O Q
? '78? '79
*"81
. 1m ,
t
FIGURE 15.?Calculated coordinates (in relative units) of
stations 4, 11, 16, and 20 for the measurements in 1978,
1979, and 1981. Due to the application of distance measure-
ments in addition to the angle measurements the uncertain-
ties could be reduced in the 1981 measurement.
[m]
C
0)
(DoO
3JS
a
0) 2
O
ALLAN HILLS
Ice Movement
between
1978 and 1981
3 5 7 9 11 13 15 17 19
Stations
FIGURE 16.?The calculated displacement in an easterly di-
rection of all stations during the period 1978 to 1981.
observational uncertainties could be reduced for
the 1979 and 1981 measurements. The errors
of the horizontal velocities are based mainly on
the uncertainties of the initial measurement.
Figure 16 shows the horizontal displacement
of the stations relative to the 1978 measurement.
The error bars reflect the sum of the uncertain-
ties of the 1978 and 1981 data. Three different
groups can be recognized according to their dis-
placement in an eastward direction between
1978 and 1981. Stations 3 to 7 show, within the
limits of error, no movement in three years. This
area is the firn-covered icefield closest to the
Allan Hills. From stations 8 to 16 the horizontal
velocity of the ice increases from about 10?10
cm/year to about 100?70 cm/year. This is the
area with many meteorite finds. Stations 17 to
20 have the same rate of movement of about 1
m/year.
These measurements corroborate the sugges-
tion that the ice moves into the Allan Hills region
NUMBER 26 21
from the west and becomes stagnant where many
meteorites are found. An additional resurvey of
the network in future years would enhance the
quality of the data, because the 1981 coordinates
with rather small errors could then serve as a
reference. However, to calculate the ice balance
in this region, measurements of the ice thickness
are needed.
VERTICAL MOVEMENTS
The determination of vertical angles in Ant-
arctica is sometimes more difficult than the meas-
urement of horizontal angles, because atmos-
pheric effects can obscure the top of the poles
that are used as targets. Instrumental factors also
have more influence on vertical angle measure-
ments. The vertical angles, therefore, have un-
certainties that exceed the expected movement
of the ice. For example, for stations 9 to 13 the
mean error of the calculated elevations from the
vertical angle measurements are about 90, 40,
and 15 cm for the measurements of 1978, 1979,
and 1981, respectively. A resurvey of these pa-
rameters in a future field season could result in
better data.
Conclusions
The ablation rate of the ice at the Allan Hills
meteorite icefield averages about 5 cm/year.
The ice from the Eastern Antarctic ice sheet
approaching the Allan Hills slows down and be-
comes stagnant. The ice velocity 13 km west of
the Allan Hills is about 1 m/year; at a distance
of about 5 km from the Allan Hills it is almost
zero. The experimental uncertainties are too
high to determine vertical ice velocities; how-
ever, due to rather small errors of the 1981
measurement, a resurvey of the network could
result in useful values for this parameter.
Literature Cited
Annexstad, J.O.
1982. The Allan Hills Icefield and its Relationship to
Meteorite Concentration. In U.B. Marvin and
B. Mason, editors, Catalog of Meteorites from
Victoria Land, Antarctica, 1978-1980. Smith-
sonian Contributions to the Earth Sciences, 24:12-
18.
Annexstad, J.O., and L. Schultz
1983. Measurements of the Triangulation Network
at the Allan Hills Meteorite Icefield. In Proceed-
ings of the Fourth International Symposium on Ant-
arctic Earth Sciences, pages 617-619.
Cassidy, W.A., E. Olsen, and K. Yanai
1977. Antarctica: A Deep-Freeze Storehouse for Me-
teorites. Science, 198:727-731.
Cassidy, W.A., and L.A. Rancitelli
1982. Antarctic Meteorites.
70:156-164.
American Scientist,
Evans, J.C., J.H. Reeves, and L.A. Rancitelli
1982. Aluminum-26: Survey of Victoria Land Mete-
orites. In U.B. Marvin and B. Mason, editors,
Catalog of Meteorites from Victoria Land, Ant-
arctica, 1978-1980. Smithsonian Contributions to
the Earth Sciences, 24:70-74.
Fireman, E.L., L.A. Rancitelli, and T. Kirsten
1979. Terrestrial Ages of Four Allan Hills Meteor-
ites: Consequences for Antarctic Ice. Science,
203:453-455.
Freundel, M., and L. Schultz
In prep. Terrestrial 81Kr Ages of Antarctic Meteor-
ites.
Marvin, U.B.
1981. The Search for Antarctic Meteorites. Sky and
Telescope, 1981:423-427.
Marvin, U.B., and B. Mason, editors
1982. Catalog of Meteorites from Victoria Land,
Antarctica, 1978-1980. Smithsonian Contribu-
tions to the Earth Sciences, 24: 97 pages.
Nagata, T.
1978. A Possible Mechanism of Concentration of
Meteorites within the Meteorite Ice Field in
Antarctica. Memoirs of the National Institute of
Polar Research (Japan), special issue, 8:70-92.
Nishiizumi, K., J.R. Arnold, D. Elmore, X. Ma, D.
Newman, and H.E. Gove
1983. 36C1 and 53Mn in Antarctic Meteorites and
10Be-36Cl Dating of Antarctic Ice. Earth and
Planetary Science Letters, 62:407-417.
Nishio, F., and J.O. Annexstad
1979. Glaciological Survey in the Bare Ice Area near
the Allan Hills in Victoria Land, Antarctica.
Memoirs of the National Institute of Polar Research
(Japan), special issue, 15:13-23.
22 NUMBER 26
1980. Studies on the Ice Flow in the Bare Ice Area Whillans, I.M.
near the Allan Hills in Victoria Land, Antarc- 1982. Meteorite Concentration Mechanism near the
tica. Memoirs of the National Institute of Polar Allan Hills and the Age of the Ice. In C. Bull
Research (Japan), special issue, 17:1-13. and M.E. Lipschutz, editors, Workshop on Ant-
Schultz, L. arctic Glaciology and Meteorites. Lunar and
1982. Antarctische Meteorite. Die Naturwissenschaf- Planetary Institute Technical Report, 82-03:35.
ten, 69:220-225. Houston: Lunar and Planetary Institute.
Descriptions of Stony Meteorites
Roberta Score, Carol M. Schwarz, and Brian Mason
This section provides descriptions of the indi-
vidual specimens, arranged by class. Within the
chondrites, the specimens are grouped according
to the Van Schmus-Wood (1967) classification,
and the descriptions follow the order of increas-
ing petrographic type. The descriptions are
based largely on those published in the Antarctic
Meteorite Newsletter, with additional information
as available. The letter-number designation con-
curs with guidelines recommended by the Com-
mittee on Nomenclature of the Meteoritical So-
ciety; it carries the following information: ALH
(Allan Hills); A80 (Expedition A, 1980); xxx
(digits indicating the number of the specimen).
The original weight of the specimen is given to
the nearest gram (nearest 0.1 gram for specimens
weighing less than 100 grams).
This section comprises material on all charac-
terized meteorites collected during the 1980-
1981 and 1981-1982 field seasons. Specimens
weighing less than 100 grams are listed without
descriptions, unless they show distinctive fea-
tures. A summary account of the petrography of
the 1980-1981 collections has been published
by Mason and Clarke (1982).
Roberta Score and Carol M. Schicarz, Northrop-Houston, Johnson
Space Center, Houston, Texas, 77058. Brian Mason, Department
of Mineral Sciences, National Museum of Natural History, Smith-
sonian Institution, Washington, D.C. 20560.
Chondrites
CLASS C2
FIGURES 17, 18
ALHA81002 (14.0 g).?This is a friable jet
black stone (2.5 X 2.5 X 2.5 cm) of pyramidal
form, without fusion crust. Chondrules and in-
clusions can be distinguished on the surface; a
minute amount of salt deposit was present on
one surface.
ALHA81004 (4.7 g).?Dull black fusion crust,
blistery along one edge, covers most of this stone
(3 X 1.5 X 1 cm). Small white irregular and
rounded inclusions are apparent in the black
matrix; several small oxidation halos were noted.
Thin sections of these specimens are very sim-
ilar to each other and to those of ALHA77306
and 78261, the previously described C2 chon-
drites from the Allan Hills; these four meteorites
may be paired. The sections show numerous
small colorless grains (up to 0.1 mm) and irreg-
ular aggregates (up to 0.6 mm) mainly of olivine,
and a few small chondrules (up to 0.6 mm) in an
opaque to translucent brown isotropic matrix.
Trace amounts of nickel-iron and troilite are
present as widely dispersed minute grains. Micro-
probe analyses of the olivine show a composition
range of Fao to Fa52, mean Fan, with a strong
peak at Fa0 to Fai characteristic for chondrule
24 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 18.?ALHA81004, C2 chondrite. Photomicro-
graph of thin section (area of field is 3 X 2 mm), irregular
grains and rare chondrules, mainly of olivine (white to gray)
in translucent to opaque matrix (black).
FIGURE 17.?C2 chondrites. Note blistery fusion crust
around edge of ALHA81004.
olivine (isolated olivine grains show a wide com-
position range). A few grains of clinoenstatite
and one grain of diopside were analyzed.
FIGURE 19.?ALHA81003, C3 chondrite. Note pitted sur-
face, and white inclusions in black matrix.
CLASS C3
FIGURES 19, 20
ALHA81003(10.1 g).?This stone (2.5X2.0
X 1.5 cm) from the Allan Hills has only one small
area of fusion crust. The exposed surfaces are
black and are dotted with abundant irregular
white inclusions, some of which are rusty. Sparse
metal grains are scattered through the matrix.
The section shows numerous chondrules up to
NUMBER 26 25
FIGURE 20.?ALHA81003, C3 chondrite. Photomicro-
graph of thin section (area of field is 3 X 2 mm); note large
olivine-rich chondrules in brown to black semi-opaque ma-
trix.
3 mm across and irregular crystalline aggregates
up to 2 mm in maximum dimension, set in a
minor amount of dark brown to black semi-
opaque matrix. The chondrules and aggregates
consist mainly of olivine with some polysyntheti-
cally twinned pyroxene. Trace amounts of nickel-
iron are present as minute grains. Sulfide is pres-
ent in minor amount, finely dispersed through-
out the section. Microprobe analyses of chon-
drule olivine show a wide compositional range:
Fa0 to Fa40, mean Fa8; the matrix consists largely
of fine-grained iron-rich olivine, Fa40 to Fa60.
Pyroxene in the chondrules is clinoenstatite,
mostly near Fsi, but with occasional Fe-rich
grains. The meteorite is a C3V chondrite; pre-
viously described C3 chondrites from the Allan
Hills are C3O (Scott et al., 1981).
RKPA80241 (0.6 g).?This small specimen
(1.5 X 0.5 X 0.5 cm) from Reckling Peak has a
little fusion crust. The thin section shows a close-
packed aggregate of chondrules (up to 2.5 mm
across) and irregular granular aggregates, set in
a small amount of black (probably carbonaceous)
matrix. A minor amount of nickel-iron is present,
in several forms: as small grains dispersed
through some chondrules, concentrated around
the margins of some chondrules, and as rare
globules up to 0.8 mm across in the matrix. The
silicate material consists largely of olivine and
polysynthetically twinned clinopyroxene. Well-
preserved fusion crust, up to 1.2 mm thick, rims
part of the section. Weathering is extensive, with
brown limonitic staining pervasive throughout
the section. Microprobe analyses show olivine
and pyroxene with variable composition; for 30
olivine analyses the Fa range is 0.7-5.5 (except
for one of Fa36), and the mean is Fa3; for 15
pyroxene analyses the range is Wo 0.3-1.5, En
90-98, Fs 1-8, with mean of Wo0.7En95Fs4. The
meteorite is tentatively classified as a C3V chon-
drite.
CLASS H3
FIGURES 21, 22
OTTA80301 (35.5 g).?This rounded stone
(3.5x3x2 cm) from Outpost Nunatak is almost
competely covered with brown to black fusion
crust, pitted in places. A broken corner reveals
abundant chondrules and irregular inclusions.
The thin section shows a close-packed aggregate
of chondrules and some irregular granular en-
claves; the matrix consists of fine-grained silicates
with a moderate amount of nickel-iron and a
lesser amount of troilite. Chondrules range up
FIGURE 21.?OTTA80301, H3 chondrite, a rounded stone
almost completely covered with brown to black fusion crust.
26 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 22.?Photomicrographs of thin sections of H3 chondrites (area of each field is 3 X 2
mm): a, RKPA80205; b, OTTA80301. (Closely packed aggregates of chondrules, irregular
enclaves, and mineral grains set in a minor amount of dark matrix.)
to 1.1 mm across, and show a close-packed ag-
gregate of chondrules and some irregular gran-
ular enclaves; the matrix consists of fine-grained
silicates with a moderate amount of nickel-iron
and a lesser amount of troilite. Chondrules range
up to 1.1 mm across, and show a variety of types,
the commonest being granular olivine and oli-
vine-pyroxene (polysynthetically twinned clino-
bronzite), porphyritic olivine, and fine-grained
pyroxene. Some intergranular glass in the chon-
drules is clear and transparent, but much of it is
turbid and partly devitrified. Minor brown li-
monitic staining is present around nickel-iron
grains. Microprobe analyses show olivine and
pyroxene with variable composition: olivine, Fan
to Fa 19, average Fai8; pyroxene, Fs4 to Fsn, av-
erage Fsio.
RKPA80205 (53.8 g).?This stone (4 X 3 X
2.5 cm) is partly covered by dull brownish black
fusion crust; a weathering rind, 1 mm thick, is
present, but the interior is only moderately
weathered. The thin section shows a closely
packed mass of chondrules (0.2-2.4 mm diame-
ter), chondrule fragments, and irregular crystal-
line aggregates, with interstitial nickel-iron and
troilite and a small amount of dark fine-grained
matrix. A considerable variety of chondrules is
present; many are granular to porphyritic olivine
with transparent to turbid intergranular glass;
others consist of granular polysynthetically
twinned clinopyroxene with or without olivine,
fine-grained pyroxene, or barred olivine. Minor
brown limonitic staining is present throughout
the section. Microprobe analyses show olivine
ranging in composition from Fa 17 to Fa2o, with a
mean of Fai8; the pyroxene is low-calcium (CaO
0.1-0.2%) clinobronzite, ranging in composition
from Fs5 to FS13, with a mean of Fsi8.
RKPA80207 (17.7 g).?Dull black fusion
crust covers one surface of this specimen (3 X
2.5 X 1.5 cm); other surfaces are deeply weath-
ered. In thin section, chondrules are abundant,
ranging from 0.3 to 1.5 mm in diameter; a wide
variety is present, the commonest being granular
olivine and olivine-pyroxene, and fine-grained
pyroxene. The granular chondrules have inter-
granular glass, sometimes pale brown and trans-
parent but commonly turbid and partly devitri-
fied. Irregular granular clasts and chondrule
fragments are also present. Most of the pyroxene
is polysynthetically twinned. The matrix consists
of fine-grained olivine and pyroxene, with minor
subequal amounts of nickel-iron and troilite.
Veinlets of limonite and brown limonitic staining
NUMBER 26 27
pervade the section. Microprobe analyses show
olivine ranging in composition from Fa 15 to Fa29,
with a mean of Fa2o (% mean deviation of FeO is
32). Pyroxene composition range from Fs0 to
Fs28, with a mean of Fsi3. [This meteorite is
reclassified H3 from L3 by Scott (p. 76)].
CLASS L3
FIGURES 23, 24, 25, 26, 27
ALHA80133 (3.6 g).?This small stone (2.5
X 1.5 X 1 cm) has no fusion crust but has a
reddish brown weathered surface showing
rounded inclusions. The thin section shows a
close-packed mass of chondrules and chondrule
fragments with a small amount of dark fine-
grained matrix. Chondrules range from 0.3 to
1.5 mm in diameter and show a diversity of type,
the commonest being granular olivine and oli-
vine-pyroxene, barred olivine, and fine-grained
pyroxene. Transparent pale brown glass is pres-
ent in some of the granular chondrules. Much of
the pyroxene is polysynthetically twinned clino-
bronzite. Weathering is extensive, with brown
limonitic staining throughout the section. Micro-
probe analyses show that olivine and pyroxene
have highly variable composition: olivine, Fao.5
FIGURE 23.?ALHA81024, L3 chondrite, a rounded angu-
lar stone with several deep fractures, with a reddish brown
weathered surface.
FIGURE 24.?RKPA80256, L3 chondrite, a fractured stone
partly covered with brownish black fusion crust; the fracture
surface shows a closely packed aggregate of chondrules and
enclaves in dark fine-grained matrix.
to Fa35, mean Fai4; pyroxene, Fs5 to Fs3o, mean
Fsi4. This specimen was originally classified as a
C3 chondrite, but Dr. E.R.D. Scott (personal
communication) has identified it as an L3 chon-
drite, paired with ALHA77011 and many other
L3 chondrites from the Allan Hills.
ALHA81024 (797 g).?This angular speci-
men (10 X 8 X 6.5 cm) is covered with reddish
brown to black fusion crust on all sides except
where eroded away, mainly along fractures. The
interior is reddish brown and appears to be ex-
tremely weathered. The thin section shows a
close-packed aggregate of chondrules, up to 1.5
mm across; a variety of types is present, including
porphyritic olivine, barred olivine, granular oli-
vine and olivine-pyroxene, and fine-grained py-
roxene. Much of the pyroxene is polysyntheti-
cally twinned clinobronzite. Some intergranular
glass within the chondrules is pale brown and
transparent, but commonly is turbid and partly
devitrified. Minor amounts of nickel-iron (largely
altered to brown limonite) and troilite are pres-
ent in the matrix. Olivine and pyroxene have
variable composition. Olivine composition
ranges from Fa3 to Fa28, with a mean of Fai9 (%
mean deviation FeO is 34). Pyroxene composi-
tion ranges from Fs2 to FS24, with a mean of Fsi0
(% mean deviation FeO is 79). Transparent chon-
drule glass has the following mean composition
(weight percent): SiO2 63.3, A12O3 22.5, FeO
0.9, MgO 0.2, CaO 0.2, K2O 3.3, Na2O, 8.8,
28 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 25.?Photomicrographs of thin sections of L3 chon-
drites (area of each field is 3 X 2 mm): a, ALHA80133; b,
ALHA81024; c, RKPA80256. (Closely packed aggregates
of chondrules, irregular enclaves, and mineral grains set in
a minor amount of dark matrix).
FIGURE 26.?ALHA81031, L3 chondrite, a fractured and
weathered stone showing some light-colored angular clasts
on the surface.
TiO2 0.8, MnO 0.03; this composition is close to
anorthoclase.
ALHA81025 (379 g).?This stone (9.5 X 8 X
4.5 cm) is extremely weathered; rounded and'
irregular inclusions (one 7x5 mm) are visible
on the weathered surfaces.
ALHA81030 (1851 g).?Patchy black fusion
crust is present on all surfaces of this angular
stone (18 X 9 X 7.5 cm). Several large fractures
penetrate the interior. Inclusions can be seen on
the exterior and on chipped surfaces.
ALHA81031 (1594 g).?This is an angular
specimen (73 X 9 X 9 cm) with small areas of
thin lustrous black fusion crust. The surface is
weathered dark reddish brown and is penetrated
by numerous fractures.
NUMBER 26 29
FIGURE 27.?ALHA81031, L3 chondrite, an angular weath-
ered stone partly covered with lustrous black fusion crust;
photographed as found.
ALHA81032 (726 g).?Lustrous black fusion
crust is present on small areas of this angular
stone (9x9x6 cm). Light colored clasts or
chondrules up to 0.5 cm across are visible on
weathered surfaces.
The thin section of ALHA81025 shows a
close-packed aggregate of chondrules and chon-
drule fragments up to 3.5 mm across, in a fine-
grained matrix of olivine, pyroxene, troilite, and
a little nickel-iron. Chondrule types include por-
phyritic olivine, granular olivine and olivine-py-
roxene, barred olivine, and radiating pyroxene.
Much of the pyroxene is polysynthetically
twinned clinobronzite. Intergranular glass is
present in the chondrules, usually turbid but
sometimes transparent and purple-brown.
Weathering is extensive, with small areas of
brown limonite throughout the section. Micro-
probe analyses show that olivine and pyroxene
have variable composition. Olivine composition
ranges from Fai to Fa4i, with a mean of Fai8
(percent mean deviation FeO is 76). Pyroxene
composition ranges from Fs3 to Fs40, with a mean
of Fsi5 (percent mean deviation FeO is 75). Pur-
ple glass in a chondrule has the following mean
composition (weight percent): SiO2 56.8, A12O3
24.1, FeO 3.7, MgO 2.4, CaO 0.4, K2O 4.1,
Na2O 8.8, TiO2 1.2, MnO 0.09.
Thin sections of ALHA81025,81030,81031,
and 81032 are so similar in texture, range of
mineral composition, and degree of weathering
that these meterorites can be paired, together
with ALHA77011 (Scott, personal communica-
tion).
RKPA80256 (153 g).?This meteorite (7 X
5.5x3 cm) is almost totally covered with brown-
ish black fusion crust. Chondrules and white and
gray clasts up to 5 mm across are visible on
exposed surfaces. The thin section shows a
closely packed mass of chondrules (0.3-1.8 mm
diameter) and irregular crystalline aggregates.
Some of the chondrules have prominent dark
rims. The sparse matrix is dark and fine-grained,
with a small amount of coarser nickel-iron and
troilite scattered throughout. A notable variety
of chondrules is present; many are granular or
porphyritic olivine and olivine-pyroxene with
transparent to turbid interstitial glass. The py-
roxene is polysynthetically twinned clinobron-
zite. There is a little limonitic staining in associ-
ation with metal grains. Microprobe analyses
show olivine ranging in composition from Fa2o
to Fa25, with a mean of Fa22 (% mean deviation
of FeO is 8.3). The pyroxene is low-calcium (CaO
= 0.1-0.8%), with a composition range of Fsio
to Fs26 and a mean of Fsi8.
CLASS LL3
FIGURE 28
ALHA81251 (158 g).?This meteorite (6.5 X
6 X 2.5 cm) is partly covered with thin lustrous
black fusion crust. Broken surfaces show abun-
dant chondrules up to 5 mm in diameter. The
interior is weathered a deep reddish brown color.
The thin section of ALHA81251 shows a
close-packed aggregate of chondrules and chon-
30 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 28.?Photomicrograph of a thin section of
ALHA81251, an LL3 chondrite (area of the field is 3 X 2
mm). Numerous chondrules, with some angular enclaves
and mineral grains, set in a minor amount of dark matrix.
drule fragments, up to 3 mm in maximum di-
mension. Most of the matrix is black and opaque,
with small grains of olivine and pyroxene; the
black matrix appears to be carbonaceous, with
small amounts of troilite and nickel-iron (largely
weathered to limonite). A wide variety of chon-
drule types is present, including barred olivine,
granular olivine and olivine-pyroxene, and fine-
grained pyroxene. Clear glass is present in barred
olivine chondrules. Microprobe analyses show
olivine and pyroxene with variable compositions:
olivine, Fai to Fa29, mean Fa14 (percent mean
deviation FeO is 64); pyroxene, Fs2 to Fs28, mean
Fsi3 (percent mean deviation FeO is 72). Clear
glass in a barred olivine chondrule has the follow-
ing composition (weight percent): SiO2 61.4,
A12O3 23.5, FeO 1.7, MgO 2.0, CaO 0.4, Na2O
4.8, K2O 1.6, TiO2 1.1, MnO 0.01.
ALHA81251 is tentatively paired with
ALHA76004 (Scott, personal communication).
CLASS H4
FIGURES 29, 30
Four H4 chondrites (ALHA80106, 432 g;
80121, 39.1 g; 80128, 138 g; 80131, 19.8 g)
were collected at the Allan Hills in 1980-1981,
and three (ALHA81022, 912 g; 81044, 386 g;
81048, 190 g) have been identified in the 1981-
1982 collection. Three small specimens were
collected near Reckling Peak in 1980-1981:
RKPA80232, 80.1 g; 80237, 22.2 g; 80267,
24.2 g.
ALHA80106 consists of five fragments, four
of which can be fitted together. Areas of shiny
black fusion crust are present, but areas devoid
of fusion crust are weathered reddish brown, and
weathering appears pervasive throughout the
fragments. ALHA80128 has dull black fusion
crust on all but one surface; several large frac-
tures penetrate the specimen, and the interior is
medium gray speckled with white and dark gray
inclusions. ALHA81022 has thin black fusion
crust over much of the surface; where the inte-
rior is exposed many chondrules are visible.
ALHA81044 and 81048 are severly weathered
and fractured specimens with little or no fusion
crust.
In thin sections these specimens show the typ-
ical features of Class H4 chondrites: well-devel-
oped chondrules, the commonest being granular
and porphyritic olivine and olivine-pyroxene,
barred olivine, and fine-grained radiating pyrox-
ene (much of the pyroxene is polysynthetically
twinned clinobronzite); the groundmass consists
FIGURE 29.?ALHA81022, H4 chondrite, a fractured stone
with thin black fusion crust on the original surface; numer-
ous mm-sized chondrules are visible on the fracture surface.
NUMBER 26 31
FIGURE 30.?Photomicrographs of thin sections of H4 chondrites (area of each field is 3 X 2
mm): a, RKPA80237; b, ALHA81044. (Numerous well-defined chondrules are present, but
some chondrule margins tend to merge with the granular matrix).
of fine-grained olivine and pyroxene, with minor
amounts of nickel-iron and troilite. The Allan
Hills specimens have olivine of essentially uni-
form composition (Fai8 to Fai9) and somewhat
variable pyroxene (Fsi5 to FS22). The
ALHA80xxx specimens are possibly paired;
ALHA81044 and 81048 are probably pieces of
a single meteorite; and ALHA81022 is tenta-
tively paired with ALHA78084 and 77009. The
Reckling Peak specimens have olivine (Fai8 to
Fa 19) and pyroxene (Fsi6) of essentially uniform
composition and are possibly paired.
CLASS L4
FIGURES 31, 32
Two L4 chondrites (RKPA80216, 44.3 g;
80242, 7.3 g) were collected near Reckling Peak
in the 1980-1981 season, and one
(ALHA81040, 194 g) has been identified in the
1981-1982 collection from the Allan Hills.
ALHA81040 is a round stone (5.5 X 5 X 5 cm)
with about 75% of its surface covered with dull
black fusion crust; where fusion crust is lacking
the surface is weathered to a deep reddish brown.
The Reckling Peak specimens are small weath-
ered stones completely or almost completely cov-
ered with fusion crust.
FIGURE 31.?ALHA81040, L4 chondrite, a rounded stone
with much of the surface covered with dull black fusion
crust.
Thin sections of these meteorites show the
typical features of L4 chondrites. Chondritic
structure is well developed, with a variety of
chondrule types; irregular granular aggregates,
possibly chondrule fragments, are also present.
The chondrules are set in a fine-grained matrix
consisting largely of olivine and pyroxene, with
minor subequal amounts of nickel-iron and troil-
ite. Some of the pyroxene, especially in the chon-
drules, is polysynthetically twinned clinobron-
32 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
.>
FIGURE 32.?Photomicrographs of thin sections of L4 chondrites (area of each field is 3 X 2
mm): a, RKPA80216; b, ALHA81040. (Chondritic structure is prominent, but some chondrules
show partial integration with the granular matrix; note barred chondrule within barred
chondrule in RKPA80216).
zite. Olivine and pyroxene are essentially uni-
form in composition: olivine, Fa23 to Fa25; pyrox-
ene, Fsi9 to Fs2i. The Reckling Peak specimens
resemble each other closely in mineralogical
compositions, texture, and degree of weathering,
and are possibly paired.
CLASS H5
FIGURES 33, 34
Six H5 chondrites were collected at the Allan
Hills in the 1980-1981 season, but only one
(ALHA80132, 152 g) weighs more than 100 g.
ALHA80132 (8 X 4.5 X 3 cm) is a flat stone
largely covered with dull brownish black fusion
crust with prominent flow bands on one surface:
it is considerably fractured and has a thick weath-
ering rind. Nine have been identified in the
1981-1982 collection, all weighing more than
100 g. Nineteen were collected near Reckling
Peak in 1980-1981, but most were small speci-
mens; the only ones larger than 100 g are
RKPA80220 (124 g) and 80233 (413 g).
RKPA80220 is a complete stone (5.4 X 4 X 3
cm) entirely covered with thin patchy fusion
crust; several fractures penetrate the interior,
which is considerably weathered. RKPA80233
FIGURE 33.?ALHA81015,an H5 chondrite, photographed
as found.
(8.5 X 6.5 X 5 cm) has one planar fracture
surface, and the rest of the surface is covered
with patches of fusion crust; the fracture surface
contains numerous chondrules, which can
easily be plucked out. Most of the 1981-1982
H5 chondrites from Allan Hills (ALHA81015,
81019, 81020, 81033, 81034, 81036, 81039,
NUMBER 26 33
FIGURE 34.?ALHA81033, H5 chondrite, photomicro-
graph of thin section (area of field is 3 X 2 mm); chondritic
structure is well developed, but margins of chondrules tend
to merge with the granular groundmass.
81042, 81067) are individual stones partly cov-
ered with fusion crust. ALHA81033 consists of
six weathered fragments. ALHA81039 (10 X 4.5
X 4 cm) consists of two pieces, which fit together,
and a small additional piece; black fusion crust is
present on most of the original surface, and a
weathering rind is present on fracture surfaces,
but the interior is light gray and only slightly
weathered. ALHA81067 (7 X 5.5 X 4 cm) was
collected as two pieces, which fit together per-
fectly but do not form a complete stone; some
patchy fusion crust is present on original sur-
faces, and fracture surfaces are deeply weathered
to an iridescent red-brown color.
In thin sections all the H5 chondrites show a
generally well-developed chondritic structure
with a variety of chondrule types, including gran-
ular and porphyritic olivine and olivine-pyrox-
ene, barred olivine, and fine-grained pyroxene.
Chondrule margins may be somewhat diffuse,
tending to merge with the granular groundmass,
which consists largely of olivine and pyroxene,
with minor amounts of nickel-iron and troilite;
minute grains of sodic plagioclase can sometimes
be detected. The compositions of the olivine
(Fai6 to Fa i9) and orthopyroxene (Fsi4 to Fsi7)
are uniform within the individual specimens.
The Reckling Peak H5 chondrites resemble
each other in texture, mineral compositions, and
degree of weathering; RKPA80220 and 80223
have been tentatively paired, as have RKPA
80250 and 80251, and further research will
probably extend these pairings. The Allan Hills
1980-1981 H5 chondrites, except ALHA
80123, are also very similar in texture, mineral
compositions, and degree of weathering, and are
tentatively paired; ALHA80123 is more severely
weathered and may be a different fall. Possible
pairings among the Allan Hills 1981-1982 H5
chondrites remain to be studied.
CLASS L5
FIGURES 35, 36, 37
Three small L5 chondrites were collected near
Reckling Peak in the 1980-1981 season: RKPA
80209 (9.7 g), 80228 (11.1 g), 80268 (3.4 g);
they are individual stones partly or completely
covered with fusion crust. Three L5 chondrites
have been identified in the 1981-1982 Allan
Hills collection: ALHA81017 (1434 g), 81018
(2236 g), 81023 (418 g). ALHA81017 consists
of two pieces (13.5 X 8 X 7 cm and 10 X 9 X 5.5
cm), which do not fit together but are clearly
parts of a single stone. Each piece has small areas
of dark fusion crust and are somewhat weath-
FIGURE35.?ALHA81018, L5 chondrite, an angular
weathered stone partly covered with dull black fusion crust.
34 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 36.?ALHA81023, L5 chondrite, found as fragments with remnants of black fusion crust.
FIGURE 37.?Photomicrographs of thin sections of L5 chondrites (area of fields is 3 X 2 mm):
a, RKPA80209; b, ALHA81023. (Chondrules are prominent, but show some integration with
the granular groundmass; note well-preserved fusion crust on RKPA80209).
ered, with oxidation halos around metal grains.
ALHA81018 is an angular stone (13.5 X 11 X
10 cm) partly covered with dull black fusion
crust; several fractures penetrate the stone, and
a weathering rind approximately 10 mm thick is
present. ALHA81023 was found as two large
pieces, two small pieces, and many tiny chips;
none of the pieces fit together, but they are
NUMBER 26 35
clearly related. Remnants of fusion crust are
present. The interior is light gray and shows
many dark colored chondrules and irregular in-
clusions.
In thin sections the L5 chondrites show a gen-
erally well-developed chondritic structure, with
a variety of chondrule types, including porphyr-
itic olivine, granular olivine and olivine-pyrox-
ene, and radiating fine-grained pyroxene. Chon-
drule margins are often diffuse, tending to merge
with the granular groundmass, which consists
largely of olivine and pyroxene with minor sub-
equal amounts of nickel-iron and troilite. The
compositions of the olivine (Fa23 to Fa25) and
orthopyroxene (Fs]9 to Fs2i) are essentially uni-
form within the individual specimens.
ALHA81017, 81018, and 81023 are very sim-
ilar in all respects, and the possibility of their
being paired should be considered.
CLASS LL5
FIGURE 38
Two LL5 chondrites were collected near Rec-
kling Peak during the 1980-1981 field season
RKPA80234 (136 g) and RKPA80253 (4.6 g).
Although they show some similarities, there are
sufficient differences to indicate that they are
probably not paired: 80253 is practically un-
weathered, whereas 80234 is considerably weath-
ered, with extensive brown limonitic staining.
RKPA80234 is a flat stone, 6 X 5 X 2 cm, with
fusion crust on one surface; the other surfaces
have weathered to a reddish brown color. In thin
sections chondritic structure is barely discernible,
the sparse chondrules being largely obscured by
extensive brecciation. The section shows an ag-
gregate of olivine and pyroxene, with a little
troilite and nickel-iron. Microprobe analyses
gave the following compositions: olivine, Fa26;
orthopyroxene, Fs22.
RKPA80253 is a small flat stone, 2X2X1
cm, almost totally covered with black fusion
crust, blistery in places; the interior has a whitish
gray color and contains many dark angular inclu-
sions. In thin section chondrules are fairly abun-
dant, and are relatively large, ranging up to 3
mm in diameter. Brecciation is prominent, and
many of the chondrules are fractured and de-
formed. Only a little nickel-iron is present. Mi-
croprobe analyses gave the following composi-
tions: olivine, Fa27; orthopyroxene, Fs22 with a
few more Mg-rich grains; plagioclase, Ani0. This
FIGURE 38.?Photomicrographs of thin sections of LL5 chondrites (area of fields is 3 X 2 mm):
a, RKPA80234; b, RKPA80253. (Chondritic structure is somewhat obscured by the extensive
brecciation these meteorites have experienced).
36 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
meteorite is classified as an LL5 chondrite, but
different areas of the brecciated structure show
features of higher and lower type.
CLASS E5
FIGURE 39
RKPA80259 (20.2 g).?Thin iridescent fusion
crust covers most of this small stone (2.5 X 1.5
X 1.5 cm). The interior is dark colored and
weathered, and shows a small amount of a white
evaporite deposit. In thin section chondrules are
rare and barely discernible, the meteorite con-
sisting largely of fine-grained enstatite (mean
grain size approximately 0.05 mm), with some
nickel-iron and troilite. Weathering is very ex-
tensive, with much red-brown limonite through-
out the section. The silicate material is blackened
by the presence of finely dispersed troilite, prob-
ably the result of an episode of severe shock.
Microprobe analyses showed that the enstatite is
almost pure MgSiOg, with minor amounts of
A12O3 (0.1-0.3%), FeO (0.1-0.5%), and CaO
(0.5-0.8%.).
CLASS H6
FIGURES 40, 41
Four H6 chondrites were collected at the Allan
Hills in the 1980-1981 season: ALHA80118,
80122, 80126, 80130. Each weighs less than 100
g; 81022, 80126, 80130 are very similar and are
probably pieces of a single meteorite, but 80118
is less weathered and is probably a different fall.
Six H6 chondrites have been identified in the
1981-1982 collection: ALHA81035 (256 g),
81037 (320 g), 81038 (229 g), 81093 (271 g),
81102 (196 g), 81111 (210 g). ALHA81035 is a
complete stone, 7.5 X 5.5 X 3 cm, entirely cov-
ered with patchy fusion crust; it is extensively
weathered. ALHA81037 is an angular specimen,
7.5 X 6 X 4 cm, with fusion crust on all but two
sides; it is polygonally fractured, and the interior
shows moderate weathering with rusty halos
around metal grains. ALHA81038 is a rounded
oblong stone, 7x4x4 cm, with remnants of
fusion crust; several fractures penetrate the in-
terior, which is extensively weathered. ALHA
81093 is an equidimensional stone, 6 X 5.5 X 4
cm, completely covered with dull black fusion
crust. ALHA81102 is a weathered stone, 7.5 X
FIGURE 39.?RKPA80259, E5 chondrite, photomicrograph
of thin section (area of field is 3 X 2 mm); an enstatite
chondrule (center) in a matrix consisting largely of enstatite
grains (white) with nickel-iron and sulfide (black).
FIGURE 40.?ALHA81035, H6 chondrite, photomicro-
graph of thin section (area of field is 3 X 2 mm); chondritic
structure is barely discernible, the chondrules merging with
the granular groundmass.
NUMBER 26 37
FIGURE 41.?H6 chondrites.
5x3 cm, with thin remnant fusion crust; most
of the surface is oxidized to a dark red-brown
color. ALHA81111 is a rounded stone, 8 X 6 X
4 cm; the upper half is covered with frothy black
fusion crust, the lower half is weathered to an
iridescent brown color.
Nineteen H6 chondrites were collected near
Reckling Peak in the 1980-1981 season; they all
weigh less than 100 g except RKPA80201 (813
g) and 80231 (238 g). RKPA80201 is a rectan-
gular stone, 12 X 6 X 5.5 cm, almost completely
covered with black fusion crust showing polygo-
nal fractures; minute amounts of white evaporite
deposits are present in some of the fractures.
RKPA80231 is a weathered and fractured stone,
7x5x3 cm, with remnants of dull black fusion
crust. All the Reckling Peak specimens except
RKPA80201 are paired because of their similar
and characteristic texture. Specifically they ap-
pear to have been considerably fractured and the
minerals partly granulated; this feature has been
made more prominent by extensive weathering,
which has developed numerous thin limonite
veinlets throughout the specimens.
All the H6 chondrites show very similar petro-
graphic features. Chondrules are sparse and
poorly defined, tending to merge with the gran-
ular groundmass, which consists mainly of olivine
and pyroxene, with minor amounts of nickel-
iron, troilite, and sodic plagioclase. Compositions
38 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
of the olivine (Fan to Fa2o) orthopyroxene (Fsi5
to Fsi7), and plagioclase (Ani2 to Ani3) are uni-
form within the individual specimens.
CLASS L6
FIGURES 42, 43
Fifteen L6 chondrites were collected at the
Allan Hills in the 1980-1981 season, 12 weigh-
ing more than 100 g each. Macroscopic exami-
nation indicated that they might be paired as
pieces of a single meteorite, and this has been
supported by evidence from thin sections, which
shows that they are identical in texture, mineral
compositions, and degree of weathering. Three
L6 chondrites have been identified in the 1981 ?
1982 Allan Hills collection: ALHA81016 (3850
g), 81026 (515 g), 81027 (3835 g). ALHA81016
is a rounded stone, 15X12X11 cm, with
remnants of fusion crust; most of the surface is
smooth and weathered to a dark reddish brown
color; the interior is a lighter brown-green color.
Mineral grains with cleavage faces and distinct
chondrules up to 4 mm across are visible on both FIGURE 42.?ALHA81016, an L6 chondrite, photographedas found.
FIGURE 43.?Photomicrographs of thin sections of L6 chondrites (area of each field is 3 X 2
mm): a, RKPA80202, b, RKPA80252. (Chondritic structure is barely discernible, the chon-
drules merging with the granular groundmass; the dark glassy veinlet in RKPA80202 contains
clear isotropic material tentatively identified as ringwoodite and majorite).
NUMBER 26 39
exterior and interior surfaces. ALHA81026 is a
knobby stone, 11 X 6 X 5.5 cm, partly covered
with dull black fusion crust; the interior is pale
gray, with brown limonitic halos around metal
grains. ALHA80127 consists of two pieces that
fit together as an incomplete rounded stone, 17
X 11.5 X 10 cm; patchy fusion crust covers much
of the surface, and the interior is extensively
weathered. This meteorite has been shocked and
plagioclase converted to maskelynite, with CaO
content equivalent to Ani0 but with Na2O low
and variable, 4.0-5.2%.
Seven L6 chondrites were collected in the
Reckling Peak area during the 1980-1981 field
season; only one, RKPA80202 (544 g) weighs
more than 100 g. All the Reckling Peak speci-
mens except RKPA80215 are identical in tex-
ture, mineral compositions, and degree of weath-
ering, and most of them have dark glassy veinlets
containing clear isotropic grains tentatively iden-
tified as ringwoodite and majorite; these speci-
mens are probably all pieces of a single meteorite
and can be paired with RKPA78001, 78003,
79001, and 79002. RKPA80215 is much more
weathered than the other Reckling Peak L6
chondrites, and appears to be more heavily
shocked, the mineral grains being comminuted
and traversed by shock veinlets of troilite.
CLASS LL6
FIGURE 44
Four LL6 chondrites were collected from the
Reckling Peak area in the 1980-1981 field sea-
son: RKPA80222 (6.9 g), 80235 (261 g), 80238
(18.4 g), 80248 (11.3 g). RKPA80222, 80238,
and 80248 were paired on the basis of macro-
scopic examination, and this has been confirmed
by the evidence from the thin sections. They
show the brecciated structure characteristic of
many LL chondrites. Chondritic structure is
barely discernible, the specimens consisting of a
granular aggregate of olivine and pyroxene, with
minor amounts of plagioclase and troilite, and a
little nickel-iron; some of the nickel-iron is pres-
ent as unusually large grains, up to 3 mm. A
small amount of limonitic staining is present
around the metal grains. RKPA80235 differs in
being unbrecciated, having less troilite and
nickel-iron (without limonitic staining), and hav-
ing somewhat higher Fa and Fs contents in oli-
vine and pyroxene (Fa30 vs. Fa28, FS24 vs. FS23).
FIGURE 44.?Photomicrographs of thin sections of LL6 chondrites (area of each field is 3 X 2
mm): a, RKPA80222; b, RKPA80238. (Chondritic structure is barely discernible, being
obscured by extenisve brecciation and integration with the granular matrix).
40 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 45.?ALHA81021, E6 chondrite, photographed as found; a rounded stone covered
with thin black fusion crust showing flow lines.
CLASS E6
FIGURES 45, 46
ALHA81021 (695 g).?This stone (12 X 9 X
3 cm) is smooth and flat, with thin black fusion
crust with flow lines on the upper surface; the
lower surface is considerably weathered and
some of the fusion crust removed, leaving a
smooth red-brown surface. Only traces of chon-
dritic structure are visible in a thin section, which
consists largely of granular enstatite, with consid-
erable nickel-iron (~20%), minor troilite and
plagioclase, and accessory sinoite (Si2N2O, iden-
tified by its high birefringence). Weathering is
extensive, with brown limonitic staining through-
out the section. Remnants of fusion crust are
present. Microprobe analyses show the enstatite
is almost pure MgSiO3 (CaO 0.8%, FeO 0.2%,
FIGURE 46.?ALHA81021, E6 chondrite, photomicrograph
of thin section (area of field is 3 X 2 mm); a radiating
enstatite chondrule is enclosed in a field of granular enstatite
(white to gray), nickel-iron and sulfides (black).
NUMBER 26 41
A12O3 0.2%); plagioclase is Ani5Or4; the metal
contains about 2% Si.
Achondrites
EUCRITES
FIGURES 47, 48, 49
At the Allan Hills in 1980-1981 one eucrite
(ALHA80102, 471 g) was collected, and in
1981-1982 several more (ALHA81001, 52.9 g;
81006, 254 g; 81007, 163 g; 81008, 43.8 g;
81009, 229 g; 81010, 219 g; 81011, 405 g;
81012, 36.6 g).
ALHA80102 (12.5 X 8 X 5. cm) has areas of
shiny black fusion crust, except on a fracture
surface; many vugs, ranging in size from less than
1 mm to greater than 1 cm, are present, typical
of Allan Hills polymict eucrites. The interior is
medium gray with mm-sized and larger white,
yellow, and black clasts throughout. ALHA
81001 is a small stone (4.5 X 4.5 X 4.0 cm) with
lustrous black fusion crust on two surfaces; the
interior is highly fractured and is quite unlike
other eucrites in being glassy and smoky gray in
FIGURE 47.?ALHA81006, a polymict eucrite, photo-
graphed as found.
color. ALHA81006 (11 X 4.5 X 3.5 cm) is an
elongated stone covered with shiny black fusion
crust except on a fracture surface; this surface
has mm-size patches of fusion crust, indicating a
late breakup in the atmosphere. It is a typical
polymict eucrite and has two notably large clasts
(7 X 11 mm and 15 X 13 mm). ALHA81007
(8.5 X 6 X 2.5 cm) and 81008 (5 X 3.5 X 3 cm)
are similar. ALHA81009 (7 X 5.5 X 3.5 cm) is a
hemispherical stone almost completely covered
with lustrous black fusion crust. ALHA81010(8
X 55.5 cm) is similar. ALHA81011 (8 X 65 cm)
is a rounded stone with scattered remnants of
black fusion crust; it is unusual in containing
numerous large clasts up to 2 cm across. Several
different types are present?typical eucritic
clasts, recrystallized pinkish white clasts, massive
gray clasts?and they range in shape from
rounded to rectangular to lens-shaped.
ALHA81012 (5 X 2 X 3 cm) is a lens-shaped
stone typical of the Allan Hills polymict eucrites.
ALHA80102, 81006, 81007, 81008, and
81010 are very similar in all respects and are
probably paired with previously described Allan
Hills polymict eucrites. The following descrip-
tion of the thin section of ALH A81010 is typical
of all of them. The meteorite is a microbreccia,
consisting largely of angular monomineralic py-
roxene and plagioclase clasts up to 4 mm in
maximum dimension, and a few lithic clasts, in a
matrix of comminuted pyroxene and plagioclase.
Transparent brown fusion crust rims part of the
section. The pyroxene is light to dark brown
pigeonite; a few grains show exsolution lamellae.
The lithic clasts have a maximum dimension of
3 mm, and consist of pigeonite and plagioclase
with ophitic and gabbroic textures; one clast
consists of angular pigeonite and plagioclase
grains in a semi-opaque glassy matrix. Micro-
probe analyses show pigeonite and augite with a
wide range of compositions: Wo5 to Wo36, En2e
to En6i, Fs3i to FS57; plagioclase composition
range is An78 to An93, mean An8g.
ALHA81009 and 81012 resemble each other
closely and are tentatively paired. Thin sections
consist largely of brown grains of pigeonite up
to 1 mm and colorless grains of plagioclase up to
42 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 48.?Eucrites.
NUMBER 26 43
A\;.'
'3 ..' *?-7T ? ^^^
FIGURE 49.?Photomicrographs of thin sections of eucrites (area of each field is 3 X 2 mm):
a, ALHA81001; b, ALHA81006; c, ALHA81011; d, ALHA81012; e, RKPA80204;
/, RKPA80224.
44 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
2 mm in a comminuted groundmass of these
minerals. Some lithic clasts, up to 3 mm across,
are present; most show fine-grained ophitic tex-
tures, but a few have coarse gabbroic textures.
Microprobe analyses show pyroxene compo-
sitions ranging fairly continuously from
Wo3En35Fs62 to Wo4oEn26Fs3o, with the En con-
tent showing a limited range (26-40). Plagioclase
composition range is An75 to An93, mean An86.
These eucrites differ from previously described
polymict eucrites from the Allan Hills in the
range and distribution of pyroxene compositions.
ALHA81011 is a breccia of eucritic clasts up
to 10 mm in maximum dimension, the clasts
sitting in a minor amount of dark glass filled with
comminuted grains of pyroxene and plagioclase.
The clasts consist of pyroxene and plagioclase
and show a variety of textures: finely granular,
subophitic, and gabbroic. Microprobe analyses
show pyroxene compositions corresponding to
pigeonite and augite and clustering around
two mean compositions, Wo4En36Fs6o and
Wo35En32Fs33, with a few intermediate values.
Plagioclase has fairly uniform composition, An87
to An9i, mean An88. The meteorite is a eucritic
breccia; although it appears to be polymict, the
uniformity of mineral compositions suggests a
considerable degree of equilibration, and it may
be a genomict breccia.
ALHA81001 appears to be a new type of
eucrite. The thin section is translucent in pale
brown-gray, with some darker areas, giving a
patchy appearance. With crossed polars the ma-
terial is seen to consist of pyroxene prisms up to
0.5 mm long, mostly with straight extinction, in
a glassy groundmass. No opaque minerals are
present. Microprobe analyses show the pyroxene
has rather uniform composition, averaging
Wo16En4oFs59, with 0.4% A12O3, 0.2% TiO2,
0.9% MnO, and 0.6% Cr2O3. Broad-beam anal-
yses give an approximate bulk composition
(weight percent) as follows: SiO2 (49), A12O3 (14),
FeO (18), MgO (6.7), CaO (10), Na2O (0.2), K2O
(0.1), TiO2 (0.9), Cr2O3 (0.6), MnO (0.7). This
composition agrees with that of an average eu-
crite except that Na2O is lower (in most eucrites
Na2O is about 0.5%); however, the texture is
quite different from any described eucrite. The
overall impression from the texture is that the
material represents a rapidly quenched melt.
Two eucrites were collected in 1980-1981
near Reckling Peak: RKPA80204 (15.4 g) and
80224 (8.0 g).
RKPA80204 (3X2X2 cm) is partly covered
with black fusion crust. Two texturally distinct
lithologies were noted on the surface: one is
massive and fine-grained with rounded yellow
clasts, the other appears to be coarser-grained,
with abundant light and dark grains. Thin (1
mm) black veins extend into both textures.
Abundant vugs give the exterior a rough surface.
The thin section shows clasts (up to 6 mm in
maximum dimension) of subophitic intergrowths
of pigeonite and plagioclase, separated by veins
of coarser grained pigeonite and plagioclase. The
plagioclase laths in the clasts range up to 0.5 mm
in length. The pigeonite and plagioclase grains
in the veins average about 0.3 mm in maximum
dimensions. Microprobe analyses show pigeonite
with a limited range of composition (Wo4Fs57En39
to Woi3Fs52En35). Plagioclase ranges in composi-
tion from An85 to An94, with a mean of An92.
Accessory ilmenite and titanian chromite (TiO2
10-13%) are present. The relative uniformity of
composition of pyroxene and plagioclase indi-
cates that this specimen may be classified as a
monomict eucrite.
RKPA80224 is a small specimen (3.5 X 1.5 X
1.0 cm) partly coated with shiny black fusion
crust. The thin section shows an ophitic inter-
growth of pigeonite and plagioclase, with acces-
sory amounts of tridymite and opaque minerals;
the average grain size of pyroxene and plagio-
clase is about 1 mm. The pyroxene and plagio-
clase crystals are somewhat granulated and show
undulose extinction. A little limonitic staining is
present in one area. Microprobe analyses show
pigeonite with an average composition of
WoioFs54En36; some grains show exsolution la-
mellae of augite with composition Wo44Fs25En30.
Plagioclase ranges in composition from An85 to
An9i, with a mean of An89. The opaque minerals
are troilite, ilmenite and titanian chromite (TiO2
13-15%). The meteorite is a monomict eucrite.
NUMBER 26 45
UREILITES
FIGURES 50, 51
The only ureilite in the 1980-1981 collection
(and the first from the Reckling Peak area) is
RKPA80239, a 5.6 g specimen. Thin patchy
fusion crust is present on all surfaces; areas de-
void of fusion crust are crystalline, reddish brown
A 4
FIGURE 50.?RKPA80239, ureilite, photomicrograph of
thin section (area of field is 3 X 2 mm); olivine (white,
without cleavage cracks) and pyroxene (light gray, with
cleavage cracks), bordered by black material consisting
largely of carbon.
FIGURE 51.?ALHA81101, ureilite, photomicrograph of
thin section (area of field is 3 X 2 mm); olivine (white to
gray, showing mosaic structure), bordered by black material
consisting largely of carbon.
in color, and rough in texture. The thin section
shows an aggregate of subhedral to anhedral
grains (0.3-1.5 mm across) of olivine with minor
amounts of pyroxene. The grains are rimmed
with black carbonaceous material. Trace
amounts of troilite and nickel-iron are present,
the latter largely altered to translucent brown
limonite concentrated along grain boundaries.
Microprobe analyses show olivine of uniform
composition (Fai6) with notably high CaO con-
tent (0.3-0.4%); the pyroxene is a pigeonite of
composition \V05Fs15En80. This meteorite ap-
pears to be relatively lightly shocked compared
to most ureilites.
ALHA81101 is a 119 g specimen, 7.2 X 4.5 X
3 cm, with thick black fusion crust on two sides.
The section shows an aggregate of subhedral to
anhedral crystals of olivine, 1-3 mm across; they
are rimmed with dark carbonaceous material.
Pyroxene, if present, is in small amount. Acces-
sory nickel-iron is present, as minute grains along
crystal boundaries and fractures; it is partly al-
tered to brown limonite. Under crossed polars
the olivine crystals are seen as a mosaic of tiny
grains averaging 0.05 mm across, evidently a
shock effect. Microprobe analyses show olivine
of variable composition, Faio to Fa22, mean Fai9.
This urelite differs from previously described
ureilites from the Allan Hills in the mosaic tex-
ture of the olivine.
ACHONDRITE, UNIQUE
FIGURES 52, 53, 54
ALHA81005 (31.4 g).?At the time of collec-
tion this specimen was noted as unusual, because
of the greenish glassy fusion crust and the pres-
ence of prominent clasts. The stone is rounded,
equidimensional (3 X 3 X 2.5 cm) and the crust
shows flow markings; the interior consists of
abundant angular white clasts up to 8 mm across,
set in a dark glassy matrix. In thin sections the
matrix is a translucent to semi-opaque dark
brown glass and shows flow structure in places;
clast: matrix ratio is approximately 40:60. The
larger clasts are polymineralic, the smaller (less
than 0.3 mm) may be individual mineral grains.
46 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 52.?ALHA81005, anorthositic breccia, showing
fusion crust and brecciated nature of interior.
The clasts consist largely of plagioclase, together
with some pyroxene and occasional olivine; most
of the mineral grains are plagioclase. The clasts
show a variety of textures, including gabbroic,
diabasic, and basaltic; many have been shocked
and partly granulated. Some of the clasts resem-
ble eucrites, but many appear to be more feld-
spathic than most eucrites. The section is notable
for the complete absence of opaque minerals,
except for a 1 mm metal grain. Microprobe
FIGURE 53.?ALHA81005, anorthositic breccia, after lab-
oratory splitting, showing white anorthositic clasts in dark
glossy matrix.
analyses show that the plagioclase is very Ca-rich,
averaging An97 (range An95 to An98); pyroxene
is variable in composition, Wo 1-41, En 44-79,
Fs 7-47 (richer is En than most eucrite pyrox-
enes); several grains of olivine, Fa 11-40, were
analyzed. The MnO/FeO ratio in pyroxene
grains differs from that in eucrite pyroxenes and
agrees with that in lunar pyroxenes. The mete-
orite closely resembles many of the Apollo 16
lunar breccias.
FIGURE 54.?ALHA81005, anorthositic breccia, photomicrograph of thin section (area of field
is 3 X 2 mm): a, section showing remnants of fusion crust and clasts in dark glassy matrix; b,
section showing clasts and small clear glass bead.
NUMBER 26 47
This specimen has been the object of intensive
investigation, the preliminary results of which
were presented at the Fourteenth Lunar and
Planetary Science Conference in Houston in
March 1983. Twenty-two papers were given (the
abstracts have been published as LPI Contribu-
tion 501 and are available from the Lunar and
Planetary Institute, 3303 NASA Road One,
Houston, Texas 77058). The results confirmed
and extended the preliminary results recorded
above, and confirmed a lunar origin for this
meteorite. For additional information see Marvin
(p. 95).
Literature Cited
Mason, B., and R.S. Clarke, Jr.
1982. Characterization of the 1980-81 Victoria Land
Meteorite Collections. Memoirs of the National In-
stitute of Polar Research (Japan), special issue,
25:17-33.
Scott, E.R.D., GJ. Taylor, P. Maggiore, K. Keil, S.G.
McKinley, and H.Y. McSween
1981. Three CO3 Chondrites from Antarctica?Com-
parison of Carbonaceous and Ordinary Type 3
Chondrites. Meteoritics, 16:385.
Van Schmus, W.R., and J.A. Wood
1967. A Chemical-Petrographic Classification for the
Chondritic Meteorites. Geochimica et Cosmochimica
Ada, 31:747-765.
Descriptions of Iron Meteorites
and Mesosiderites
RoyS. Clarke, Jr
This section provides brief descriptions of two
octahedrites, a hexahedrite, an ataxite, and a
mesosiderite collected during the 1980 and the
1981 field seasons. The descriptions are prelim-
inary and based largely on material prepared for
publication in the Antarctic Meteorite Newsletter.
Also included is a well-studied mesosiderite, RKP
A79015, from the 1979 season that was not
included in the previous publication in this series.
Octahedrites
RKPA80226 (160 g).?This dark reddish
brown specimen (4.3 X 3.2 X 2.8 cm) from the
Reckling Peak area is slightly smaller than a hen's
egg and is more irregularly shaped. The top
surface is covered with pits 2 to 3 mm in length,
and it is gently and uniformly convex. Distribu-
tion of pits seems to have been controlled in part
by the internal Widmanstatten structure. This
surface, and the bottom surface, have been
strongly affected by terrestrial weathering. The
bottom surface is less uniform in shape and more
convex. Part of it has a pattern of pits similar to
that on the top. However, much of the bottom
surface is dominated by a pattern of parallel
ridges approximately 1 mm apart standing out
in relief, an expression of the Widmanstatten
structure of the material.
A median slice of approximately 6 cm2 was
Roy S. Clarke, Jr., Department of Mineral Sciences, National
Museum of Natural History, Smithsonian Institution, Washington,
D.C. 20560.
polished and microetched. This revealed a heat-
altered zone surrounding the edge of the slice as
deep as 3.5 mm in one area. A well-developed
Widmanstatten pattern is present with a kamacite
band width in the 1.2 mm range. The length/
width ratio for these lamellae is about 7. Some
Neumann bands are present in the kamacite, as
are rhabdites, grain-boundary schreibersites and
subgrain boundaries. No epsilon structure or
troilite was observed. Taenite bands occupy
much of the kamacite grain boundaries, and tae-
nite-kamacite and plessite fields are present. The
plessite areas are mainly pearlitic, suggesting the
possibility that the entire specimen is heat-al-
tered. It is a medium octahedrite containing 8.5
wt.% Ni.
ALHA81014 (188 g).?This specimen (6.5 X
3X2 cm) from the Allan Hills is an irregularly
shaped individual somewhat resembling a fish. It
is covered with a uniformly pitted, dark reddish
brown, iridescent, secondary iron oxide coating.
A surface area of approximately 4.5 cm3 was
microetched. The section was taken perpendic-
ular to the long axis of the specimen near the
more massive end. The edge of the section con-
tains a thin, intermittent border of oxide. Below
this is a heat-altered zone up to 1 mm thick that
is present, with the exception of a few small gaps,
around the complete section. Remnant fusion
crust was not observed. Kamacite has a rather
uniform matte surface at low magnification that
can be resolved with higher magnification to a
fine epsilon-decomposition structure. A system
of wider than average kamacite lamellae, con-
49
50 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
taining frequent centered schreibersites in the
100 X 200 ixm size range, is a prominent feature.
Kamacite lamellae, free of centered schreiber-
sites, have widths in the 0.3 mm range. Plessite
fields occupy approximately two-thirds of the
surface. Interiors of larger fields contain cellular
plessite framed in martensite with taenite bor-
ders. Narrow plessite fields have only martensitic
areas with taenite borders. Schreibersite is also
occasionally present at taenite borders, and as
grain boundary schreibersite bridging adjoining
plessite areas. Occasional 5 to 10 nm schreiber-
sites are present within plessite fields. Other in-
clusions were not observed. The specimen is a
fine octahedrite distinct from ALHA78252, the
previously identified fine octahedrite from the
Allan Hills.
Hexahedrite
ALH A81013(17.75 kg).?The highly distinc-
tive external appearance of this specimen (16 X
16X11 cm) from the Allan Hills suggests that it
is a fragment that separated during atmospheric
breakup from a larger mass with cubic cleavage
(Figure 55). Its shape is that of a cube that has
been shortened along one axis by severe and
irregular ablation-sculpturing of one face. This
face is the only one that is deeply sculptured with
thumb-size regmaglypts, giving the impression
that it was part of the exterior surface prior to
fragmentation (Figure 55a). Its opposite face is
approximately square, with slightly rounded
edges, and appears to have been the leading
surface during late stage ablation (Figure 55b).
All surfaces are covered with a thin reddish
brown coating of secondary oxides, which are
somewhat thicker within the deeper depressions
of regmaglypts. Thin cracks several centimeters
long are present on all surfaces and tend to
parallel the cubic planes of the specimen.
A median slice was removed perpendicular to
the square section of the specimen and parallel
to opposite sides. One side of the slice was pol-
ished and macroetched, resulting in an area of
approximately 140 cm2 available for examination
at low magnification. The matrix appears to be
single-crystal kamacite that etches to a dull finish,
atypical for hexahedrites. Several small troilite-
daubreelite inclusions are present, as are a few
small schreibersites. Slight variations in kamacite
reflectivity appear to be due to tiny schreibersites
that are unresolvable at low magnification. The
most prominent surface feature is the system of
orthogonal cracks mentioned above. They pen-
etrate into the interior of the specimen. Neu-
mann bands are absent. This cursory examina-
tion suggests that the meteorite is a hexahedrite
of somewhat unusual metallography. It probably
represents a separate fall, distinct from the typi-
cal hexahedrite ALHA78100.
Ataxite
ALHA80104 (882 g).?This specimen (11 X
7x4 cm) from the Allan Hills is an irregularly
shaped individual. One prominently rounded
surface appears to have been ablation-shaped,
and a second fairly large and comparatively
smooth surface appears to have been the under-
side while the specimen was exposed at the sur-
face of the ice. The meteorite is covered with a
fairly uniform dark reddish brown iron oxide,
and no fusion crust seems to remain. There are
several deep linear incisions into the body of the
meteorite that are possibly due to either prefer-
ential ablation or weathering of schreibersite in-
clusions exposed at the surface.
A microetched surface area of approximately
7 cm2 shows a heat-altered zone over part of the
external surface of the specimen. The metallo-
graphic matrix is a martensitic plessite. Kamacite
spindles less than 0.1 mm wide, and generally
less than ten times their width in length, are
FIGURE 55.?ALHA81013 is a hexahedrite that appears to
have broken out of a larger mass during passage through
the atmosphere, (a) This view looks straight down on the
top surface of the specimen (as it lay on the ice sheet). This
single deeply sculptured face was probably ablated prior to
separation from a larger mass. The square outline of the
specimen is 16 cm on an edge, (b) A tilted view of the bottom
surface; a somewhat modified cube face is still evident, as is
ablation rounding of edges. Cracks following cube directions
may be seen in both photographs.
NUMBER 26 51
52 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
moderately uniformly distributed in a vague
Widmanstatten pattern orientation. The kama-
cite spindles frequently enclose small schreiber-
sites. Three large schreibersite areas are enclosed
in swathing kamacite as wide as 0.2 mm. The
largest such area is 8 mm long. Weathering has
penetrated 0.5 cm into the mass in one area. The
specimen is an ataxite containing 15.9 wt. % Ni,
and it is distinct from ALHA77255, the previ-
ously known ataxite from the Allan Hills.
Mesosiderites
RKPA79015 (10.0 kg).?This specimen (26 X
18X13 cm) from the Reckling Peak area is a
dense mass that has undergone severe external
weathering, resulting in an appearance similar to
that of many weathered iron meteorites. It is
covered with reddish brown iron oxide that is
layered in places and thick enough to flake off in
centimeter-size pieces. No fusion crust remains,
and the original shape of the specimen has un-
doubtedly been somewhat modified. Occasional
cleavage faces of large pyroxene crystals are ex-
posed. It has been described as a mesosiderite by
Prinz et al. (1982) and Clarke and Mason (1982).
The specimen has been divided into two pieces
under clean conditions in a controlled atmos-
phere at the Antarctic Meteorite Curatorial Lab-
FIGURE 56.?RKPA79015, a median slice 15.5 cm wide revealing heterogeneous distribution
of minerals and a brecciated structure. The etched surface reveals large areas of metal and
sulfide, large areas of orthopyroxene that contain material that grades from very coarse to
finely crystalline, and areas rich in troilite that also contain some metal and pyroxene.
NUMBER 26 53
oratory, Lyndon B.Johnson Space Center, Hous-
ton. One piece remains in the protective environ-
ment in Houston. The other piece weighing 5.52
kg was sent to the Smithsonian Institution for
preliminary characterization and distribution to
interested scientists.
The brecciated and heterogeneous character
of RKPA79015 is shown in Figure 56, a photo-
graph of the polished and etched surface of the
slice. The meteorite is composed of major
amounts of metal, orthopyroxene, and troilite,
each with associated minor or trace minerals.
The three major minerals tend to be in close
association with each other, even though in given
areas one mineral may predominate over the
other two.
The silicate minerals present are orthopyrox-
ene of uniform composition (Wo2En74Fs24) and
calcium-rich plagioclase of somewhat variable
composition (An86 to An94). Pigeonite and olivine
have been looked for and not found. Chromite
containing A12O3 7.0%, MgO 1.8%, MnO 1.6%,
and TiO2 0.5% is present, as is merrillite
(Ca9MgNa(PO4)7). The bulk metal composition
is 9.87% Ni, 0.52% Co, 0.15% P, and 2.14%
FeS. Metallic areas consist of polycrystalline kam-
acite with grain boundaries containing cloudy
taenite and schreibersite. Cloudy taenite areas
have thick borders of tetrataenite. These metal-
lographic associations indicate a low temperature
cooling history identical to that of other well-
known mesosiderites. RKPA79015 is apparently
paired with four other silicate-rich fragments
from the same area: RKPA80229, 80246,
80258, and 80263.
ALHA81059 (539 g).?The exterior of this
specimen (9.5 X 5 X 5.5 cm) from the Allan Hills
is severely weathered. Close examination re-
vealed cleavage surfaces of large silicate crystals
within the secondary oxidation products, sug-
gesting that the specimen is a mesosiderite.
A polished thin section consists largely of or-
thopyroxene clasts ranging up to 10 mm in max-
imum dimensions, together with about 30% of
nickel-iron in grains up to 0.6 mm; a little troilite
is present. The meteorite is extremely weathered
and seamed with brown limonite. Microprobe
analyses shows that the orthopyroxene is some-
what variable in composition, ranging from Fs25
to Fs32, with mean of Fs28; mean weight percent
CaO is 1.2, MnO 0.7, A12O3 0.6, TiO2 0.2. Small
amounts of olivine (Fa28), plagioclase (An93), mer-
rillite, and an SiO2 phase (probably tridymite)
were detected with the microprobe. The metal
consists largely of kamacite. Tetrataenite-cloudy
taenite associations are concentrated mainly at
kamacite-silicate boundries. Schreibersite is
either enclosed in the tetrataenite-cloudy taenite
areas or in contact with them. The meteorite is
a mesosiderite, the second from the Allan Hills;
it appears to be different from the previous one,
ALHA77219 (Agosto et al., 1980; Prinz et al.
1980).
ALHA81098 (60.9 g).?This sample consists
of two fragments (4 X 4 X 1.5; 4 X 3.4 X 1 cm)
that are similar to ALHA81059 in mineralogy,
texture, and weathering, and probably should be
paired with it.
Literature Cited
Agosto, W.N., R.H. Hewins, and R.S. Clarke, Jr.
1980. Allan Hills A77219, the First Antarctic Mesosi-
derite. In Proceedings of the Eleventh Lunar and
Planetary Science Conference, pages 1027-1045.
New York: Pergamon Press.
Clarke, R.S., Jr., and B. Mason
1982. A New Metal-Rich Mesosiderite from Antarctica,
RKPA79015. Memoirs of the National Institute of
Polar Research (Japan), special issue, 25:78-85.
Prinz, M., C.E. Nehru, and J.S. Delaney
1982. Reckling Peak A79015: An Unusual Mesosiderite.
In Lunar and Planetary Science XIII, page 631.
Houston: Lunar and Planetary Institute.
Prinz, M., C.E. Nehru, J.S. Delaney, G.E. Harlow, R.L.
Bedell
1980. Modal Studies of Mesosiderites and Related
Achondrites, Including the New Mesosiderite
ALHA 77219. In Proceedings of the Eleventh Lunar
and Planetary Science Conference, pages 1055-1071.
New York: Pergamon Press.
Petrology and Classification of
145 Small Meteorites from
the 1977 Allan Hills Collection
Susan G. McKinley and Klaus Keil
Introduction
We have studied 145 previously undescribed,
small meteorites weighing <150 g from the 1977
Allan Hills Antarctica collection. These meteor-
ites are part of the 350 samples collected by
scientists from the United States and Japan dur-
ing the 1977-1978 field season (Cassidy, 1980).
Because of their small sizes, these and other
specimens in the 1977 collection weighing <150
g were initially set aside and only later allocated
to us as a suite of 145 samples. The allocation
strategy was as follows: Except for a few mete-
orites that appeared unusual to the field party
and were allocated for preliminary description
and classification to B. Mason, each specimen
weighing <150>15g (although the largest spec-
imen weighed 174.5 g) was equally split between
the U.S. Antarctic Meteorite collection curated
at the Lyndon B. Johnson Space Center, Hous-
ton, Texas, and the Japanese Antarctic Meteorite
Collection at the National Institute of Polar Re-
search, Tokyo, Japan. Of each of these speci-
mens, we were allocated a few grams for our
studies. Meteorites weighing <15 grams were not
split but were divided in equal numbers between
the U.S. and Japanese collections. Each of those
meteorites remaining in the U.S. collection was
allocated to us in total for study and further
distribution to interested investigators.
Susan G. McKinley and Klaus Keil, Department of Geology and
Institute of Meteoritics, University of New Mexico, Albuquerque,
New Mexico 87131.
We carried out mineralogic and petrographic
studies of all 145 meteorites. In addition, we
initiated studies by others on selected specimens
from this suite. P. Signer and co-workers are
carrying out noble-gas measurements on four
type 3 ordinary chondrites, ALHA77011,
77013, 77176, and 77197, and the enstatite
chondrite ALHA77156. Thermoluminescence
sensitivity measurements were made by Sears and
Weeks (1983) on the same five meteorites. The
carbonaceous chondrite (C3O), ALHA77029,
was analyzed by INAA (Kallemeyn and Wasson,
1982) and a specimen of ALHA77011 (namely
ALHA77050) will be analyzed by J.T. Wasson
and co-workers. Several specimens of ALHA
77011 and a pyroxene-rich chondrule from the
same meteorite are being analyzed by R.N. Clay-
ton for oxygen isotopic compositions, and 23
equilibrated ordinary chondrites are being stud-
ied by J.R. Arnold and co-workers for tracks,
radionuclides (53Mn, 36C1, 10Be, 26A1), and rare
gases in a search for objects that may have
been in space as small meteoroids. Neon and
xenon isotopic compositions of graphite-magne-
tite inclusions in ALHA77011 (specimen ALHA
77050) were measured by Caffee et al. (1982).
We have also loaned polished thin sections of
various specimens to several investigators for op-
tical microscopy and electron microprobe stud-
ies.
Our mineralogic and petrographic studies
show that all 145 meteorites in our suite are
chondrites (Table 3). Of those, 120 are equili-
55
56 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
brated (i.e., petrologic types 4 to 6) ordinary
chondrites, with two belonging to the LL group,
16 to the L group, and 102 to the H group. The
remaining 25 specimens include 19 that are
paired with ALHA77011, an unusual L3 chon-
drite containing a graphite-magnetite matrix in
addition to the common silicate ("Huss") matrix
(Huss et al., 1981). Three specimens are un-
paired L3 chondrites (Table 4), two are paired
enstatite chondrites (EH4), and another is a car-
bonaceous chondrite (C3O).
Here we summarize the classification of all
meteorites in our suite and report in more detail
on the less common types, namely the carbona-
ceous chondrite, the four type 3 ordinary chon-
drites, and the enstatite chondrite. We conclude
that study of large suites of small Antarctic me-
teorites is exceedingly worthwhile and reward-
ing. Most specimens are relatively fresh and un-
weathered, and their large numbers increase the
likelihood of discovering new, unusual, and rare
meteorite types, such as the unique graphite-
magnetite bearing L3 ordinary chondrite and
the enstatite chondrite (the first from the Allan
Hills and only the fourth from Antarctica). Fur-
thermore, these small meteorites may be attrac-
tive for special studies, such as the search for
objects that travelled in space as small meteo-
roids. We therefore urge continued collection
and study of large suites of small Antarctic me-
teorites.
ACKNOWLEDGMENTS.?We thank the Antarc-
tic Meteorite Working Group for allocating to
us the 145 meteorites studied here; Robbie Score
(JSC) for valuable aid in preparing the specimens
for us; G. Gomez and Jackie Allen for preparing
polished thin sections; and E.R.D. Scott and GJ.
Taylor for valuable collaboration, assistance, and
discussions throughout the course of this project.
This work was supported in part by the National
Aeronautics and Space Administration, Grants
NGL32-004-064 and NAG-9-30 to K.K.
Method of Study
Each specimen weighing <15 g, which was
allocated to us in its entirety, was macroscopically
described before cutting. This description in-
cludes a sketch of the external shape of the
specimen and notes the external appearance of
the meteorite, including preservation of the fu-
sion crust, color, degree of weathering, veining,
etc. After cutting for preparation of polished thin
sections, detailed sketches of the cuts were made
and their weights were recorded. A similar brief
macroscopic description was also made of the
small aliquots we received of meteorites weighing
>15 g. Detailed information on their main
masses is not available from us but is available
from the Curatorial Office at the Johnson Space
Center. At least one polished thin section was
prepared of each specimen, using special proce-
dures (i.e., no water) in the preparation of sec-
tions of meteorites containing water-soluble
phases (e.g., the enstatite chondrite). Polished
thin sections were studied in the optical micro-
scope in transmitted and reflected light, and
olivine and pyroxene compositions of equili-
brated ordinary chondrites were determined
with an automated ARL EMX-SM electron mi-
croprobe. Electron microprobe analyses of these
and other phases were carried out using the
procedures of Bence and Albee (1968) and Keil
(1967), and standards and analytical conditions
employed were essentially those listed in Fodor
and Keil (1976). Analyzed olivine and pyroxene
grains were chosen at random, and ordinary
chondrites were then classified on the basis of
their ranges and mean olivine and pyroxene Com-
positions and their textural characteristics, using
a modified version of the Van Schmus and Wood
(1967) scheme (Gomes and Keil, 1980:31-32).
More detailed microscopic and electron micro-
probe studies were made on the carbonaceous
chondrite, the type 3 ordinary chondrites, and
the enstatite chondrite.
Chondrites
CLASS C3O
ALHA77029 (1.4 g).?This small stone meas-
ured 15x7x4 mm and was covered (except
on one flat side) by dark gray, frothy fusion crust.
No chondrules were visible on the surface, and
NUMBER 26 57
the only external weathering noted was in a small
pit in the fusion crust.
Microscopic and electron microprobe studies
(Scott, Taylor, et al., 1981) indicate that this
meteorite is an unpaired Ornans-type carbona-
ceous chondrite (C3O). It has the typical texture
of C3O meteorites and contains (in the termi-
nology of McSween, 1977) abundant chondrules
<0.5 mm in apparent diameter and lithic frag-
ments and inclusions embedded in a dark matrix
(Figure 57). These constituents occur in propor-
tions typical for C3O chondrites, except that the
matrix to chondrule ratio is the highest (0.79)
yet reported (Scott, Taylor, et al., 1981).
Matrix and mineral compositions are typical
of C3O chondrites. The matrix is high in FeO
and NiO, and olivine and pyroxene composi-
tional histograms obtained on randomly selected
grains have the characteristic means and broad
ranges of C3O chondrites (Scott, Taylor, et al.,
1981). The olivine histogram has no pronounced
peak and is similar to that of Ornans (Van
Schmus, 1969).
Based on compositional evidence (Scott, Tay-
lor, et al., 1981), we have classified this meteorite
as a moderately metamorphosed C3O chondrite
of stage II (McSween, 1977). The mean fayalite
composition (Fa2.s) is intermediate between the
least and most equilibrated C3O chondrites. Sim-
ilarly, kamacite has intermediate Cr, Co, and Ni
contents, resembling those of the C3O chon-
drites Felix and Lance (McSween, 1977).
CLASS EH4
ALHA77156 (17.7 g); ALHA77295 (141 g),
total weight 158.7 g. ALHA77156 is the first
enstatite chondrite recovered from the Allan
Hills; the second, ALHA81021, an EL6, was
found in 1981 (Schwartz and Mason, 1983). Two
others from Antarctica are Yamato 69001, an
EH4-5 (Okada, 1975) and RKPA80259, an EH5
(Score et al., 1982). We have paired ALHA-
77156 with ALHA77295, based on mineral
abundances and compositions. Following the rec-
ommendations of the Committee on Meteorite
Nomenclature of the Meteoritical Society (Gra-
ham, 1980), this chondrite should be referred to
as ALHA 77156.
ALHA77156 contains well-defined chon-
drules typical of type 4 chondrites (Figure 58).
Silicate phases include clinoenstatite and minor
olivine, albite, and silica. Kamacite, niningerite,
and zincian daubreelite are present in abun-
dances typical of EH4 chondrites. Troilite, per-
ryite, schreibersite, and oldhamite are more
abundant than in other EH4 chondrites. Acces-
sory djerfisherite, sphalerite, and weathered
caswellsilverite are also present.
Total Fe concentration (313 mg/g), calculated
from mineral compositions and modal abun-
dances, falls within the EH range (Sears, Kalle-
meyn, et al., 1982). Mineral compositions typi-
cally lie within the ranges of EH4 chondrites.
Those mineral compositions that are outside of
the range are usually close to the mineral com-
positions in Kota-Kota (EH4) (Keil, 1968). For
example, in both ALHA77156 and Kota-Kota,
the Ni content is higher in schreibersite and
lower in kamacite than the range for these min-
erals in other EH4 chondrites. Using the ninin-
gerite-oldhamite-troilite geothermometer of
Skinner and Luce (1971), the calculated equili-
bration temperatures for niningerite in
ALHA77156 and Kota-Kota agree well (475?C
and 485?C, respectively). These are the lowest
temperatures determined for EH4 chondrites.
Clinoenstatite luminesces in various shades and
intensities of red and blue under electron bom-
bardment. Random analyses of enstatite within
and outside of chondrules show that the bright
blue grains usually have very low (<0.1%) MnO
and Cr2C>3, whereas dull blue and red grains have
a broad range of MnO and Cr2O3 contents. Our
work on minor-element distributions in enstatite
of ALHA77156 and other enstatite chondrites
(McKinley et al., 1982, 1983) provides convinc-
ing evidence against the model of Leitch and
Smith (1980, 1981, 1982), in which enstatite
chondrites formed by collision of two planetesi-
mals, one consisting of red and the other of blue
luminescing enstatites, and mechanical aggrega-
tion of the debris.
58 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 57.?Photomicrograph of the C3O chondrite, ALHA77029, showing chondrules and
irregular inclusions in a dark matrix. Transmitted plane-polarized light. Scale =1.5 mm.
FIGURE 58.?Photomicrograph of the EH4 chondrite, ALHA77156 (paired specimen
ALHA77295,8), showing fine-grained opaque phases (light gray and white) and Fe.Ni metal-
sulfide aggregates. Reflected light. Scale = 2.7 mm.
NUMBER 26 59
CLASS L3
ALHA77011 (total weight 6338 g).?We have
paired 19 of the 145 small meteorites studied
here with 15 larger specimens from the 1977-
1978-1979 Allan Hills collection, based on the
presence of unique graphite-magnetite aggre-
gates (McKinley et al., 1981). Cassidy (1980) had
previously suggested that, on the basis of field
relationships, nine of the larger specimens may
be paired. ALHA77011 is one of the larger
specimens and is the lowest-numbered object of
the paired specimens. Thus, according to the
recommendation of the Committee on Meteorite
Nomenclature of the Meteoritical Society (Gra-
ham, 1980), this chondrite shower should gener-
ically be referred to as ALHA77011, although
this specimen is not part of the collection of small
meteorites described here.
ALHA77011 is a unique chondrite, character-
ized by the presence of abundant matrix and
inclusions (3.2 vol. %), consisting of aggregates
of micron-to-submicron-sized graphite and mag-
netite, in addition to the typical "Huss" silicate
matrix (Huss et al., 1981). This meteorite con-
tains graphite-magnetite in higher amounts than
most type 3 ordinary chondrites (which normally
have <0.1 vol. %) but in much lower proportions
than the type 3 ordinary chondrite clasts with
graphite-magnetite matrices (14-36 vol. %)
found in some regolith breccias (Scott, Rubin, et
al., 1981). In all other respects, ALHA77011 is
typical of type 3 ordinary chondrites. It has
sharply defined chondrules embedded into a ma-
trix consisting of about equal amounts of fine-
grained opaque and recrystallized silicate matrix
(Figure 59). Olivine compositions range from Fai
to Fa37 (percent mean deviation is 39) and low-
Ca pyroxene ranges from Fsi to Fs40 (percent
mean deviation is 56). The percent mean devia-
tion was calculated from FeO weight concentra-
tions in olivine and pyroxene. Metallic Fe,Ni has
significant amounts of Cr and Si and widely
varying Co contents, indicating that the meteor-
ite is one of the least-metamorphosed type 3
ordinary chondrites (Afiattalab and Wasson,
1980). Using the criteria of Sears, Grossman, et
al. (1982), we have classified ALHA77011 as a
petrologic type 3.2?0.2 (McKinley et al., 1981),
whereas Sears, Grossman et al. (1982) classified
it as a petrologic type 3.5? 0.1. Additional
mineralogic-petrographic studies of the meteor-
ite have been carried out by Ikeda et al. (1981),
Fujimaki et al. (1981), and Nagahara (1981).
Classification of ALHA77011 as an L-group
chondrite was originally proposed by King et al.
(1980), based on petrographic studies. This clas-
sification was confirmed by the bulk analysis of
Jarosewich (1980), which yielded total Fe of
20.77 wt.% and an Fe/SiO2 weight ratio of 0.55,
well within the L-group range. The Ni/Mg
(0.086), S/Mg (0.15), and Fe/Mg (1.52) ratios
also fall within the L fields of Jarosewich and
Dodd(1981).
ALHA77013 (23.0 g).?This meteorite con-
tains very well-defined, densely packed chon-
drules in a matrix of recrystallized Huss silicate
matrix and fine-grained silicates (Figure 60).
Typical chondrule types are present, including a
barred olivine chondrule with interstitial glass.
Olivine composition ranges from Fa9.o to Fa27.e
(mean Fai8.7), with a standard deviation of the
analyses (mole % Fa) of 3.8 and a percent mean
deviation of 16.6. Pyroxene ranges from Fs22to
Fs35 (mean FS13.1), with a standard deviation of
the analyses (mole % Fs) of 7.9 and a percent
mean deviation of 47.3. We classify ALHA77013
as an L3 chondrite, based on its low metallic
Fe,Ni content of 3 vol. % and its texture. The
olivine and pyroxene compositions (Figure 61)
are less conclusive and trend more towards the
H group. However, these data suggest that the
meteorite is not paired with any other from
Victoria Land.
ALHA77013 has been classified as a petrol-
ogic type 3.5, based on thermoluminescence sen-
sitivity (Sears and Weeks, 1983). The coefficient
of variation of Fa is 20.5, which is within the
range for type 3.7 (Sears, Grossman, etal., 1982).
ALHA77176 (54.4 g).?This unpaired mete-
orite contains very well-defined chondrules in a
matrix of opaque and recrystallized Huss silicate
matrix (Figure 62). A few large lithic inclusions
FIGURE 59.?Photomicrograph of the L3 chondrite, ALHA77O11 (paired specimen
ALHA77052) showing abundant, well-defined chondrules. Transmitted plane polarized light.
Scale = 2.5 mm.
:%,.. '?**- '-.;,:' -y.mr ' "? v?
?* -??- ?.-
FIGURE 60.?Photomicrograph of the L3 chondrite, ALHA77013, showing abundant, well-
defined chondrules. Transmitted plane-polarized light. Scale = 3.0 mm.
NUMBER 26 61
are present and the chondrules are commonly
irregular in shape. Typical chondrule types are
present and clear glass is common in some. Troil-
ite occurs as shock-melted, "fizzed" intergrowths
with metallic Fe,Ni and as individual polycrystal-
line grains.
Olivine and pyroxene in this meteorite are
more variable in composition (Figure 61) than in
any other Antarctic ordinary chondrite, with the
possible exception of ALHA76004 (Scott, this
volume), indicating that it is less equilibrated.
Olivine ranges from Fao.3 to Fa33.5 (mean Fa 12.4),
with a standard deviation of the analyses (mole
% Fa) of 8.3 and a percent mean deviation of
54.3. Pyroxene ranges from Fsi.8 to Fs36.7 (mean
Fsi2.2)> with a standard deviation of the analyses
(mole % Fs) of 8.9 and a percent mean deviation
of 61.2. We have classified the meteorite as an L
0
OLIVINE
ALHA770I3
H L
LOW-Ca PYROXENE
ALHA770I3
H L LL
10 20
Mole% Fa
20
Mole% Fs
FIGURE 61.?Histograms of electron microprobe analyses of randomly selected olivines (in
mole % fayalite), and low-Ca pyroxenes (in mole % ferrosilite), in three L3 chondrites from
the Allan Hills. Also given are the number of analyses (N) and their standard deviation (a).
Compositional ranges for equilibrated H, L, and LL group chondrites are from Gomes and
Keil(1980).
FIGURE 62.?Photomicrograph of the L3 chondrite, ALHA77176, showing well-defined
chondrules, a large broken chondrule, and an inclusion. Transmitted plane-polarized light.
Scale = 2.0 mm.
FIGURE 63.?Photomicrograph of the L3 chondrite, ALHA77197, showing abundant, well-
defined chondrules. Transmitted plane-polarized light. Scale = 3.0 mm.
NUMBER 26 63
group chondrite, based on its low metallic Fe,Ni
content (5 vol. %), and as a petrologic type 3,
based on its texture and variable olivine compo-
sitions. Olivine and low-Ca pyroxene have sig-
nificantly higher mean MgO and CaO contents
than ALHA76004 (see Scott, this volume), indi-
cating less equilibration. ALHA77176 has been
classified as a petrologic type 3.2, based on ther-
moluminescence sensitivity (Sears and Weeks,
1983). The coefficient of variation for Fa in
olivine is 67, which indicates a petrologic type
<3.4 (Sears, Grossman, et al., 1982).
ALHA77197 (20.3 g).?This meteorite con-
tains very well-defined chondrules in a matrix of
fine-grained silicates and recrystallized Huss sili-
cate matrix (Figure 63). Typical chondrule types
are present, including two with pinkish brown
glass.
Olivine composition ranges from Fai0.4 to
Fa27.4 (mean Fa24.4), with a standard deviation of
the analyses (mole % Fa) of 3.0 and a percent
mean deviation of 6.2. Only four of 67 olivine
analyses fall outside the range for olivine of L
group chondrites (Figure 61); two of these are
from the same grain. Pyroxene ranges from Fs40
to Fs2i.o, with a standard deviation of the analyses
(mole % Fs) of 5.1 and a percent mean deviation
of 30.7. We therefore classify ALHA77197 as
an L3 chondrite based on low metallic Fe,Ni
content, olivine and pyroxene composition, and
texture. The meteorite was classified as a petrol-
ogic type 3.6, based on thermoluminescence sen-
sitivity (Sears and Weeks, 1983). This classifica-
tion may be somewhat too low in petrologic
grade; the coefficient of variation of Fa is 12.3
%, which falls within the range (10-20%) for
petrologic type 3.8 (Sears, Grossman, et al.,
1982).
ALHA77197 is not paired with the other
eight L3 chondrites from Victoria Land. It
is closest in composition to ALHA79022
and RKPA80256. However, the olivine in
ALHA77197 is more magnesian than that in
ALHA79022 and pyroxene is less variable in
composition than that in RKPA80256 (Scott, this
volume). Although there are no mineral compo-
sitional data available on ALHA77215, the brec-
ciated texture of this regolith breccia (Score,
personal communication, 1983) rules out pairing
with ALHA77197.
Equilibrated Ordinary Chondrites
(Petrologic Types 4 to 6)
The classifications of 120 equilibrated ordi-
nary chondrites (petrologic types 4 to 6) are given
in Table 3, together with those of the 22 type 3
ordinary chondrites. The criteria we used in
classifying these chondrites are those proposed
by Van Schmus and Wood (1967), as modified
by Gomes and Keil (1980:31-32). The petrologic
characteristics of ordinary chondrites form a con-
tinuum from types 3 to 6; thus pigeonholing
chondrites into petrologic types is always some-
what arbitrary, particularly for the higher petro-
logic types. The main diagnostic criteria we used
in classifying ordinary chondrites into petrologic
types are as follows: type 3, >5 percent mean
deviation in the FeO content of olivine; type 4,
<5 percent mean deviation in the FeO content
of olivine and >20 percent of the total pyroxene
is clinopyroxene; type 5, <20 percent of the total
pyroxene is clinopyroxene, and plagioclase is
common, with grains <50 /im across; and type 6,
plagioclase is abundant and grains are >50 pm
across.
Discussion
The main motivation for studying this large
collection of small meteorites stems from our
previous experience with large suites of ran-
domly collected, small rake samples of lunar
rocks (e.g., Dowty, Prinz, et al., 1973; Dowty,
Conrad et al., 1973; Warner et al., 1975). Our
experience is that systematic study of such suites
increases the probability of discovering new and
rare rock types and that it facilitates comparison
of rocks via large data bases obtained in one
laboratory. Our optimism was justified. We iden-
tified a new meteorite type, ALHA77011, a type
3 ordinary chondrite with a graphite-magnetite
64 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
matrix, in addition to the common Huss silicate
matrix. Comparison of specimens in this suite
enabled us to pair 19 specimens of ALHA77011
from among the 145 meteorites studied here
with 15 larger specimens from the 1977-1978-
1979 Allan Hills collections. We further discov-
ered a number of rare meteorites, such as the
C3O carbonaceous chondrite (ALHA77029),
two paired specimens of an EH4 enstatite chon-
drite (ALHA77156, ALHA77295), and three
unpaired petrologic type 3 ordinary chondrites
(ALHA77013, ALHA77176, ALHA77197).
Concerns that these small meteorites would be
too weathered for scientific study proved to be
largely unfounded. Comparison of paired small
and large members of a fall indicates that the
small objects are not significantly more weath-
ered than the larger ones, at least not in case of
the meteorites we studied. Thus, the success in
discovering new and rare meteorites in this suite
strongly argues for the need to continue to col-
lect very small meteorites in Antarctica, to care-
fully document their field relationships, and to
make them available for study.
In Table 4 we summarize the classification of
all 142 ordinary chondrites (petrologic types 3
to 6) studied here. We compare this suite with
the classifications of mostly larger types 3 to 6
ordinary chondrites from the 1976-1979 collec-
tions from the Allan Hills, Antarctica (Score et
al., 1981), the ordinary chondrite falls and finds
(Motylewski, 1978), and falls only (Wasson,
1974) from the rest of the world. The purpose
of this comparison is to see if there are any
similarities or differences in classifications of
small ordinary chondrites in the 1977 Allan Hills
collection when compared to mostly larger me-
teorites from the same location in Antarctica and
from locations around the world, both for falls
and finds together and for observed falls only.
Such a comparison may allow us to make infer-
ences as to the arrival and collection of generally
rather recent arrivals of meteorites to Earth (e.g.,
as represented among falls and finds from the
rest of the world), with the generally older me-
teorites (in terms of terrestrial residence time),
Nomenclature for Shock Facies
(from Dodd and Jarosewich, 1979:340)
a = Olivine fractured; plagioclase at least 50% un-
deformed; melt pockets not present.
b = Olivine fractured and with undulose extinc-
tion; plagioclase at least 50% undeformed; melt pock-
ets not present.
c = Olivine fractured and with undulose extinction;
plagioclase at least 50% deformed, but maskelynite
and melt pockets absent.
d = Olivine fractured and with mosaic extinction;
plagioclase entirely deformed and/or maskelynite;
melt pockets present.
preserved in the deep-freeze of the Antarctic ice
(Evans et al., 1982). It should be noted at the
outset that such comparisons are considerably
affected by many uncertainties due to serious
sampling errors and statistical biases. Uncertain-
ties result from biases in the removal of meteor-
ites from their parent bodies, orbital considera-
tions, possible selection effects during atmos-
pheric entry and survival on the ground, pairing
of Antarctic finds, and relatively small numbers
of meteorites available for comparison. It would
appear, however, that the falls summarized by
Wasson (1974) would most closely represent the
distribution of more recent arrivals to Earth of
ordinary chondrites. Furthermore, the ordinary
chondrite types represented among the Allan
Hills collections (Score et al., 1981) might be
expected to be similar to those in the suite of
142 ordinary chondrites studied here. However,
as pointed out above, extreme caution must be
exercised in such comparisons. Nevertheless,
some useful information appears to emerge from
the comparison, which is summarized here.
First, the percentage of H5 chondrites in our
suite (83%) is much larger than that among the
observed falls (47%; Wasson, 1974). Since there
are at least 17 paired specimens among the H5
chondrites {Antarctic Meteorite Newsletter, 1981) of
Score et al. (1981), we conclude that probably
many of our H5 chondrites are also paired, thus
explaining their preponderance over those
among observed falls.
NUMBER 26 65
TABLE 3.?Characterization of small meteorites from the 1977-1978 Allan Hills collection
(n.d. = no data; A = minor; B = moderate; C = severe).
ALHA
77007
77008
77013
77016
77017
77018
77019
77022
77023
77026
77027
77029
77031*
77034*
77036*
77038
77039
77041
77042
77043*
77045
77046
77047*
77049*
77050*
77051
77052*
77054
77056
77058
77060
77063
77066
77069
77070
77073
77076
77078
77079
77082
77084
77085
77087
77089
77091
77092
77094
77096
Weight
(g)
99.3
93.0
23.0
78.3
77.9
51.8
59.8
16.0
21.4
20.3
3.7
1.4
0.5
1.8
8.5
18.8
8.2
16.6
20.4
11.4
17.9
7.6
20.4
7.3
84.2
15.0
112
10.4
12.3
3.7
64.4
2.9
4.9
0.8
18.4
10.1
1.7
7.8
7.8
12.0
44.1
45.9
30.7
7.8
4.2
45.0
6.6
2.5
Class
and
type
H5
L6
L3
H5
H5
H5
L6
H5
H5
L6
L6
C3O
L3
L3
L3
H5
H5
LL6
H5
L3
H5
H6
L3
L3
L3
H5
L3
H5
H4
H5
LL5
H5
H5
L6
H5
H5
H5
H5
H5
H5
H5
H5
H5
L6
H5
H5
H5
H5
Olivine
(mole % Fa)
19.1
24.6
9-28
18.6
18.8
19.0
24.9
19.1
19.1
24.3
25.0
23
n.d.
n.d.
n.d.
19.0
18.5
30.7
19.0
1-37
18.7
19.0
n.d.
n.d.
n.d.
18.8
n.d.
18.5
18.8
18.8
28.1
18.0
19.0
25.4
18.4
18.8
19.5
19.5
18.2
19.3
18.8
18.8
19.0
25.5
18.9
18.5
18.5
18.7
Pyroxene
(mole % Fs)
16.7
20.6
1-35
17.1
16.3
17.0
21.4
17.0
16.8
20.7
21.5
2.6
n.d.
n.d.
n.d.
17.1
16.3
25.1
16.0
1-28
17.0
16.7
n.d.
n.d.
n.d.
16.5
n.d.
16.9
16.3
16.1
23.2
16.8
17.4
21.4
16.8
17.7
16.1
16.7
15.8
16.5
16.8
17.6
16.7
21.4
16.1
16.5
16.2
17.1
Degree
of
weathering
B
A
B
B
B
B/C
B/C
A
B
B/C
B/C
A/B
B/C
B/C
B
A/B
A/B
A
A/B
B/C
A
A/B
C
B/C
B/C
A
B/C
B
A/B
B
A
B
A
B/C
B
A/B
B
B
A
A/B
A/B
B
B
B
B/C
A
B
A
Shock
faciesf
a
c
b
c
c
b
d
c
c
b
d
a
b
b
b
c
c
b
b
b
b
c
b
b
b
b
b
c
b
b
b
c
c
d
b
b
b
b
b
c
b
b
b
b
a
b
b
b
?f Nomenclature following Dodd and Jarosewich (1979:340); see accompanying box on p. 64.
66 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE 3.?Continued.
ALHA
77098
77100
77101
77104
77106
77108
77111
77112
77113
77114
77115*
77117
77120
77122
77125
77126
77127
77129
77130
77131
77132
77133
77134
77136
77138
77139
77142
77143
77146
77147
77149
77151
77152
77153
77156
77157
77158
77159
77161
77162
77163*
77166*
77168
77170*
77171
77173
77174
77175*
77176
Weight
(g)
8.0
8.5
3.8
6.3
7.8
0.7
52.3
21.7
2.0
44.5
154
20.8
3.9
4.6
18.7
25.2
3.8
1.7
24.8
25.9
115
18.7
19.1
3.6
2.1
65.9
3.1
39.0
18.2
18.7
25.6
16.9
17.8
12.0
17.7
88.3
19.9
17.0
6.1
29.0
24.3
140
24.7
12.2
23.8
25.8
32.4
23.3
54.4
Class
and
type
H5
H5
H5
H5
H5
H5
H6
H5
H5
H5
L3
L5
H5
H5
H5
H5
L5
H5
H5
H6
H5
H6
H6
H5
H5
H5
H5
H5
H6
H6
H6
H5
H5
H5
EH4
H6
H5
L6
H5
L6
L3
L3
H5
L3
H5
H5
H5
L3
L3
Olivine
(mole % Fa)
18.7
19.2
18.6
18.9
18.8
18.5
19.0
18.7
18.7
19.6
n.d.
24.4
18.5
19.1
17.2
18.3
25.0
18.9
18.9
19.2
19.0
19.0
18.9
19.1
19.2
18.6
18.9
18.7
18.9
19.0
19.1
18.9
18.7
19.2
0.8
18.6
18.9
24.4
19.3
25.3
n.d.
n.d.
19.0
n.d.
18.9
19.1
18.3
n.d.
0.3-34
Pyroxene
(mole % Fs)
16.7
16.4
17.0
16.9
16.5
15.9
16.6
16.7
17.2
17.2
n.d.
21.0
16.0
16.8
15.5
16.2
21.1
16.6
16.5
16.8
16.9
17.0
16.7
16.4
17.0
16.4
17.1
16.2
16.9
16.6
16.9
16.4
16.9
16.7
1.5
15.7
16.9
20.8
17.1
20.9
n.d.
n.d.
16.5
n.d.
17.0
17.0
16.0
n.d.
1-37
Degree
of
weathering
B
A/B
B
A
A/B
A/B
A/B
A
B
B
B/C
A/B
A/B
B
A/B
A/B
B
B
A
A/B
A/B
A
A
A/B
A
A/B
A/B
A/B
A/B
A/B
A/B
A
A
A
A
B
A/B
A/B
B
A
B/C
C
B
B/C
A/B
B
A
B/C
B
Shock
facies
b
b
b
b
c
a
a
a
a
b
b
c
a
b
a
a
d
a
a
b
a
a
c
a
a
b
b
b
a
b
a
a
b
b
b
b
b
c
b
d
b
b
b
b
a
a
b
b
b
TABLE 3.?Continued.
ALHA
77178*
77181
77184
77185*
77186
77187
77188
77193
77195
77197
77198
77200
77201
77202
77205
77207
77209
77211*
77212
77213
77218
77220
77222
77227
77228
77235
77237
77239
77240
77241*
77242
77244*
77245
77246
77247
77248
77251
77253
77265
77266
77267
77275
77279
77291
77293
77295**
77301
77303*
Weight
(g)
5.7
33.0
128
28.0
122
52.2
109
6.7
4.7
20.3
7.3
0.9
15.0
2.7
3.1
4.9
31.8
26.7
16.8
8.4
45.1
69.1
125
16.0
19.3
4.9
4.1
19.0
25.1
144
56.5
39.5
33.4
41.6
44.2
96.1
68.8
23.6
18.3
108
103
24.9
174
5.8
110
141
55.0
78.6
Class
and
type
L3
H5
H5
L3
H5
H5
H5
H5
H5
L3
L6
H6
H5
H5
H5
H5
H6
L3
H6
H5
L5
H5
H4
H5
H5
H5
H5
H6
H5
L3
H5
L3
H5
H6
H5
H6
L6
H5
H5
H5
L5
H5
H5
H5
L6
EH4
L6
L3
Olivine
(mole % Fa)
1-36
20.0
17.8
n.d.
18.8
18.1
18.1
19.0
18.9
10-27
24.4
19.7
18.8
18.6
18.8
17.8
18.8
n.d.
18.9
18.6
23.4
17.7
18.0
18.9
18.5
18.9
18.5
18.7
18.8
n.d.
18.8
n.d.
19.2
19.2
18.8
18.7
25.0
19.2
17.6
19.6
24.7
18.3
18.8
18.9
24.7
0.8
24.9
n.d.
Pyroxene
(mole % Fs)
2-40
17.3
15.9
n.d.
16.0
16.3
16.1
15.7
16.4
4-21
20.6
17.6
15.3
16.6
16.7
16.7
16.4
n.d.
17.0
16.5
19.1
16.0
15.3
16.6
16.3
16.7
15.8
15.9
16.0
n.d.
16.2
n.d.
17.2
16.5
16.4
16.7
21.3
16.9
15.9
17.7
20.9
15.6
17.1
15.9
20.9
1.7
20.9
n.d.
Degree
of
weathering
B/C
B
B
A/B
A/B
A/B
A/B
A
A
A/B
B
C
A
B
B
A/B
B
B/C
A/B
A
A
B
A/B
A
B
A/B
A
B
A
C
B
B/C
A/B
B
A/B
B/C
B
A/B
B
B
A
A
A
A
B
A
A
B/C
Shock
facies
b
a
b
b
b
b
b
b
b
c
d
a
b
b
b
b
b
b
a
a
c
c
b
a
a
b
b
a
b
b
a
b
b
a
b
a
d
c
b
a
c
a
b
b
c
b
d
b
* Paired with A77011.
** Paired with A77156.
68 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE 4.?Classification of 142 small ordinary chondrites from the Allan Hills collection
compared to classifications of mostly larger specimens recovered from the Allan Hills in 1976,
1977, 1978, and 1979 (Score et al., 1981) as well as meteorite falls and finds (Motylewski,
1978) and falls only (Wasson, 1974) in the rest of the world.
Class
H3
H4
H5
H6
Total H
L3
L4
L5
L6
Total L
LL3
LL4
LL5
LL6
Total LL
Total H
Total L
Total LL
Total ordinary
chondrites
This paper
No.
0
2
85
15
102
22
0
4
12
38
0
0
1
1
2
102
38
2
142
%
0
2
83
15
100
58
0
10
32
100
0
0
50
50
100
72
27
1
100
Score et al.
No.
4
28
68
30
130
19
1
3
54
77
4
0
3
2
9
130
77
9
216
(1981)
%
3
22
52
23
100
25
1
4
70
100
45
0
33
22
100
60
36
4
100
Motylewski*
No.
11
86
174
86
357
12
30
78
262
382
6
1
12
30
49
357
382
49
788
(1978)
%
3
24
49
24
100
3
8
20
69
100
12
2
25
61
100
45
49
6
100
Wasson (1974)
No.
6
23
53
32
114
9
11
28
117
165
6
1
7
20
34
114
165
34
313
%
5
20
47
28
100
5
7
17
71
100
18
3
20
59
100
36
53
11
100
* Approximately 2% of these chondrites are from Antarctica.
Second, the percentage of H4 chondrites in
our collection (2%) is much lower than in the
collection of Score et al. (1981). At least ten of
the latter appear to be paired (Antarctic Meteorite
Newsletter, 1981), but this is still considerably
higher than the proportion in our suite. It should
be noted that the paired specimens of Score et
al. (1981) all weigh more than 1 kg, whereas ours
weigh less than 150 g. One is tempted to specu-
late that the shower of the paired H4 chondrites
in the Score et al. (1981) suite yielded predomi-
nately large specimens, whereas we studied only
small objects. However, Cassidy (1980) states that
some of their paired H4 specimens were taken
from an area where the smaller objects were
removed by wind on the ground.
Third, the proportion of L3 chondrites in our
and the Score et al. (1981) suite (58% and 25%
of L chondrites, respectively) is biased by the
large ALHA77011 shower when compared to
falls (5%; Wasson, 1974) and falls and finds (3%;
Motylewski, 1978). Our suite contains 19 and
the Score et al. (1981) 15 paired specimens of
the ALHA77011 L3 shower. Hence, the per-
centage of L6 chondrites in our L suite (32%) is
artificially low when compared to observed falls
(71%). The percentage of L6 chondrites in the
Score et al. (1981) L suite (70%) is high in spite
of the large number of paired L3 chondrites
because at least 20 of the L6 chondrites are also
paired (Antarctic Meteorite Newsletter, 1981). Re-
calculation, taking into account pairings, would
result in approximately 60% L6 chondrites in
our L suite and 80% in that of Score et al. (1981),
NUMBER 26 69
more in keeping with observed falls (Wasson,
1974).
Fourth, when considering the percentage of
H, L, and LL group chondrites, it is apparent
that H chondrites dominate over L and LL chon-
drites in our and the Score et al. (1981) suite.
This dominance remains even when taking into
account the pairings discussed above. This is
contrasted by a domination of L over H chon-
drites and a higher proportion of LL chondrites
among falls (Wasson, 1974) and less so, falls and
finds (Motylewski, 1978) in the rest of the world.
We conclude that among the generally recent
arrivals to the Earth, as represented by observed
falls and finds from the rest of the world, L and
LL chondrites occur in much greater proportion
than among the generally earlier arrivals repre-
sented by the Antarctic chondrites.
Summary
Mineralogic and petrographic study of 145
previously undescribed, small meteorites weigh-
ing <150 g from the 1977 Allan Hills, Antarc-
tica, collection, indicates that 120 are equili-
brated (petrologic types 4 to 6) H(102), L(16),
and LL(2) group chondrites. The remaining
25 specimens include 19 that are paired with
the graphite-magnetite-bearing L3 chondrite
ALHA77011; three unpaired L3 ordinary chon-
drites; two paired specimens of an enstatite chon-
drite (EH4); and one carbonaceous chondrite
(C3O). The discovery of new and rare meteorites
that are generally no more severely weathered
than large meteorites strongly argues for contin-
ued collection of small meteorites in Antarctica.
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Keil, K.
1967. The Electron Microprobe X-Ray Analyzer and Its
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1968. Chemical and Mineralogical Relationships among
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King, T.V.V., R. Score, E.M. Gabel, and B. Mason
1980. Meteorite Descriptions. In U.B. Marvin and B.
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Leitch, C.A., andJ.V. Smith
1980. Two Types of Clinoenstatite in Indarch Enstatite
Chondrite. Nature, 283:60-61.
1981. Mechanical Aggregation of Enstatite Chondrites
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1982. Petrography, Mineral Chemistry and Origin of
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McKinley, S.G., K. Keil, and E.R.D. Scott
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McKinley, S.G., E.R.D. Scott, and K. Keil
1983. Chondrules in Enstatite Chondrites?Nature and
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McKinley, S.G., E.R.D. Scott, GJ. Taylor, and K. Keil
1981. A Unique Type 3 Ordinary Chondrite Contain-
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McSween, H.Y.Jr.
1977. Carbonaceous Chondrites of the Ornans Type: A
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Motylewski, K.
1978. The Revised Cambridge Chondrite Compendium. Cam-
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Nagahara, H.
1981. Petrology of Chondrules in ALH-77015 (L3)
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1975. Petrological Studies of the Yamato Meteorites,
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1983. Antarctic Meteorite Descriptions 1981. Antarctic
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Bogard, and E.M. Gabel
1981. Antarctic Meteorite Descriptions 1976-1977?
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Scott, E.R.D., A.E. Rubin, GJ. Taylor, and K. Keil
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McKinley, and H.Y. McSween, Jr.
1981. Three CO3 Chondrites from Antarctica?Com-
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1982. The Compositional Classification of Chondrites,
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Cosmochimka Ada, 46:597-608.
Sears, D.W.G., and K.S. Weeks
1983. Thermoluminescence Sensitivity of Sixteen Type
3 Ordinary Chondrites. In Lunar and Planetary
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Science XIV, pages 682-683. Houston: Lunar and
Planetary Institute.
Skinner, B.J., and F.D. Luce
1971. Solid Solutions of the Type (Ca,Mg,Mn,Fe)S and
Their Use as Geothermometers for the Enstatite
Chondrites. American Mineralogist, 56:1269-1296.
Van Schmus, W.R.
1969. Mineralogy, Petrology, and Classification of Type
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Van Schmus, W.R., and J.A. Wood
1967. A Chemical-Petrologic Classification for the
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Warner, R.D., K. Keil, M. Prinz, J.C. Laul, A.V. Murali,
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1975. Mineralogy, Petrology, and Chemistry of Mare
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Wasson, J.T.
1974. Meteorites?Classification and Properties. 316 pages.
Heidelberg: Springer-Verlag.
Classification, Metamorphism, and Brecciation
of Type 3 Chondrites from Antarctica
Edward R.D. Scott
Introduction
Japanese and United States expeditions to Ant-
arctica are known to have recovered 60 speci-
mens, which probably represent about 21 differ-
ent type 3 chondrites. About 59 type 3 chon-
drites have been recovered from outside Antarc-
tica and over two-thirds of these are poorly de-
scribed or inaccessible. Thus the Antarctic spec-
imens represent a substantial addition to our
supply of type 3 chondrites?the least metamor-
phosed or altered samples of early solar system
materials. Interestingly, the ratio of ordinary to
carbonaceous type 3 chondrites (Table 5) is much
higher for Antarctic (4.2) than non-Antarctic
meteorites (2.8) and for meteorite falls (2.1).
Reid (1982) has observed similar disparities be-
tween Antarctic and non-Antarctic achondrites
and speculates that the flux of meteorites reach-
ing the earth may have changed with time, as the
Antarctic samples have longer mean terrestrial
ages (Evans et al., 1982).
This paper describes the 21 type 3 chondrites
that have been identified to date among the
1969-1980 collections, and reviews chemical
and petrologic studies relevant to their classifi-
cation into groups and subtypes. I present new
electron-probe analyses of silicates in 11 type 3
and 4 ordinary chondrites, which suggest that
several should be reclassified. Seven of these
Edward R.D. Scott, Department of Geology and Institute of
Meteoritics, University of New Mexico, Albuquerque, New
Mexico ?7131.
chondrites contain both equilibrated and une-
quilibrated chondrules, indicating that meta-
morphism must have preceded lithification of
these rocks. I conclude that most type 3 chon-
drites are probably breccias of materials with
differing metamorphic histories.
TABLE 5.?Approximate numbers of Antarctic and non-
Antarctic type 3 chondrites described before 1983.
Class
ORDINARY
H3
L3
LL3
CARBONACEOUS
C3O
C3V
OTHER
Total
Antarctic
5
9
3
2
1
1
21
Non-Antarctic
17
13
11
6
9
3
59
ACKNOWLEDGMENTS.?I thank A. Bischoff,
A.E. Rubin, and C. Williams for technical assist-
ance, K. Keil, S.G. McKinley, D.W. Sears, and
GJ. Taylor for useful advice and data, and the
Antarctic Meteorite Working Group (USA) and
the National Institute of Polar Research (Japan)
for the loan of samples. This work was supported
in part by NASA grant NGL 32-004-064 to K.
Keil.
Techniques
Randomly chosen olivine and low-Ca pyroxene
grains in 11 type 3 and 4 chondrites were ana-
73
74 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
lyzed in the electron probe for Fe, Mg, Si, and
Ca using crystal spectrometers (Fodor and Keil,
1976). In addition 4 to 10 olivine grains and,
where possible, an equal number of pyroxene
grains were analyzed in each of 109 chondrules
in 8 of these chondrites. Chondrules with heter-
ogeneous silicates were analyzed more thor-
oughly. These analyses were not made randomly;
cores and rims of grains of various sizes both
near the center and rim of chondrules were
analyzed.
Bulk chemical data for major and minor ele-
ments are available for only 7 of the 24 meteor-
ites listed in Table 6. Thus, classifications are
based very largely on abundances of metallic Fe,
Ni and olivine compositions. Dodd et al. (1967)
showed that the most unequilibrated ordinary
chondrites do not have peaks in histograms of
their olivine compositions. However, in cases
where 50% of the analyses lie in a narrow peak,
the olivine composition seems to be as accurate
a guide for classification as it is for types 4 to 6
chondrites. Jarosewich and Dodd (1981) identify
one such chondrite, Carraweena, for which
chemical and mineralogical data suggest differ-
ent classifications (LL and L, respectively).
Type 3 Carbonaceous Chondrites
Four type 3 carbonaceous chondrites are
known to have been recovered from Allan Hills
(ALH) and Reckling Peak (RKP), Antarctica:
ALHA77003, ALHA77029, ALHA77307, and
RKPA80241. Yamato 6903 is also discussed be-
low as it has been classified as a C3 chondrite
(Okada, 1975), although it is probably a type 4.
Data for these chondrites are summarized with
those for type 3 ordinary chondrites in Table 6.
Classifications, sample weights, and degrees of
weathering are taken from the catalogs of Yanai
(1979), King et al. (1980), and Score, Schwarz,
et al., (1982) and Score, King, et al. (1982),
except where noted. (The terms C3O and C3V
are used instead of CO3 and CV3 at the request
of the volume editors.)
ALHA77003.?This meteorite was described
as an H3 chondrite by King et al. (1980), but
reclassified as a C3 by Rhodes and Fulton (1981)
in accordance with their chemical data. Scott,
Taylor, et al. (1981) classified ALHA77003 as a
C3O chondrite on the basis of petrologic studies
and published chemical data. Ratios of Al/Si,
Mg/Si and Ca/Si from Jarosewich's (1980) anal-
ysis are appropriate for a CO chondrite, a classi-
fication with which Kallemeyn and Wasson
(1982a) concur. Its olivines vary widely in com-
position, 2-45 mole% fayalite, with about half
the analyses in the range Fa34 to Fa40. Thus it has
been metamorphosed more than Ornans but less
than Warrenton (Van Schmus, 1969) and is a
type II or III on McSween's (1977) metamorphic
classification. Analyses of the matrix in
ALHA77003 are reported by Ikeda et al. (1981)
and of microchondrules by Rubin et al. (1982).
ALHA77029.?This 1.4 g meteorite is one of
a suite of small samples described by McKinley
and Keil (herein, p. 56). It was classified by Scott,
Taylor, et al. (1981) as a C3O chondrite on the
basis of its mineralogy. Kallemeyn and Wasson
(1982b) analyzed a 72 mg sample by neutron
activation and agreed with its classficiation as a
CO chondrite. Its olivine compositions vary from
0.2 to 63% Fa with no prominent peak in a
histogram of 50 analyses, like those of Ornans
(Van Schmus, 1969). It is a metamorphic type II
on McSween's (1977) scale and is definitely not
paired with any other Antarctic chondrite so far
described.
ALHA77307.?This meteorite was classified
as a C3 chondrite by King et al. (1980). Scott,
Taylor, et al. (1981) likened 77307 to Kainsaz, a
very unmetamorphosed C3O, from petrologic
studies. Biswas et al. (1981) listed 77307 as a
C3V chondrite, as its Cd concentration is typical
of C3V chondrites but 30 times higher than any
C3O (Takahashi et al., 1978). Kallemeyn and
Wasson (1982a) conclude that the bulk chemistry
of 77307 partly resembles that of CM and CO
chondrites, but they classify it as a unique car-
bonaceous chondrite. Nagahara and Kushiro
(1982) studied the relationships between chon-
drules, inclusions, and isolated olivines in this
NUMBER 26 75
meteorite. They identified a sequence of aggre-
gates and chondrules that increased in grain size
and attribute their textural changes to heating
below the liquidus. Moore et al. (1981) also ana-
lyzed 77307 and identified traces of amino acids.
RKPA8024L?This 0.6 g meteorite is, sur-
prisingly, the only known C3V chondrite from
Antarctica. (ALHA80133 was tentatively classi-
fied as a C3V chondrite by Score, Schwarz, et al.
(1982), but is here paired with ALHA77011
(L3); see Table 8.)
Yamato 6903.?Okada (1975) and Okada et
al. (1975) have provided extensive petrologic and
chemical data for this meteorite under the name
"Yamato (c)," and classified it as a type III car-
bonaceous chondrite. McSween (1979) lists it as
a C3V chondrite, although the published silicate
analyses and textural descriptions suggest it may
be a type 4 or 5 chondrite. Additional evidence
for a higher petrologic grade is provided by
Clayton et al. (1979), who found some equilibra-
tion of oxygen isotopes between minerals, like
that in Karoonda, which is a type 5 (McSween,
1979). The bulk Al/Si, Mg/Si, and Ca/Si ratios
TABLE 6.?Type 3 chondrites from Antarctica and their properties (anom. = anomalous; br =
breccia containing more equilibrated clasts or regions; rbr = regolith breccia containing solar-
wind noble gases and equilibrated clasts).
Name
ALHA76004
ALHA77003
ALHA77011
ALHA77O13
ALHA77029
ALHA77176
ALHA77197
ALHA772151
ALHA77278
ALHA77299
ALHA77304
ALHA773O7
ALHA78084
ALHA79003
ALHA79022
OTTA80301
RKPA79008
RKPA80205
RKPA80207
RKPA80241
RKPA80256
Yamato 6903
Yamato 74191
Yamato 75028
Class
and
type
LL3a
C3Ob
L3C
L3d
C3Ob
L3d
L3d
L3-rbrc
LL3f
H3-br
L4n
C3 anom.
H4n
LL3h
L3-brn
H3
L3
H3
H3n
C3V
L3
C4??n
L3
H3-rbr
Subtype1"
3.3
3.4-3.5
3.5
3.2
3.6
3.8
3.6
3.7
3.7?
3.9
3.4h
3.7?
3.7
3.7
3.7
3.2?
3.6?
3.6
Original
weight
(g)
305a
779.6
6338C
23.0
1.4
54.4
20.3
3046
312.9
260.7
650.4
181.3
14280
5.1
31.4
35.5
73.0
53.8
17.7
0.6
153.2
150
1091.6
6100
Degree
of
weathering
A
A
C
Bd
A/Bd
Bd
A/Bd
B
A
A
B
A
B/C
B
A/B
B/C
B
B
C
B
B
An
Olivine composition
Mean
%Fa
17n
25b
17C
19d
23b
12d
24d
24e
22R
l7n
25.5n
13b
18.7n
26h
23.6n
18.2"
23n
16n
19n
3j
23.8"
301
21n
19.4k
a/mean
%
56n
52b
48C
20d
83b
67d
12d
44g
33"
4"
130b
1.7"
43h
4n
6n
18n
20n
22"
5n
lj
23n
' ALHA77216, 77217, and 77252 are paired with ALHA77215.
REFERENCES (for sources of unreferenced data, see p. 73):a Olsen et al., 1978; b Scott,Taylor,
et al., 1981; ' McKinley et al., 1981, and Table 8 herein; d McKinley and Keil, herein; e Score,
1980; ' McSween and Wilkening, 1980; g A. Okada, personal communication; h Scott, Taylor,
Maggiore, 1982; ' Score, Schwarz, et al., 1982;j Okada, 1975, and Okada et al., 1975; k Yanai
et al., 1978;'" Sears et al., 1980, 1982, and Sears and Weeks, 1983; n this work.
76 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
for Yamato 6903 (Shima and Shima, 1975) are
all in the range of carbonaceous chondrites (Was-
son, 1974). Ca/Si and Ca/Mn ratios are consist-
ent with those of CV chondrites (Kallemeyn and
Wasson, 1981), but Al/Si and Al/Mn appear to
be too low. Further studies are obviously needed
to establish its classification.
Type 3 Ordinary Chondrites
Seventeen Antarctic type 3 ordinary chon-
drites and 2 that are reclassified in this paper
from type 3 to type 4 are listed in Table 6 with
some of their properties. Data for paired speci-
mens are listed under the name of the specimen
with the lowest number (Graham, 1980). Histo-
grams of olivine and low-Ca pyroxene analyses
in 11 of these chondrites are shown in Figures
64 and 65 (less and more metamorphosed chon-
drites, respectively). Table 7 lists the number of
analyses, mean fayalite and ferrosilite concentra-
tions, and coefficient of variation, which is the
standard deviation of the analyses (mole% fayal-
ite or ferrosilite) expressed as a percentage of the
mean. Also listed for the olivine analyses is the
percent mean deviation (PMD) of the FeO
weight concentrations in olivine. This parameter,
which was first used by Dodd et al. (1967), is not
as convenient as the standard deviation, but it is
listed because Van Schmus and Wood (1967)
used it to define the boundary between type 3
and 4 chondrites; type 3 chondrites have a PMD
that exceeds 5.
For a normal distribution, the mean deviation
is (TT/2)~1/2 or 0.80 times the standard deviation.
Since mole% Fa and wt.% FeO are not linearly
related, this relationship will not hold exactly for
PMD (calculated from wt.% FeO) and CV (from
mole% Fa or Fs), even neglecting deviations from
normal distributions. For eight of the chondrites
in Figures 64 and 65, the PMD/CV ratios for
low-Ca pyroxene analyses are close to 0.80 (0.76
to 0.82), but for olivine analyses, which are gen-
erally far from normally distributed, the PMD/
CV ratios average 0.63 ? 0.14.
Of the eight other ordinary chondrites that
are listed in Table 6 but not in Table 7, three
have already been described in some detail:
ALHA77O11 (McKinley et al., 1981), ALHA
77278 (McSween and Wilkening, 1980) and
ALHA79003 (Scott, Taylor, and Maggiore,
1982). Another three are described for the first
time by McKinley and Keil (herein, p. 59). The
other two type 3 ordinary chondrites are regolith
breccias: ALHA77215 and Yamato 75028; they
are the only ones for which thin sections were
TABLE 7.?Electron microprobe analyses of olivines and low-Ca pyroxenes in 11 Antarctic
type 3 and 4 ordinary chondrites (br = breccia; PMD = percent mean deviation calculated
from FeO wt.% (see Dodd et al., 1967)).
Specimen
number,
Section
ALHA76004, 8
ALHA77299, 40
ALHA77304, 35,36
ALHA78084, 135
ALHA79022, 14
OTTA80301, 13
RKPA79008, 7
RKPA80205, 12
RKPA80207, 11
RKPA80256, 17
Yamato 74191, 92
Class
LL3
H3-br
L4
H4
L3-br
H3
L3
H3
H3
L3
L3
Anal.
No.
53
38
29
64
49
28
35
36
36
35
74
Olivine
Mean
% Fa
17.3
17.1
25.5
18.7
23.6
18.2
22.6
16.0
18.7
23.8
21.4
o-/mean
%
56
33
3.6
1.7
4.3
6.1
18.1
19.6
22.1
4.7
23
PMD
40
24
2.1
1.6
2.5
2.5
9.0
10.5
12.8
2.8
17.3
Low-Ca pyroxene
Anal.
No.
39
38
22
71
40
35
35
36
37
35
76
Mean
% Fs
12.1
13.7
16.7
16.7
17.7
11.0
15.5
13.0
15.3
15.6
11.8
<r/mean
%
66
49
38
11.7
29
45
39
32
43
30
59
NUMBER 26
CD
Z5
Q-
CD
u_
30
20
10
40
30
20
10
40
30
20
10
40
30
20
10
80
70
20
10
60
20
10
-
JJ m
-
-
-
i ?
-
-
-
?m--
-
-
?^^?'
_
-
-
OLIVINE LOW-CA PYROXENE
10 20 30 10 20 30
' Allan'HillsA76004 ' (LL3)
JbL J^ Lk H L LL
? Yamato 74191 (L3)
1 i1
? Reckling Peak A80207 (H3)
1 jJ
MM
?
? ^
?^
m Allan Hills A77299 (H3-br)1
1
m Reckling Peak
I
J
A80205 (H3)
' _ Reckling Peak A79008 (L3)
h ] j
10 15 20 25 30 35 0 5 10 15 20 25 30
Fayalite (mole %) Ferrosilite (mole %)
a
-
-
-
-
-
?r
c
-
-
-
?r
d-
-
-
-
?r
e
-
-
f
-
-
30
20
10
40
30
20
10
40
30
20
10
40
30
20
10
20
10
20
10
35
77
FIGURE 64.?Histograms of electron-probe analyses of randomly chosen olivine and low-Ca
pyroxenes in six mildly or moderately metamorphosed type 3 ordinary chondrites from
Antarctica (Table 7). Chondrites are arranged in approximately increasing order of their
proportion of equilibrated olivines. Compositional ranges for equilibrated H, L, and LL groups
are from Gomes and Keil (1980).
78 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
OLIVINE LOW-CA PYROXENE
i i
H LAllan Hills A77304 (L4) H L a
Allan Hills A79022 (L3-br)
I Outpost Nunatak A8030I (H3)
Allan Hills A78084 (H4)
10 15 20 25 30 0
Fayalite(mole%)
d
10 15 20 25
Ferrosilite (mole%)
60
40
20
0
60
40
20
0
60
40
20
0
80
40
20
0
60
40
20
0
FIGURE 65.?Histograms of olivine and low-Ca pyroxenes in three well metamorphosed type
3 chondrites and two type 4 chondrites, which were previously classified as type 3 (Table 7).
In all five chondrites, over 90% of the olivines have compositions in the equilibrated H or L
range. However, the proportion of equilibrated low-Ca pyroxenes in each chondrite varies
from 5-70%, and, as in Figure 64, these values are not well correlated with the proportion of
equilibrated olivines. Metamorphism of chondritic components in diverse locations prior to
final lithification accounts for the poor correlations.
NUMBER 26 79
not available during the course of the study. Also
included in Table 6 are ALHA78084 and 77304,
which are here reclassified as type 4 chondrites.
Two ordinary chondrites that have been clas-
sified as type 3 chondrites have been omitted
from Table 6. Yamato 74065 and the paired
specimen 74066 were listed as an L3 chondrite
by Yanai (1979) and by Takeda et al. (1979).
The section loaned to us (Yamato 74066,73),
however, is an L5 chondrite, with olivine Fa23.5
to Fa25.5 and low-Ca pyroxene Fsi95 to Fa22.o-
Yanai et al. (1978) found very heterogeneous
olivines and pyroxenes in Yamato 74492, and
Yanai (1979) listed it as an H3 chondrite. How-
ever, section 74492,81 is an H6 chondrite with
homogeneous olivine, Fai8.5, and low-Ca pyrox-
ene, Fsie.o-
In the brief review below of petrologic and
chemical studies that are relevant to the classifi-
cation of these chondrites, the original descrip-
tions and analyses by King et al. (1980), Score,
Schwarz, et al. (1982) and Score, King, et al.
(1982) are not referred to unless there are con-
flicting data. However, these papers are the pri-
mary source of petrologic information for many
of the type 3 ordinary chondrites. Possible spec-
imen pairings are discussed below; except where
noted in Tables 6 and 8, it appears that these
samples are not paired, but a few cases deserve
further study.
ALHA76004.?The first type 3 chondrite to
be recovered from Antarctica is one of the least
TABLE 8.?List of specimens paired with ALHA77011, L3
chondrite (* = small samples; see Table 3 herein).
77015
77031*
77033
77034*
77036*
77043*
77047*
77049*
77050*
77052*
77115*
77140
77160
77163*
77164
77165
77166*
77167
77170*
77175*
77178*
77185*
77211*
77214
77241*
77244*
77249
77260
77303*
78038
78188
79001
79045
80133
equilibrated. Figure 64a shows that its olivines
are more heterogeneous than any of the other
10 chondrites analyzed. Like ALHA77176, the
other very primitive ordinary chondrite, it con-
tains abundant opaque matrix (Huss et al., 1981),
which was analyzed by Ikeda et al. (1981). De-
tailed petrologic descriptions of ALHA76004
are provided by Olsen et al. (1978), who classified
it as an LL3, and Ikeda (1980). Although the
oxygen isotopic composition of clasts in
ALHA76004 are more extreme than those re-
ported for components in other ordinary chon-
drites (Mayeda et al., 1980), this chondrite may
not be more unusual than other primitive chon-
drites, such as Bishunpur and Semarkona.
ALHA77011.?This meteorite and the paired
specimens (Table 8) all contain a few volume
percent of graphite-magnetite aggregates (Mc-
Kinley et al., 1981). These samples are paired
with some confidence because other type 3 chon-
drites contain much less graphite-magnetite, ex-
cept for Sharps, which has 11 vol.%. However,
Sears et al. (1982) believe that the samples may
represent two falls, as their thermoluminescence
sensitivity values vary by a factor of 3. Extensive
sampling of a large type 3 chondrite would be
useful to help establish what variation in chemical
and physical properties can be expected in a
single meteorite.
Chondrules in ALHA77011 (Nagahara,
1981a, 1981b; Fujimaki et al., 1981; data on
specimen ALHA77015) do not seem to be dif-
ferent from those in other ordinary chondrites.
Ikeda et al. (1981) argue that the opaque matrix
in three ALHA77O11 specimens is different in
composition from matrices in three other ordi-
nary type 3 chondrites. Chiefly on the basis of
the Na/Al ratio, they find that the matrix of
77011 resembles matrices in C2 and C3 chon-
drites. However, Na/Al matrix ratios in Sharps
and Krymka (Huss et al., 1981) are nearly as low
as that of 77011. The bulk composition of this
meteorite (Jarosewich, 1980; Rhodes and Fulton,
1981) appears to be typical for L chondrites
(McKinley et al., 1981).
ALHA77215.?This is only the sixth L chon-
80 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
drite known to contain solar-wind gases (Gos-
wami, 1981). It and the three paired specimens
(Table 6) contain 47 vol.% of mineral, lithic, and
chondrule fragments (Score, 1980), and solar-
flare tracks (Nautiyal et al., 1982). Like many
other chondrite regolith breccias, this meteorite
also contains graphite-magnetite aggregates
(Scott, Rubin, et al., 1981).
ALHA77278.?Although 77278 is very rich
in In and Tl (Biswas et al., 1980), McSween and
Wilkening (1980) found that its olivine is not as
unequilibrated as might be expected. ALHA
76004, for example, has olivines that are more
heterogeneous (Figure 64?) although its In and
Tl concentrations (Biswas et al., 1981) are lower.
McSween and Wilkening (1980) and King et al.
(1980) classify ALHA77278 as an LL chondrite
on the basis of Co concentrations in kamacite
and a bulk chemical analysis by Jarosewich
(1980). Jarosewich and Dodd (1981) concur with
this classification.
This meteorite is only one of four ordinary
chondrites (all LL) known to contain carbides
and magnetite (Taylor et al., 1981; Scott, Taylor,
and Maggiore, 1982). Equilibrated chondrules,
but not clasts, were identified by Scott, Taylor,
Keil, (1982), and a carbonaceous clast was ten-
tatively identified by King et al. (1980). Weber
et al. (1983) found significant excess 4He in
ALHA77278, indicative of solar-wind gases.
However, its Ne isotopic ratios marginally fail
the suggested requirements of Wasson (1974) for
a solar-gas-rich meteorite.
ALHA77299.?The mean composition of ol-
ivine (Figure 64d) and the abundance of metallic
Fe,Ni enabled King et al. (1980) to classify 77299
as an H3 chondrite. Analyses by Jarosewich
(1980), Rhodes and Fulton (1981), and Biswas et
al. (1980) confirm this classification. Additional
petrologic descriptions are provided by Haggerty
et al. (1979) and Ikeda etal. (1981). An H4 clast
is described in the section on breccia properties.
ALHA77304.?This meteorite was classified
by King et al. (1980) as an LL3 chondrite, but
the data in Table 7 and Figure 65? indicate that
it should be classified as L4 because of its ho-
mogeneous olivine; PMD is 2.1, mostly Fa25 to
Fa26. Although King et al. (1980) found more
heterogeneous olivine (Fai8 to Fa27), B. Mason
and H. Nagahara (private communications) con-
firm the L4 classification of ALHA77304. King
et al. (1980) note that clasts up to 1 cm in
diameter are visible on the surface of this chon-
drite.
ALHA78084.?This 14 kg meteorite was ini-
tially classified as an H3 chondrite (Score, King,
et al., 1982), but the homogeneity of its olivine
in Figure 65e (PMD of olivine is 1.6) is more
appropriate to type 4 (Van Schmus and Wood,
1967). Extensive weathering probably made the
interchondrule material more opaque, and the
chondrules more prominent than normal for a
type 4 chondrite. The opaque matrix typical of
type 3.0-3.6 ordinary chondrites (Huss et al.,
1981) is absent.
ALHA79003.?This tiny meteorite was
paired with ALHA79001 by Score, King, et al.
(1982) but unpaired by Scott, Taylor, and Magg-
iore (1982). The latter authors identified 79001
as a specimen of ALHA77011, and reclassified
79003 as the third Antarctic LL3 chondrite. As
with non-Antarctic type 3 ordinary chondrites,
these three LL3 chondrites are less equilibrated
than most Antarctic H3 and L3 chondrites.
ALHA79022.?Score et al. (1981) found het-
erogeneous olivines with Faj to Fa28 and classi-
fied this meteorite as an H3, but Figure 656
shows that some areas have very homogeneous
olivine typical of L4 chondrites (very largely Fa23
to Fa25). On the assumption that the more het-
erogeneous areas represent matrix and that the
meteorite does not contain a mixture of H and
L material, 79022 is classed as an L3 breccia in
Table 6. Limited published data on ALHA77215
are similar to those of this meteorite, suggesting
that the possibility of pairing needs more study.
ALHA77304, which is another L3-4 breccia,
has olivines with significantly higher FeO concen-
trations (Figure 65a) than 79022. However, com-
paring heterogeneous breccias is clearly a diffi-
cult task.
OTTA80301.?Score, Schwarz, et al. (1982)
NUMBER 26 81
tentatively classified this meteorite from Outpost
Nunatak as an H3 chondrite, and this classifica-
tion is retained here, even though its olivine
composition in Table 7 (PMD of olivine equals
2.5) is too uniform for a type 3. All but two of
28 olivine analyses in Figure 65d lie in the range
Fai8.2 to Fai8.9, entirely appropriate for H4 chon-
drites. However, if one more olivine grain had
been encountered that was a little richer in for-
sterite than the most Mg-rich olivine actually
analyzed (Fai3), then the PMD of olivine could
have exceeded 5, the upper limit for type 4
chondrites. Thus it may be very difficult to apply
this criterion with confidence to distinguish type
3 and 4 chondrites without many hundreds of
analyses over a large surface area.
RKPA79008.?Silicate analyses in Figure
64/ are entirely consistent with those of Score,
King, et al. (1982) and their classification of RKPA
79008 as an L3. Olivine compositions in
RKPA80256, which is also a moderately equili-
brated L3, are slightly more fayalitic (mostly Fa22
to Fa24). Although the variation to be expected
in a single meteorite is not well known, it seems
best to assume that these specimens are not
paired.
RKPA80205.?Olivine analyses in Figure 64^
are consistent with the tentative classification of
80205 as an H3 (Score, Schwarz, et al., 1982).
RKPA80207 is an H3 chondrite with similar
silicate heterogeneity, which was presumably
found in the vicinity of 80205. However, it can
be distinguished from 80205 as its olivine is
richer in fayalite (Figure 64c, e), assuming that
the sections analyzed are representative of the
whole specimens. Thermoluminescence sensitiv-
ity results of Sears and Weeks (1983) on the two
specimens are also significantly different, al-
though their result for 80207 is not consistent
with the silicate analyses in Table 7.
RKPA80207.?The low concentration of me-
tallic Fe,Ni in this chondrite indicated to Score,
Schwarz, et al. (1982) that it is an L chondrite.
However, the position of the prominent peak in
the histogram of olivine analyses (Fai6 to Fa2o,
Figure 64c) strongly suggests that it is an H
chondrite, especially as severe weathering of this
specimen hinders accurate estimates of its metal
abundance.
RKPA80256.?Silicate analyses in Figure 65c
confirm the tentative classification of this mete-
orite as an L chondrite (Score, Scharz, et al.,
1982). However, the olivine PMD of 2.8 (Table
7) is too low for a type 3. Because of the difficulty
of measuring PMD accurately (p. 76), the type 3
classification of Score, Schwarz, et al., is retained.
Yamato 74191.?This chondrite is one of the
least equilibrated type 3 chondrites from Antarc-
tica (Figure 64b). Detailed studies of its chon-
drules and abundant translucent matrix are pro-
vided by Kimura et al. (1979), Ikeda and Takeda
(1979), and Ikeda et al. (1981).
Yamato 75028.?This H3 chondrite contains
solar-wind gases (Takaoka et al., 1981) and is
only the second chondrite regolith breccia found
in Antarctica. Petrologic descriptions of the H3
matrix and more equilibrated clasts are given by
Takeda et al. (1979), Ohta and Takeda (1982),
and Miyamoto et al. (1982).
Petrologic Subtypes
Type 3 ordinary chondrites have recently been
subdivided according to the degree of meta-
morphism that they have experienced (Sears et
al., 1980; Huss et al., 1981). The decimal subdi-
vision into types 3.0 to 3.9, which was proposed
by Sears and coworkers, has been adopted by
most people and is based on measurements of
thermoluminescence sensitivity. This parameter
appears to be the most useful for classifying type
3 ordinary chondrites. Sears et al. (1980, 1982)
have shown that many properties of these chon-
drites are so well correlated that chondrites can
be classified into subtypes by other parameters if
thermoluminescence data are not available. The
subtypes, listed in Table 6 for 18 chondrites are
from Sears et al. (1982) and Sears and Weeks
(1983), except for ALHA79003, for which ther-
moluminescence data are not available. Sears and
coworkers claim that thermoluminescence data
permit subtype classification to a 1 a uncertainty
82 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
s
*=60
50
O40
8
*=30
O 20-
10-
o
A77I76
A76004
t 1 i t i
A79003
X H
oL
? LL
A77278
A77299
3207 ? !
O Y74I9I "i
A77013 R790O8O
O iA77I97
R80205
R80256 x08030| |
? OA79022 A78O84T
QA773O4 E
3.0 3.2 3.4 3.6
Petroloqic type
3.8
FIGURE 66.?Plot of coefficient of variation of olivine com-
positions (aFa/mean Fa) from Table 6 against petrologic
subtype from Sears et al. (1982) and Sears and Weeks (1983)
for 17 Antarctic type 3 and 4 ordinary chondrites. With
the exception of RKPA80207 and RKPA80256, and
ALHA79022 and ALHA77304, olivine coefficients are
close to the ranges shown for the subtypes (Sears, et al.,
1982). These four chondrites have much more homogene-
ous olivine than would be predicted from the thermolumi-
nescence sensitivity data of Sears and coworkers. The dashed
line for RKPA79008 is an estimate of the ?2<r error in its
coefficient of variation.
1.0-
0.61-
O
8 0.4
%
O 0.2-
1?
-
. 1
-
-
-
I
,
?1?
I
?1 1 1
OA770II
I _I
 :
A77278
? ? ?
-i 1 1
X
o
?
TA77299
?
H
L
LL
I
A772I5 A78084
A77304 o0 ; A
3.0 3.2 34 3.6
Petrologic type
3.8
FIGURE 67.?Plot of bulk carbon concentration against sub-
type for six type 3 ordinary chondrites. The limited C data
from Jarosewich (1980), Gibson and Andrawes (1980), and
Grady et al. (1982) scatter widely from the ranges predicted
by Sears et al. (1980). The dashed line shows the range of C
concentrations in ALHA77299 obtained by these authors.
f
(J00
100
1?
o
oo
o
A770II
A76004"
H
L
LL
TA77278 X
A77304
? ^A772I5
1
3.0 3.2 3.4 3.6
Petrologic type
3.8
FIGURE 68.?Primordial 36Ar concentrations in Antarctic
type 3 ordinary chondrites decrease with increasing subtype
and are close to the subtype ranges in Sears et al. (1980).
Noble gas analyses are by Weber and Schultz (1980), Tak-
aoka et al. (1981), Nautiyal et al. (1982), Kaneoka (1980),
Moniot et al. (1981), and Weber et al. (1983).
0.2
0.15
? 0.
|
O0.05o
O
^77176
Sem
R80207:;
R80256
A79O22J
3.0 3.2 3.4 3.6
Petrologic type
3.8 4-6
FIGURE 69.?Mean CaO concentrations of randomly chosen
olivine grains are inversely correlated with subtype in type
3 ordinary chondrites. Data from Noonan et al. (1977) for
St. Mary's Co. (StM); S.G. McKinley (private communica-
tion) for ALHA77011, ALHA77013, ALHA77176, and
ALHA77197; remainder including Semarkona (Sem), this
work. Vertical bars for individual meteorites are ?2a of
mean values; ranges of types 4-6 from Busche (1975).
NUMBER 26 83
of ?0.1, except in cases of extensive weathering,
which may lower the thermoluminescence sensi-
tivity and the subtype. Shock may also affect the
thermoluminescence sensitivity (Sears, 1980).
Figures 66-68 show data for Antarctic type 3
ordinary chondrites, illustrating the inverse cor-
relations of petrologic subtype with coefficient
of variation of olivine (<rFa/mean Fa) and the
concentration of C and primordial 36Ar. Also
marked are the ranges expected within subtypes
from Sears et al. (1980, 1982). Unfortunately,
bulk C and Ar concentrations have only been
measured in about one-third of the Antarctic
type 3 ordinary chondrites. However, in general,
assignments based on olivine heterogeneity and
C and 36Arp concentrations are within 0.2 of the
subtype derived from thermoluminescence sen-
sitivity data.
Dbdd (1969, 1981) finds that CaO concentra-
tions in olivine vary according to petrologic type
in ordinary chondrites: type 3 olivines have ^0.1
wt.% CaO, type 4 have 0.06 wt.%, and type 5-6
0.02-0.05 wt.% CaO. Figure 69 shows that even
though CaO concentrations in olivine may vary
widely within a single type 3 chondrite, the mean
value can also be used to classify type 3 chon-
drites according to subtype with an accuracy
better than ?0.2. Chondrites that do not lie on
the trends in Figures 66-69 are discussed below.
RKPA80207.?The subtype of 3.2 assigned
by Sears and Weeks (1983) is not consistent with
the degree of homogeneity of its olivine (Figure
66) and low-Ca pyroxene, which both have peaks
in the H range (Figure 64c), and its low CaO
concentration in olivine (Figure 69). These pa-
rameters and the absence of fine-grained, FeO-
rich, opaque silicate matrix, or "Huss matrix"
(Huss et al., 1981) indicate that type ~3.6 might
be a better classification.
ALHA77O11.?This L3 chondrite has higher
concentrations of C and 36Arp than expected for
its subtype of 3.4-3.5 (McKinley et al., 1981;
Sears et al., 1982). Excess C can be attributed to
abundant graphite-magnetite.
ALHA79022, ALHA77304 and RKPA
80256.?These three L chondrites have olivines
that are too homogeneous and low in CaO to be
consistent with their thermoluminescence data.
The latter suggest type 3.6 to 3.7 (Sears and
Weeks, 1983), whereas olivine compositions sug-
gest type 3.9 or 4.
Although the boundary between types 3 and
4 chondrites is quantitatively defined by Van
Schmus and Wood (1967) in terms of olivine
heterogeneity (PMD of wt.% Fe is 5), in practice,
the distinction is difficult to make. As discussed
in the description of OTTA80301, the presence
of a few percent of very heterogeneous olivines
in a chondrite that contains largely homogeneous
olivine can drastically affect the PMD. Thus
hundreds of analyses on several sections would
be needed to establish the PMD with any confi-
dence. Unfortunately, the thermoluminescence
senstivities of type 4 chondrites are largely indis-
tinguishable from type 3.8-3.9 chondrites (Sears
et al., 1980). It appears that the boundary be-
tween type 3 and 4 chondrites must remain in-
distinct, like the boundary between type 4 and 5
chondrites.
Another difficulty with the classification
scheme of Van Schmus and Wood (1967) con-
cerns the classification of breccias. Regolith brec-
cias, such as Dimmitt (Rubin et al., 1983) and
ALHA77215, are defined as type 3 chondrites
because their matrices have small amounts of
heterogeneous silicates. It seems worthwhile to
distinguish breccias, regolith and otherwise, in
classification schemes by adding suffixes like
those in Table 6.
Some of the above problems in classifying type
3 chondrites according to their subtype may be
due to heterogeneities and the presence of equil-
ibrated clasts. Such clasts have been identified in
the regolith breccias, ALHA77215 (Score, 1980)
and Yamato 75028 (Ohta and Takeda, 1982).
During the course of this study of type 3 chon-
drite thin sections, only one equilibrated clast
was identified, an H4 clast in ALHA77299 (Fig-
ure 70). However, this clast was found acciden-
tally as a result of random probe analyses of its
silicates, and was not prominent in the thin sec-
tion. King et al. (1980), Score, Schwarz, et al.
(1982), and Score, King, et al. (1982) mention
clasts in their descriptions of many of the type 3
84 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
I mm
FIGURE 70.?Thin section of ALHA77299 (H3). Line marks approximate boundary between
H4 clast on left and H3.7 matrix on right. Clast contains olivine with Fais.4?o.2 (l<r of analyses)
and 0.03 wt.% CaO, and low-Ca pyroxene with Fs16.i?o.4. The matrix contains some chondrules
like those in the clast, some with equilibrated olivine and unequilibrated low-Ca pyroxene, and
others with unequilibrated olivines and pyroxenes (see Figure 7l?).
chondrites, e.g., inclusions of various colors up
to 7 mm in size are present on the surface of
ALHA79022. Unfortunately, it is not known
whether these are chondritic clasts; some might
be large irregular chondrules.
Brecciation and Metamorphism
Dodd et al. (1967) and Dodd (1969) argue
convincingly that mineralogic differences among
type 3 chondrites are the result of metamorph-
ism. Olivine homogeneity is correlated with the
degree of integration of chondrules and matrix,
and the glass abundance in chondrules. Similarly,
Huss et al. (1981) find that olivine homogeneity
is also correlated with the proportion of opaque
matrix and its Fe/(Fe+Mg) ratio. They also at-
tribute most of these mineralogic variations in
type 3 chondrites to mild metamorphism of the
whole rocks.
By contrast, Dodd (1971, 1974) found in
Sharps (H3.4) and Hallingeberg (L-3.3) a sig-
nificant proportion of chondrules with mineral-
ogic features that he attributes to metamorphism
before the rocks were lithified. These chondrules
NUMBER 26 85
are relatively homogeneous in composition, have
lower CaO concentrations in olivines, and are
commonly zoned with rimward increases in FeO
concentration in olivine, with or without concur-
rent decreases in CaO.
Scott, Taylor, and Keil (1982) studied three
moderately metamorphosed type 3 ordinary
chondrites, Ngawi (LL3.6), ALHA77278
(LL3.6), and Bremervorde (H3.7), and found in
each a significant proportion of chondrules with
olivine homogeneity and CaO concentrations ap-
propriate to type 4 chondrites. Because metallic
Fe,Ni grains in these three chondrites had cooled
at very diverse rates, they argue that chondrules
and metal grains were metamorphosed at various
depths inside the parent bodies before the three
chondrites were lithified.
To check whether any other Antarctic type 3
chondrites are breccias of unequilibrated and
equilibrated material, olivine and low-Ca pyrox-
ene grains were analyzed in over 100 chondrules
in six chondrites. Figures 71 and 72 show the
mean and la ranges of analyses for CaO and
fayalite concentrations in 4-10 olivine grains in
each chondrule. Yamato 74191 (L3.6), ALHA
77299 (H3.7), RKPA80205 (H3.7) and RKPA
79008 (L3.7) all contain a significant proportion
of chondrules that have olivine and low-Ca py-
roxene compositions like those in type 4 chon-
drites (Figure 71). Unequilibrated chondrules
have olivines with fayalite ranges and mean CaO
concentrations that are generally 5-20 and 2-6
times larger, respectively, than olivines in equil-
ibrated chondrules.
In two of these chondrites, ALHA77299 and
RKPA79008, the presence or absence of chon-
drule rims composed of opaque Huss matrix
(Huss et al., 1981) is related to olivine heteroge-
neity in the chondrules. Most of the unequili-
brated chondrules and none of the equilibrated
chondrules in these two chondrites have partial
rims of opaque Huss matrix (Figure 7la, b). In
Yamato 74191 and RKPA80205, none of the
analyzed chondrules have rims of opaque matrix.
Yamato 74191 has abundant matrix, but it is all
translucent and in parts recrystallized, and it is
often difficult to decide which chondrule, if any,
is rimmed where matrix material separates adja-
cent chondrules.
Figure 72? shows analyses of olivine in 15
chondrules from ALHA76004 (LL3.3). None of
the chondrules have mean olivine compositions
appropriate to equilibrated LL chondrites (Fa27.5
to Fa30.5)- All are heterogeneous and have mean
CaO concentrations of 0.05-0.3 wt.%, like the
unequilibrated chondrules in Figure 71. By con-
trast, Figure 12b shows analyses for 16 chon-
drules in RKPA80256, which has more equili-
brated olivines (Figure 65c) than the chondrites
described above. Only two chondrules have
mean olivine compositions outside the L4-6
range. For comparison, analyses of chondrules
in Richardton (H5) and Bjurbole (L4) are shown
in Figure 72c. Richardton chondrules contain
olivine that is more homogeneous and has lower
CaO concentrations than Bjurbole chondrules.
Both sets of chondrules are more equilibrated
than those in RKPA80256.
It might be argued that olivine in some of the
chondrules plotted in Figure 71 preserved its
heterogeneity and high CaO concentrations
from in situ equilibration with the matrix or other
chondrules because of large crystal or chondrule
sizes. However, the unequilibrated chondrules
are not on average larger or coarser grained than
the equilibrated chondrules. Figure 73 shows
photomicrographs of unequilibrated and equili-
brated porphyritic-olivine chondrules in each of
the three chondrites shown in Figure 71. In two
cases the equilibrated chondrule is larger and has
larger olivine phenocrysts than the unequili-
brated chondrule. In the other case (Figure 73a,
b), chondrule and phenocryst sizes are very sim-
ilar.
Another possible barrier to equilibration be-
tween olivines is the presence of silicates or other
phases that have low diffusion rates for Fe and
Mg. For example, olivines poikilitically enclosed
by low-Ca pyroxene might be expected to lag
behind other olivines during metamorphic equil-
ibration. However, none of the analyzed olivines
in the unequilibrated chondrules plotted in Fig-
ures 71 and 72 are poikilitically enclosed by
pyroxene or any other mineral. There do not
86 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
0.29
0.05
Allan Hills A77299
chondrules
o rimmed by opaque matrix
x opaque matrix rim absent
? equilibrated clast
EQUILIBRATED
-CHONDRULES
K) 20
Fayalite (mole%)
0.3
0.2
0.15
0.05
Yamato 74191
chondrules
15 20
Fayalite {mole %)
0.3
0.25
P 0.2
Oo 0.15
0.1
0.05
n
Reckling Peak A79008 b
, chondrules
o rimmed by opaque matrix
x no opaque matrix rim
?
1 <
?
?
?
?
Tu 1J1 ? i ,
1
-
p* I EQUILIBRATEDJ?.^CHONDRULES ?
I
0.3
0.25
0.2
O 0.15
O.I
0.05
15 20
Fayalite (mole%)
25
Reckling Peak A80205
chondrules
EQUILIBRATED
-CHONDRULES
10 15 20
Fayalite (mole%)
25 30
FIGURE 71.?Plots of mean CaO concentration in olivine against mean fayalite concentration
for 75 porphyritic-olivine and porphyritic-olivine-pyroxene chondrules in four Antarctic type
3 ordinary chondrites. Bars show ?la values for 4-10 analyses in each chondrule; \a values
that are not plotted are comparable to the smallest shown. In all four chondrites there are
unequilibrated chondrules containing olivine with variable Fa and CaO concentrations and
>0.05% CaO, and chondrules with uniform Fa and CaO concentrations and <0.05% CaO in
olivine. Chondrules were metamorphosed to different extents before final lithification into
chondrites. The boxes showing the compositions of equilibrated chondrules are defined by
ranges in type 4-6 H and L chondrites (Gomes and Keil, 1980; Busche, 1975).
appear to be any systematic differences in the
mineral textures of unequilibrated and equili-
brated chondrules except perhaps in their me-
sostases, which are generally, but not always,
more crystalline in the latter.
The most plausible explanation for the juxta-
position of equilibrated and unequilibrated chon-
drules in many of the Antarctic type 3.6 to 4
chondrites is that equilibrated chondrules were
metamorphosed prior to lithification of the chon-
NUMBER 26 87
0.3
0.25
0.2
0.15
0.1
0.05
Allan Hills A76004
chondrules
10 15 20
Fayalite (mole %)
30
0.08
0.07
0.06
? 0.04
D
? 0.03
0.02-
0.01
Richardton (H5)
chondrules
Bjurbdle(L4)
chondrules
C"
EQUILIBRATED
CHONDRULES
L_s
16 20 22 24
Fayalite (mole %)
0.08
^ 0.06p
O 0.04o
o
0.02
Reckling Peak A80256
chondrules
b.
?1
t_ ' H
T T
1T
1 X
x x
> EQUILIBRATEDCHONDRULES
20 22 24 26 28 30
Fayalite (mole%)
FIGURE 72.?Plots of mean CaO concentration in olivine
against mean fayalite concentration: a, 15 chondrules in
ALHA76004 (LL3.3); b, 16 chondrules in RKPA80256
(L3.6); r, 9 chondrules in Richardton (H5) and 10 in Bjur-
bole (L4). Unlike the chondrites in Figure 71, ALHA76004
contains no equilibrated chondrules, whereas in
RKPA80256 chondrules are nearly all equilibrated with
mean analyses plotting within the box defined by mean
olivine compositions in L4-6 chondrites. The ranges of CaO
and Fa concentrations in olivine and the CaO concentration
itself within and among chondrules decrease from type 3 to
type 5 chondrites. Most type 3 chondrites, including
RKPA80256, appear to be mixtures of type 3 and 4 chon-
drites. (The upper limit of Fa concentrations in L4-6 chon-
drites from Gomes and Keil (1980) should be extended
slightly to include the Bjurbole data).
drites. These chondrites are, therefore, breccias
composed of materials metamorphosed in di-
verse locations. The argument is strongest for
the chondrites shown in Figure 71. But even for
RKPA80256 (Figure 12b), it seems probable that
some or all of the equilibration between chon-
drules and matrix occurred before compaction
of the chondrite. The two chondrules plotting
outside the equilibrated chondrule box in Figure
12b are smaller and have smaller grain sizes than
many of the equilibrated chondrules. Thus,
much of the material in this chondrite may have
been metamorphosed to type 4 levels prior to
final lithification. However, metamorphism to
type 3.6-3.8 levels after compaction cannot be
excluded.
Chondrules in RKPA80207 and OTTA
80301, in which olivines are largely equilibrated
(Figures 64c, 65d), were not analyzed in such
detail. However, in each chondrite a porphyritic-
olivine chondrule with heterogeneous olivine
(Fa 13 to Fa 19 and Fa 12 to Fa 15, respectively) with
appreciable CaO concentrations (0.03-0.21
wt.%) was discovered. Since these chondrules are
not especially large or coarse-grained, it is con-
cluded that these two chondrites are also breccias
of previously metamorphosed materials.
Figure 64 shows that the proportion of equil-
ibrated chondrules in each of the four chondrites
shown in Figure 71 varies considerably. Further-
more, the nature of the equilibrated chon-
drules in these four chondrites also varies. In
88 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
FIGURE 73.?Photomicrographs of six porphyritic-olivine chondrules in type 3.7 ordinary
chondrites in transmitted light: a and b, ALHA77299; c and d, RKPA79008; e and /,
RKPA80205. Olivine in the three chondrules on the left is heterogeneous (a, Faio to Fa2o; c,
Fa4 to Fai.5; e, Faio to Fai4) and contains high CaO concentrations (0.03-0.31 wt.% CaO),
whereas olivine in the three chondrules on the right is more homogeneous (Fa]8 to Fa2o in b
and/, Fa23 in d) with low CaO concentrations (0.01-0.06 wt.%). Data for these and other
chondrules are plotted in Figure 71. Some of the unequilibrated chondrules like c have rims of
fine-grained, FeO-rich, silicate material ("Huss matrix"), but none of the equilibrated chon-
drules have such rims. These chondrites and many other type 3 ordinary chondrites are breccias
of materials with diverse metamorphic histories.
NUMBER 26 89
ALHA77299, many of the equilibrated chon-
drules have low-Ca pyroxene with compositions
appropriate to H4-6 chondrites (Fsi6 to Fai8).
Their presence accounts for the peak at Fsi6 to
Fsi8 in the histogram of randomly chosen pyrox-
ene grains (Figure 64d). For Yamato 74191,
however, the low-Ca pyroxene histogram shows
no such peak in the equilibrated L range (Fsi9 to
Fs23), and the equilibrated chondrules lack py-
roxenes with this composition. In fact, equili-
brated chondrules in ALHA77299 seem to be
more equilibrated than those in some types 3 and
4 chondrites shown in Figure 65, which overall
have much more homogeneous olivines.
ALHA77304 and RKPA80256, for example,
lack equilibrated low-Ca pyroxenes even though
their olivines, in general, appear to be more
equilibrated than those of ALHA77299. Thus,
various degrees of mixing between materials that
have been metamorphosed to various extents can
account for the strange lack of coherence be-
tween the compositions of olivine and low-Ca
pyroxene in the histograms shown in Figures 64
and 65.
Virtually all of the type 3 ordinary chondrites
in which mineral compositions have been studied
in individual chondrules appear to contain chon-
drules with diverse metamorphic histories. These
include Sharps and Hallingeberg (Dodd, 1971,
1974), Mezo-Madaras (Van Schmus, 1967),
Ngawi, ALHA77278, and Bremervorde studied
by Scott, Taylor, and Keil (1982) and the seven
Allan Hills chondrites discussed above. Van
Schmus (1969) argues that components in C3O
chondrites also experienced metamorphism
prior to compaction of the meteorites. If all type
3 chondrites are mixtures of material with dif-
ferent metamorphic histories, why can they be
considered to a good approximation as a se-
quence of rocks that were metamorphosed to
various degrees after lithification? Why are their
chemical and textural properties that are con-
trolled by metamorphism so well correlated?
Presumably, the answer to these questions is
that, in general, the materials mixed do not have
very diverse metamorphic histories. Ngawi seems
to have the most extreme components; un-
equilibrated chondrules rimmed with abundant
opaque matrix and equilibrated chondrules with
homogenous olivine and low-Ca pyroxene (Scott,
Taylor, and Keil, 1982). However, in other type
3 chondrites, the range of metamorphic histories
represented is much smaller, or else the propor-
tion of material with an unusual thermal history
is very small. Brecciation does explain why the
properties of type 3 ordinary and carbonaceous
chondrites are not better correlated. Ngawi, for
example, would be classified as a type 3.3 from
the composition of its opaque matrix, but type
3.7 from its bulk C concentration (Sears et al.,
1982). Some "measures of metamorphism" are
controlled solely by the properties of the least
unequilibrated chondrules, whereas others are
controlled more by the proportion or nature of
the most equilibrated chondrules. Bulk thermo-
luminescence sensitivity, which varies by a factor
of 104 in type 3 chondrites, is very sensitive to
the amount of equilibrated (type 4) material.
Variable degrees of metamorphism may be re-
sponsible for some of the spread in the TL sen-
sitivities of individual chondrules in Dhajala
found by Sparks et al. (1983).
Some of the results in this paper might be used
to argue against the thesis that metamorphism
caused equilibration and recrystallization. Kurat
(1969) and Fredriksson et al. (1975) suggest that
uniform olivine and pyroxene compositions are
a result of crystallization, and not metamorph-
ism. However, like Dodd et al. (1967), Huss et
al. (1981), and most other workers, I believe that
all ordinary chondrites were formed by meta-
morphism (and brecciation) of materials very
similar to the most primitive type 3 ordinary
chondrites. Although Fredriksson, Kurat, and
coworkers are correct in arguing that constant
olivine compositions were not established in situ
in these breccias, there is very strong evidence
that metamorphism in precursor rocks was re-
sponsible (Dodd, 1969). Type 3 chondrites con-
tain suites of chondrules that have virtually iden-
tical textures (except in their mesostases and
rims) but vary widely in silicate heterogeneity.
Chondrules may contain heterogeneous olivine
and low-Ca pyroxene, homogeneous olivine and
90 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
heterogeneous pyroxene or olivine and low-Ca
pyroxene that are entirely homogenous. This is
consistent with the much higher cation diffusion
rates in olivine compared to those in pyroxene;
Jones (1983) estimates that olivine diffusion rates
are 103 times higher.
The presence of some proportion of equili-
brated chondrules in many type 3.5-4 chondrites
means that it is possible to classify chondrites on
the basis of the olivine composition in these chon-
drules, even when much of the olivine is hetero-
geneous. Although Dodd (1968) believed he had
identified three equilibrated LL chondrules in
the H chondrite, Sharps, no such aberrant chon-
drules were encountered in this study. Mixing of
material from different ordinary chondrite
groups seems to be very limited, even on parent-
body surfaces (Keil, 1982; Rubin et al., 1983).
Of the seven Antarctic type 3 chondrites that
have been identified above as breccias, only one,
ALHA77299, is known to contain chondritic
clasts. Brecciation in type 4-6 chondrites is easier
to identify than in type 3 chondrites as more
metamorphosed materials are generally better
lithified and thus form clasts rather than chon-
drules when broken. 'Metamorphosed' chon-
drites that contain a small fraction of minerals
with aberrant compositions or textures, e.g.,
Bhola (Noonan et al., 1978) and Pulsora (Fred-
eriksson et al., 1975), are generally recognizable
as breccias of previously metamorphosed mate-
rial. However, all others, e.g., Morro do Rocio
(Wlotzka and Fredriksson, 1980), must be brec-
cias also, unless the aberrant minerals have been
isolated from diffusive equilibration by barriers
such as large grain size.
Summary
Four carbonaceous type 3 chondrites from
Antarctica are known: one C3V, RKPA80241;
two C3O, ALHA77003 and 77029, and a unique
C3, ALHA77307. Yamato 6903 may be a C4V.
ALHA80133 is an L3 chondrite paired with
ALHA77011,notaC3V.
Seventeen different ordinary type 3 chondrites
from Antarctica are recognized. ALHA77304 is
reclassified from LL3 to L4, ALHA78084 from
H3 to H4, and RPKA80207 from L3 to H3.
Analyses of sections of ALHA79022, OTTA
80301, and RPKA80256 suggest that they are
type 4 meteorites, but because of the difficulty
of determining PMD olivine when a small per-
centage of chondrules are heterogeneous, they
have not been reclassified from type 3 to
type 4. ALHA77299 (H3) contains an H4
clast but is not rich in solar-wind noble gases
(Weber et al., 1983). Two type 3 chondrites are
regolith breccias, ALHA77215 and Yamato
75028.
In general, silicate analyses are consistent with
the subtype classification from thermolumines-
cence sensitivity data by Sears and coworkers.
However, RKPA80207 appears to be a type
-3.6 not a 3.2. ALHA79022, ALHA77304 and
RKPA80256 have olivine compositions indica-
tive of type 3.9 or 4, rather than 3.6 to 3.7, as
Sears and Weeks (1983) suggest.
The mean concentration of CaO in olivine is
another parameter like olivine heterogeneity
that is inversely correlated with subtype, decreas-
ing from 0.15 to 0.2 wt.% for type 3.0-3.3 to
=?0.05 wt.% for type 3.7-4.
Seven type 3.5-4 ordinary chondrites contain
equilibrated chondrules with CaO and FeO con-
centrations in their olivines like those of type 4
chondrites, even though some of their chon-
drules have heterogeneous olivines like those in
type 3.0-3.5 chondrites. Metamorphic equilibra-
tion must have occurred before lithification of
the chondrites. Probably all type 3 chondrites
are breccias composed of chondrules with diverse
metamorphic histories.
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Sparks, M.H., P.M. McKimmey, and D.W.G. Sears
1983. The Thermoluminescence Carrier in the Dhajala
Chondrite. Journal of Geophysical Research,
88(supplement):A773-A778.
Takahashi, H., M-J. Janssens, J.W. Morgan, and E. Anders
1978. Further Studies of Trace Elements in C3 Chon-
drites. Geochimica et Cosmochimica Acta, 42:97-106.
Takaoka, N., K. Saito, Y. Ohba, and K. Nagao
1981. Rare Gas Studies of Twenty-Four Antarctic Chon-
drites. Memoirs of the National Institute of Polar
Reseach (Japan), special issue, 20:264-275.
Takeda, H., M.B. Drake, T. Ishii, H. Hamamura, and K.
Yanai
1979. Some Unique Meteorites Found in Antarctica and
Their Relation to Asteroids. Memoirs of the National
Institute of Polar Research (Japan), special issue,
15:54-76.
94 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
Taylor, G.J., A. Okada, E.R.D. Scott, A.E. Rubin, G.R.
Huss, and K. Keil
1981. The Occurrence and Implications of Carbide-
Magnetite Assemblages in Unequilibrated Ordi-
nary Chondrites. In Lunar and Planetary Science
XII, pages 1076-1078. Houston: Lunar and Plan-
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Van Schmus, W.R.
1967. Polymict Structure of the Mezo-Madaras Chon-
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2042.
1969. Mineralogy, Petrology and Classification of Types
3 and 4 Carbonaceous Chondrites. In P.M. Mill-
man, Meteorite Research, pages 480-491. Dor-
drecht, Holland: D. Reidel Publishing Company.
Van Schmus, W.R., and J.A. Wood
1967. A Chemical-Petrologic Classification for the
Chondritic Meteorites. Geochimica et Cosmochimica
Ada, 31:747-765.
Wasson, J.T.
1974. Meteorites?Classification and Properties. 316 pages.
Heidelberg: Springer-Verlag.
Weber, H.W., O. Braun, L. Schultz, and F. Begemann
1983. The Noble Gas Record in Antarctic and Other
Meteorites. Zeitschriftfur Naturforschung, 38a:267-
272.
Weber, H.W., and L. Schultz
1980. Noble Gases in Ten Stone Meteorites from Ant-
arctica. Zeitschrift fur Naturforschung, 35a:44-49.
Wlotzka, F., and K. Fredriksson
1980. Morro do Rocio, an Unequilibrated H5 Chon-
drite. Meteoritics, 15:387-388.
Yanai, K.
1979. Catalog ofYamato Meteorites in the Collection of Na-
tional Institute of Polar Research, 188 pages. Tokyo:
National Institute of Polar Research.
Yanai, K., M. Miyamoto, and H. Takeda
1978. A Classification for the Yamato-74 Chondrites
Based on the Chemical Compositions of Their
Olivines and Pyroxenes. Memoirs of the National
Institute of Polar Research (Japan), special issue,
8:110-120.
A Meteorite from the Moon
Ursula B. Marvin
On 18 January 1982, John Schutt spotted a
small meteorite with a frothy greenish tan fusion
crust lying near the edge of the Middle Western
Icefield of the Allan Hills region (Figure 74).
Large white clasts lying in a dark matrix were
clearly visible beneath patches of crust and on a
broken surface. After two seasons of collecting
Antarctic meteorites, Schutt, who had led the
United States search party for the first half of
that season, immediately recognized the speci-
men as unique. Laboratory studies have since
shown that the specimen is a meteorite from the
Moon; the first one ever found on Earth.
Schutt was not out that day primarily to search
for meteorites. He was guiding a visitor, Ian
Whillans of Ohio State University, on a recon-
naissance trip to examine the regional configu-
ration of the ice sheet. After a 31 km snowmobile
ride over long stretches of rough snowdrifts they
decided to turn back. A steady wind and blowing
snow made visibility poor, so it was by sheerest
chance that Schutt saw the plum-sized specimen
as they cruised near the edge of the icefield.
Schutt photographed the meteorite in situ
(Figure 75) and collected it by the customary
sterile procedures. That evening the weather
deteriorated so rapidly that further field work
became impossible. The lunar rock was the final
addition to that season's trove of 373 specimens.
Months later, at the NASA Johnson Space
Center in Houston, Roberta Score unpackaged
Ursula B. Marvin, Smithsonian Astrophysical Observatory, 60
Garden Street, Cambridge, Massachusetts 02138.
the meteorite in a nitrogen-filled processing cab-
inet (Frontispiece). She described it as an unusual
looking sample with an abundance of angular
gray to white clasts, from about 1 to 8 mm in
size, set in a black matrix (Score, 1982). It
weighed 31.4 grams and measured 3 X 2.5 X 3
centimeters. It was assigned the name Allan Hills
81005 (ALHA81005).
From a thin section, made at the Smithsonian
Institution in Washington, Brian Mason classified
the rock as an anorthositic breccia. He found the
white clasts to consist mainly of Ca-rich plagio-
clase, making the meteorite much more feld-
spathic than the eucrites. Mason wrote in the
Antarctic Meteorite Newsletter that "some of the
clasts resemble the anorthositic clasts described
from lunar rocks" (Mason, 1982).
News spread quickly of the Antarctic meteor-
ite that looked like a lunar rock, but the story
broke too late for sample requests to be submit-
ted in time for the September 1982 meeting of
the Meteorite Working Group. Unwilling to wait
until the following April, the MWG issued a
special Newsletter in November announcing the
availability of samples for initial characterization.
The intent was to obtain sufficient general infor-
mation from thin sections and matrix chips to
guide the formation of a multidisciplinary con-
sortium to study individual clasts. The deadline
for submitting sample requests was 1 December
1982. In order to give investigators an equal
chance to report their findings, all were asked to
delay public announcement of their results until
the 14th annual meeting of the Lunar and Plan-
95
96 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
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- 2
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NUMBER 26 97
FIGURE 75?An in situ photograph of the meteorite
ALHA81005 as it lay on the ice. It is a rounded individual
with an angular notch where a piece was broken off. White
clasts are visible beneath a thin, frothy fusion crust.
etary Science Conference to be held in Houston
in March 1983.
On 4 December, the Meteorite Working
Group held a special session at which three-
fourths of the participants were conscripts sub-
stituting for regular members who had submitted
proposals. Twenty-five requests were received
and twenty-two were approved. The remaining
three were postponed for integration into the
consortium. The types of studies authorized for
the initial round were electron microprobe anal-
yses of thin sections (with five sections being
shared by eight investigators), instrumental and
radiochemical neutron activation analyses of
bulk and matrix samples, measurements of re-
flectance spectra, ferromagnetic resonance, no-
ble gas abundances, nuclear particle tracks, oxy-
gen isotopes, and cosmogenic isotopes.
At the special session on Allan Hills 81005,
held at the Houston Conference on St. Patrick's
Day, a wholly unprecedented degree of unan-
imity prevailed. All participants agreed that the
specimen probably came from the Moon; most
said it positively came from the Moon; none said
it did not come from the Moon.
The fragmental fabric of the breccia is illus-
trated in Figure 76, a photomosaic of thin section
ALHA81005,22. A heterogeneous array of min-
eral and rock clasts and masses of devitrified glass
are embedded in a dark brown, glassy matrix.
The matrix, defined as material with a grain size
less than 25 /xm, occupies about 60%, and the
clasts about 40% of the area. Some clasts show
shock effects, such as crushing and partial optical
randomization of crystals, but others, including
several delicately twinned feldspars, are un-
shocked.
As first suggested by Mason, the white clasts
do indeed resemble those of lunar highlands
anorthositic rocks. Plagioclase (An94 to An98) is
the most abundant component in the clasts and
glasses, including the dark brown matrix glass.
Colorless, pale yellow, and light orange glass
spherules are scattered throughout the breccia,
and patches of highly vesicular, swirly glass,
formed by the remelting of glass-bonded agglu-
tinates, occur in the matrix (Figure 77). The
spherules and reworked agglutinates identify the
rock as a soil breccia.
The most common clasts are recrystallized
breccias, melt rocks, and devitrified glasses, but
the breccia also contains a few clasts of cataclastic
ferroan anorthosites, anorthositic gabbros, and
troctolites, some of which are probably pristine.
The largest clast in thin section ALHA81005,22
is a cataclastic ferroan anorthositic gabbro (Fig-
ure 78A) consisting of 87% plagioclase (An96-
An98) and 13% pigeonite (En64Fs34Wo2) and fer-
roaugite (En25Fs32Wo42). This rock clearly be-
longs to the well-established pristine ferroan an-
orthosites, but it is more Fe-rich than previously
analyzed samples.
A different type of anorthositic gabbro consists
of chains of pyroxenes and olivines lying in a
matrix of granulitic plagioclase (Figure 78B). The
plagioclase is An97; the finely exsolved pyroxenes
98 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
5 mm
FIGURE 76.?A photomosaic of thin section
ALHA81005,22 showing the heterogeneous array of clasts
and glasses in the dark glassy matrix. Clasts 1-4 are shown
at higher magnifications in Figures 77 and 78.
FIGURE 78.?Three types of lithic clasts in section
ALHA81005,22. A, Cataclastic anorthositic gabbro in which
the plagioclase is partially optically randomized by shock
pressure (clast 2 in Figure 76). B, Anorthositic gabbro with
a quasi-cumulate texture. Chains of olivines and pyroxenes
lie amid granulitic plagioclase, but large clasts of twinned
plagioclase are also present indicating that the rock is a
recrystallized breccia (clast 3 in Figure 76). c, Clast consisting
of a 430-jum plagioclase lath attached to a mass of black
glass. The gray-patterned areas in the lath are patches of
glass of the same composition as the plagioclase (clast 4 in
Figure 76). (All three clasts photographed in transmitted
light). D, Photomicrograph in reflected light of the black
glass, showing five phases: rows of opaque crystallites of
armalcolite and one larger crystallite of ulvospinel on edge
of glass (lower left), brighter and duller bands of glass, and
two minute spherules of metallic Fe (bright dots amid crys-
tallites in lower half of picture). This coarse clast may be a
fragment of mare basalt.
FIGURE 77.?Clasts and matrix textures in thin section
ALHA81005,22. A, Lopsided spherule of colorless glass lies
adjacent to a swirly mass of tawny-brown glass full of minute
vesicles, which appear as black dots. The vesicular glass is a
remelted glass-bonded agglutinate, a type of particle that is
abundant in lunar soils. B, Small clast (a) of possible low-K
mare basalt (Clast 1 in Figure 76) lies between a light-colored
granulite (b) formed by the recrystallization of an impact
breccia, and a rounded mass of light brown, devitrified glass
(c). (Both photomicrographs taken in transmitted light).
NUMBER 26 99
100 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
are En38_45Fs3o-44Woi1_32; the olivine is Fo40, by
far the most iron-rich mafic mineral reported to
date in ALHA81005. Three large crystals of
twinned plagioclase (An97) are also present, in-
dicating that the clast is a recrystallized breccia
despite the appearance of a cumulate texture.
Several clasts of mare basalts have been found
mixed with the predominantly highlands ma-
terials in the breccia. Fragments of Very Low
Titanium (VLT) mare basalt were discovered
in thin sections by Tremaine and Drake (1983)
and Ryder and Ostertag (1983). In section
ALHA81005,22 a clast consisting of a single 430
lim lath of plagioclase (An97) attached to a mass
of black Ti-rich glass may be a fragment of high-
titanium mare basalt (Figure 78C,D). The glass is
studded with rows of opaque crystallites, chiefly
armalcolite, (Fe,Mg)Ti2O5, and one larger crys-
tallite of ulvospinel (FeTi2O4). The black glass
contains about 0.22 wt.% K2O, more than twice
the amount measured in the plagioclases of the
breccia. The glass appears to be a sample of
mesostasis from a medium-grained basalt (Mar-
vin, 1983).
A small diabasic clast (Figure 77B) consisting
of 86% bytownite (An85_89Abio-i40r0.8-i.i), au-
gite, and glassy mesostases containing silica glass,
K-feldspar, apatite, and ilmenite may represent
a low-potassium mare basalt (Marvin, 1983).
A strong indication of lunar origin is provided
by the ratios of manganese to iron oxides in the
pyroxene minerals of the clasts. Systematic dif-
ferences in FeO/MnO partitioning in rocks from
different sources were first demonstrated by
Laul and Schmitt (1973), and subsequent studies
have established separate fields for lunar rocks
and the various classes of achondritic meteorites.
Values for the pyroxenes in ALHA81005 plot in
the lunar field as shown in Figure 79.
The major-element composition of the bulk
sample closely resembles highland materials from
the Apollo 16 and Luna 20 missions. However,
the contents of minor and trace elements, partic-
ularly potassium, rare earth elements, and phos-
phorus (KREEP) are markedly lower than those
found in the highlands samples previously ana-
lyzed. Remote sensing analyses of the lunar sur-
face, by orbiting spacecraft and ground-based
telescopes, indicate that areas of KREEP-poor
anorthositic crust occur along the far eastern
limb of the Earth-facing side, and on the farside
of the Moon. Some investigators (e.g., Pieters,
1983) are searching these regions for a youthful
impact crater large enough to have been the
source of ALHA81005. The site should lie
within 100 km or so of mare surfaces of appro-
priate compositions to account for the basalt
clasts that were present in the regolith.
Other lines of evidence for a lunar origin
include the oxygen isotopic ratios that bear a
distinctly lunar signature (Mayeda et al., 1983),
the presence in the matrix of solar wind-im-
planted noble gases (He, Ne, Ar, Kr, and Xe) in
concentrations and relative abundances similar
to those in gas-rich lunar soils and breccias (Bo-
gard and Johnson, 1983b), and the absence of
galactic particle tracks in the mineral grains,
consistent with a short flight time in space (Sutton
and Crozaz, 1983). These and additional inves-
tigations are reported in a special issue of Geo-
physical Research Letters (1983) devoted to
ALHA81005.
This sample was clearly spalled off the Moon
into an Earth-crossing orbit from a site not visited
by either the United States Apollo missions or
the Soviet Union's Luna missions. Thus, that
end-of-season snowmobile trip to the Middle
Western Icefield of the Allan Hills region has
been nicknamed "the Apollo 18 mission" (Koro-
tev, Haskin, and Lindstrom, 1983).
Our examination of ALHA81005 has taught
us, once again, that natural events frequently
confound the results of all our calculations. Pre-
dictions from experimental impacts and com-
puter modeling told us that the only material
that could escape the Moon would come from
deep below the target area of an impacting pro-
jectile and be shock-melted to glass or crushed
and dispersed as glassy droplets. But, contrary to
these predictions, ALHA81005 is not a rock
derived from deep in the lunar crust; it is a
welded surface soil, no more highly shocked and
glassy than many a sample that the astronauts
lifted off the lunar surface with tongs. A new
NUMBER 26 101
model is now being constructed (Melosh, 1983),
which involves the spalling off of blocks of sur-
face materials at low pressures in front of oblique
impacts.
Most of the meteorites collected in the past are
believed to have come from asteroids, with a few
possibly derived from comets. During the past
two centuries nearly 700 meteorite falls have
been witnessed and some of the fireballs have
been photographed. All of the well-documented
trajectories show that the meteorites were follow-
ing elliptical orbits that originated in the asteroid
belt between Mars and Jupiter. Lunar ejecta
must also fall on Earth whenever huge meteorites
impact the Moon with sufficient energy to accel-
erate target materials above the lunar escape
velocity of 2.4 km per second. Statistical studies
have suggested that such impacts happen very
infrequently, and it is likely that none has oc-
curred in historic time. We now know, however,
that such an event did occur sometime within the
past few million years while the great ice sheet
has covered Antarctica. Perhaps the fall occurred
less than a million years ago. The first attempt
to measure the terrestrial age (time since the fall
to Earth) of ALHA81005 gave ambiguous results
(Evans and Reeves, 1983). However, as shown
by Nishiizumi (herein, p. 105), the oldest terres-
trial ages yet measured on Antarctic meteorites
are in the order of 700,000 years. If meteorite
concentrations occur on older patches of ice they
have not yet been discovered. We await with
much interest age determinations on the other
meteorites and, if possible, on ice itself at the
Middle Western Icefield.
Systematic searches of the Middle Western
Icefield have not yet been made, but that area
appears promising not only because of the lunar
meteorite but because eight specimens (including
a rare enstatite achondrite) were discovered
there during two brief helicopter visits in the
1978-1979 season. Present plans call for a camp
to be set up nearby and a careful search made in
the 1983-1984 season. Meanwhile, the discovery
of ALHA81005 has raised many questions. Did
this specimen fall on Earth as a single stone, or
did it fall as one piece of a great mass of lunar
wt.% FeO
FIGURE 79.?The partitioning of FeO and MnO in lunar
samples and achondritic meteorites. The black dots, which
represent values measured in pyroxenes of ALHA81005,
plot in the lunar field although some of them extend the
previously determined range toward achondrite values. The
pyroxene ratios plot on and above the lunar whole rock
trendline while the olivine ratios (triangles) plot on and
below it, thus demonstrating a lunar bulk composition. (The
fields for achondrites are taken from Stolper et al., 1979).
debris that was scattered broadcast over our ro-
tating planet? Or did ALHA81005 break off
from a larger incoming mass that exploded in
the atmosphere and showered fragments over
Antarctica? The possibility that this specimen is
a shower fragment will inspire the field party to
search the area with high hopes of discovering
additional pieces of this meteorite from the
Moon.
Would we have recognized this unique mete-
orite as a lunar rock if we had never examined
samples from the Moon? Perhaps not, if we had
found it much more than a decade ago, because
the anorthositic character of the lunar crust came
to us as a complete surprise at the time of the
Apollo 11 mission. Even then, however, one of
the Surveyor modules had sent back analyses
indicating a Ca-Al-rich type of crustal rock, and
orbital missions have since produced compo-
sitional maps of much of the lunar surface. It
seems likely that the anorthositic character of
ALHA81005 and its marked chemical, mineral-
ogical, and isotopic differences from the basaltic
achondrites would have persuaded some scien-
tists to propose a lunar origin for it.
102 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
The discovery of a lunar meteorite has given
new credibility to the hypothesis, first proposed
about five years ago, that the shergottites, a rare
class of achondrites represented by nine speci-
mens (two from Antarctica and seven from other
continents) may have come from Mars. Origi-
nally, this hypothesis was based on isotopic age
determinations, which showed that the shergot-
tites crystallized only about 1.3 X 109 years ago.
Age determinations on other meteorites show us
that the asteroids were already cold and solid
about 4.5 X 109 years ago, soon after the solar
system formed. Even Earth's moon ceased flood-
ing its basins with basaltic lava flows about 3.1 X
109 years ago. Only a larger body, such as Mars,
would be well-insulated enough to retain heat
and remain volcanically active to comparatively
recent times. Mars has huge volcanic cones on its
surface, and crater counts on the surrounding
lava flows show them to be young in comparison
to the ancient, more heavily cratered terranes.
Can the shergottites be samples of these flows?
Recent measurements show that nitrogen, ar-
gon, krypton, and xenon trapped in glassy lenses
in one of the Antarctic shergottites (EETA
79001) are similar in relative abundances and
isotopic ratios to those of the gases in the Martian
atmosphere, measured by the Viking Landers
(Bogard and Johnson, 1983a; Becker and Pepin,
1983).
The case for Martian shergottites is still highly
speculative. The escape velocity from Mars is
about 5 km per second, an acceleration that
seems prohibitive to many investigators. In the
past, many have argued that we could not expect
to find Martian rocks on Earth unless we also
find samples from our closer neighbor, the
Moon. That objection, at least, has now been
removed.
Antarctica has proved to be a rich source of
meteorites, which lie on certain patches of bare
ice awaiting discovery. To journey to Antarctica
is an elegant way to add to our collections of
planetary samples while we await future missions
into space. The discovery of a lunar sample on
that windy January day in the Allan Hills has
opened an awesome new potential and enhanced
immeasurably the excitement of the Antarctic
meteorite program.
This work was supported in part by NASA
grant NAG 9-29.
Additional papers on this meteorite may be
found in a special issue of Geophysical Research
Letters, 10 (September, 1983).
Literature Cited
Becker, R.H., and R.O. Pepin
1983. Heavy Nitrogen in Glass from Antarctica Mete-
orite EETA79001 [Abstract]. EOS, 64:253.
Bogard, D.D., and P.Johnson
1983a. Martian Atmospheric Gases Trapped in the
EETA79001 Shergottite? In Lunar and Planetary
Science XIV: Session on Meteorites from Earth's Moon,
pages 53-54. Houston: Lunar and Planetary In-
stitute.
1983b. Trapped Solar Gases in the ALHA81005 Lunar
(?) Meteorite. In Lunar and Planetary Science XIV:
Session on Meteorites from Earth's Moon, pages 1-2.
Houston: Lunar and Planetary Institute.
Evans, J.C., andJ.H. Reeves
1983. Aluminum-26 Content of ALHA81005. In Lunar
and Planetary Science XIV: Session on Meteorites from
Earth's Moon, pages 6-7. Houston: Lunar and
Planetary Institute.
Korotev, R.L., L.A. Haskin, M.M. Lindstrom
1983. Lunar Highlands Breccia 81005 (ALHA): So
Apollo 18 Flew, but Where Did It Sample? In
Lunar and Planetary Science XIV: Session on Meteorites
front Earth's Moon, pages 12-13. Houston: Lunar
and Planetary Institute.
Laul,J.C., and R. Schmitt
1973. Chemical Composition of Apollo 15, 16, and 17
Samples. In Proceedings of the Fourth Lunar
Science Conference. Geochimica et Cosmochemica
Ada, supplement 4, 2:1349-1367.
Marvin, Ursula B.
1983. The Discovery and Initial Characterization of Al-
lan Hills 81005: The First Lunar Meteorite. Geo-
physical Research Letters, 10:775-778.
Mason, Brian
1982. In Antarctic Meteorite Newsletter, 5 (4).
Mayeda, T.K., R.N. Clayton, and C.A. Molini-Velsko
1983. Oxygen and Silicon Isotopes in ALHA 81005.
Geophysical Research Letters, 10:799-800.
Melosh, H.J.
1983. Impact Ejection, Spallation and the Origin of Cer-
NUMBER 26 103
tain Meteorites. Lunar and Planetary Science XIV:
Session on Meteorites from Earth's Moon, pages 21-
22. Houston: Lunar and Planetary Institute.
Pieters, Carle
1983. If ALHA81005 Came from the Moon, Can We
Tell from Where? In Lunar and Planetary Science
XIV: Session on Meteorites from Earth's Moon, pages
27-28. Houston: Lunar and Planetary Institute.
Ryder, G., and R. Ostertag
1983. ALHA 81005: Petrographic Components of the
Target. In Lunar and Planetary Science XIV: Session
on Meteorites from Earth's Moon, pages 29-30. Hous-
ton: Lunar and Planetary Institute.
Score, Roberta
1982. In Antarctic Meteorite Newsletter 5 (4).
Stolper, E., H.Y. McSween, Jr., andJ.F. Hays
1979. A Petrogenetic Model of the Relationship be-
tween Achondritic Meteorites. Geochimica et Cos-
mochimica Acta, 43:589-592.
Sutton, S.R., and G. Crozaz
1983. Thermoluminescence and Tracks: Constraints on
the History of This Unusual Meteorite. In Lunar
and Planetary Science XIV: Sessions on Meteorites from
Earth's Moon, pages 33-34. Houston: Lunar and
Planetary Institute.
Tremaine, A.H., and M.J. Drake
1983. Meteorite from the Moon: Petrology of Terrae
Clasts and One Mare Clast in ALHA 81005,9. In
Lunar and Planetary Science XIV: Session on Meteorites
from Earth's Moon, pages 35-36. Houston: Lunar
and Planetary Institute.
Cosmic-Ray-Produced Nuclides in
Victoria Land Meteorites
Kunihiko Nishiizumi
In the last few years measurements of cosmic-
ray-produced nuclides in Antarctic meteorites
have been carried out by several groups. At the
present time, we have measured 53Mn (ti/2= 3.7
X 106 y) in 153 meteorites (62 Victoria Land
meteorites and 91 Yamato meteorites) by the
destructive neutron-activation method (Nishi-
izumi, Imamura, et al., 1979; Nishiizumi et al.,
1981; Nishiizumi, Arnold, Imamura, etal., 1982;
Nishiizumi, Arnold, Elmore, et al., 1983; Ima-
mura et al., 1979, Goswami and Nishiizumi,
1983) and 36C1 (t1/2= 3.0 X 105 y) in 62 Antarctic
meteorites by Accelerator Mass Spectroscopy
(Nishiizumi, Arnold, et al., 1979, Nishiizumi et
al., 1981, 1983, and Nishiizumi, unpublished).
26Al (t 1/2 = 7.2 X 10.5 y) has been measured in
129 Victoria Land meteorites by the Battelle
group using nondestructive gamma-ray analysis
(Evans et al., 1979, 1982). In addition to the
above data, nine 10Be (ti/2 = 1.6 X 106 y), and
eighteen 14C (5730 y) measurements, and twenty-
six sets of noble gas data are also available for
our study.
Cosmogenic nuclide concentrations in a me-
teorite give us the cosmic-ray exposure age in
space and terrestrial age on the earth, if we know
the expected equilibrium concentrations and
half-lives. It is important to measure two or more
cosmogenic nuclides in the same meteorite.
Table 9 is a compilation of published and
Kunihiko Nishiizumi, Department of Chemistry, B-017, University
of California, San Diego, La Jolla, California 92093.
unpublished data for Victoria Land meteorites
for which measurements of more than one nu-
clide are available. This table also includes the
exposure age and terrestrial age of these mete-
orites. The exposure age was calculated from the
cosmogenic 21Ne content; the shielding condition
was corrected by the 22Ne/21Ne ratio or from
cosmogenic 40K content. The terrestrial age of
the meteorite was calculated from 36C1 or 14C
content, comparing it with the saturated activity
level that was expected at the time of fall on
Antarctica. The details are discussed in a recent
paper (Reedy et al., 1983).
The measurement of terrestrial age is an im-
portant subject for Antarctic meteorites. The
terrestrial ages of non-Antarctic stone meteorites
are less than 3 X 104 years, usually much less.
However the terrestrial ages of Allan Hills me-
teorites range from 1 X 104 (ALHA77256) to 7
X 105 years (ALHA77002). This age not only
gives us information on the accumulation mech-
anism of meteorites and the history of the Ant-
arctic ice sheet, but also about ancient meteorite
influx rates. Our interest was focused on Allan
Hills meteorites for terrestrial age measure-
ments. So far, several features have appeared.
Meteorites found on the northwest part of the
Allan Hills blue ice region have shorter terres-
trial ages than meteorites found on the southeast
part. Probably this feature gives key information
for the accumulation mechanism of Allan Hills
meteorites and glaciology. On the other hand
there is no clear correlation between the terres-
105
TABLE 9.?Activity (dpm/kg), exposure age, and terrestrial age of meteorites in which
more than one nuclide has been measured (numbers in parentheses indicate half-life of
each nuclide).1
Specimen
number
ALLAN HILLS
ALHA76001
ALHA76002
ALHA76003
ALHA76004
ALHA76005
ALHA76006
ALHA76007
ALHA76008
ALHA76009
ALHA77001
ALHA77OO2
ALHA77003
ALHA77004
ALHA77009
ALHA77015
ALHA77081
ALHA77167
ALHA77214
ALHA77216
ALHA77230
ALHA77249
ALHA77250
ALHA77255
ALHA77256
ALHA77257
ALHA77258
ALHA77260
ALHA77261
ALHA77262
ALHA77270
ALHA77272
ALHA77273
ALHA77278
ALHA77280
ALHA77282
ALHA77283
ALHA77285
ALHA77289
ALHA77290
ALHA77294
ALHA77297
ALHA77299
ALHA77304
ALHA78043
Class
L6
IA
L6
LL3
Eu
H6
L6
H6
L6
L6
L5
C3
H4
H4
L3
H?
L3
L3
L3
L4
L3
IA
Anom
Di
Ur
H6
L3
L6
H4
L6
L6
L6
LL3
L6
L6
IA
H6
IA
IA
H5
L6
H3
L4
L6
53Mn
(3.7xl06y)
443?33
556?21
431?25
390?36
453?33
332?26
22?3
477?34
422?13
255?8
317?13
326?13
162?8
137?7
151?6
348?14
362?15
181?9
565?22
385?15
400?21
181?8
434?18
150?8
302?13
327?13
494?20
213?11
224?11
264?11
325?16
384?17
437?17
394?16
534?21
504?20
433?17
428?17
317?19
211?9
457?22
Activity2
10Be 26A1
(1.6Xl06y) (7.2X105y)
58?2
89?9
51?1
45?4
3.9?0.5 11?1
52?5
30?3
19?2 45?5
52?5
32?2
36?4
42?4
37?2
15?1 56?6
40?3
51?3
37?2
29?2
37?2
36?4
47?5
40?3
18?2 35?4
31?2
28?3
49?3
38?4
67?4
70?7
43?4
50?3
33?3
36C1
(3.0X105y)
14.1?0.5
9.4?1.0
20.1?1.2
4.6?1.1
18.4?1.2
15.2?0.5
10.7?0.2
17.O?O.8
14.9?0.5
15.6?0.2
19.2?0.2
9.8?0.8
12.2?0.4
ll.l?0.6
6.7?0.1
6.6?0.3
6.2?0.3
10.9?0.7
12.2?0.3
12.1?0.4
17.5?O.3
13.6?0.5
15.3?0.3
15.1?0.3
20.8?0.6
19.6?0.2
18.9?0.8
7.3?0.3
14C
(5730y)
<1.0
<1.7
<1.2
<1.7
0.62?0.06
0.65?0.02
0.35?0.03
16.0?1.5
<0.5
1.07?0.24
1.6?0.3
<0.60
Exposure
age
10?y
45
410
53
26
10
28
33
(1.5)
20
20
3.1
5.6
2.4
3.3
30
10
1.8
4.6
21
36
Terrestrial
age
103y
200?80
>34
>32
>34
100?70
<120
700?160
110?70
l70?70
320?70
120?80
180?70
160?70
<130
11?1
360?90
270?70
310?80
530?70
530?80
560?80
320?90
270?70
270?70
110?70
220?70
170?70
17O?7O
30?2
80?40
80?80
490?80
1 Average saturated activity: "Mn: 414?50; 10Be: 20?2; 26A1: 60?7(L), 56?7(H); 36C1: 22.8?3.1;
2 Activity: 5:1Mn: dpm/kg (Fe+'A Ni); 10Be, 26A1, I4C: dpm/kg meteorite; 36C1: dpm/kg metal.
4C: 60.
TABLE 9.?Continued.
Specimen
number
ALHA78076
ALHA78084
ALHA78102
ALHA78105
ALHA78109
ALHA78112
ALHA78114
ALHA78115
ALHA78128
ALHA78130
ALHA78131
ALHA78132
ALHA78232
ALHA81005
BATES NUNATAK
BTNA78002
DERRICK PEAK
DRPA78008
DRPA78009
METEORITE HILLS
META78001
META78002
META78005
META78006
META78010
META78028
MOUNT BALDR
MBRA76001
MBRA76002
PURGATORY PEAK
PGPA77006
RECKLING PEAK
RKPA78003
Class
H6
H4
H5
L6
LL5
L6
L6
H6
H5
L6
L6
Eu
IVA
A
L6
IIB
IIB
H4
L6
L6
H6
H5
L6
H6
H6
IA
L6
53Mn
(3.7xi06y)
427?18
318?13
462?21
444?28
347?16
360?14
334?14
380?15
402?19
376?14
424?18
2.7?0.2
65?3
429?17
394?34
355?26
569?23
363?16
1(>Be
(1.6xl06y)
18?2
21?2
14?2
16?2
18?2
4.1?0.5
Activity2
26 Al
(7.2X105y)
52?4
35?3
61?7
46?3
42?3
38?2
43?3
34?2
51?4
40?3
68?4
46?3
0
53?3
47?3
44?3
60?4
56?3
56?3
50?3
36C1
(3.0X105y)
16.9?0.5
16.4?0.5
14.0?0.6
12.5?0.3
12.4?0.5
13.4?0.5
7.8?0.3
21.6?0.6
15.2?0.4
20.7?0.5
9.3?0.4
9.9?0.2
19.5?0.4
.032?0.004
0.20?0.01
20.5?0.8
21.0?0.5
20.0?0.4
20.9?0.5
21.8?0.5
21.3?0.6
18.4?0.5
19.8?0.4
Exposure
MC age
(5730y) 1Oby
1.41?0.24 37
11
1.01?0.03
1.19?0.30 6
7
Terrestrial
age
lO^y
130?70
140?70
210?80
260?70
260?70
230?70
460?80
<90
17O?7O
<110
380?80
360?70
<130
<120
<100
<120
<100
<90
32?1
31?3
90?70
<130
References:
Column 1: Imamura et al., 1979; Nishiizumi et al., 1979, 1981, 1983; Nishiizumi, Arnold, Imamura, et al., 1982;
Goswami and Nishiizumi, 1983.
Column 2: Moniot et al., 1982; Nishiizumi, Arnold, Imamura, et al., 1982; Nishiizumi, Arnold, Klein, et al., 1982;
Tunizetal., 1983.
Column 3: Evans et al., 1979, 1982; Evans, personal communication; Tuniz et al., 1983.
Column 4: Nishiizumi, Arnold, et al., 1979; Nishiizumi et al., 1981, 1983.
Column 5: Fireman, 1979, 1980, 1983; Fireman and Norris, 1981; Andrews et al., 1982, Nishiizumi, unpublished
data.
Column 6: Nagao and Takaoka, 1979; Nitoh et al., 1980; Schultz et al., 1980; Weber and Schultz, 1980; Takaoka
et al., 1981; Nautiyal et al., 1982; Nagao et al., 1983; Weber et al., 1983.
Column 7: Nishiizumi, herein.
108 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
trial age of a meteorite and its weathering fea-
tures. This indicates that many meteorites stayed
in the ice for a long time and weathering only
began when the specimen was exposed at the ice
surface. Allan Hills meteorites have a wide range
of terrestrial ages and are generally older than
other Victoria Land meteorites and Yamato me-
teorites.
Although the cosmogenic noble-gas data are
important for meteorite bombardment history in
space, relatively small amounts of data are avail-
able for Allan Hills meteorites compared to Ya-
mato meteorites. Based on both cosmogenic sta-
ble (noble gas) and radioactive nuclide data, at
least four Antarctic meteorites showed clearly
multistage irradiation records. They are
ALHA76008, Yamato 7301, 74028, and 74116
(Nishiizumi et al., 1978, 1979, Nishiizumi, Ar-
nold, Imamura, et al., 1982; Imamura et al.,
1979). The multistage irradiation model asserts
that the meteorite was irradiated in a heavily
shielded position in the parent body for a long
time. During this period most of the cosmogenic
stable nuclides (noble gas and 40K) were pro-
duced. The parent body was then fragmented,
initiating the second-stage irradiation by expos-
ing the small preatmospheric bodies to cosmic
rays for a short time so that the long-lived radio-
active nuclides were not saturated. Except for
Antarctic meteorites, Jilin (Kirin) is the only
stony meteorite definitely known to have had a
multistage irradiation record.
An iron meteorite, Derrick Peak A78008, con-
tains the lowest concentration of cosmogenic ra-
dionuclides yet measured among Antarctic me-
teorites. This object is known to be a shower
fragment of DRPA78001-78009 (Clarke, 1982).
Based on a low 53Mn result of (2.7?0.2 dpm/
kg), the preatmospheric size of this group of
Derrick Peak meteorites was more than 3.3 m in
diameter, or more than 150 tons in weight.
Combined analysis of cosmogenic nuclides and
cosmic-ray track data in an aliquot sample pro-
vides information on size and location of a me-
teorite in the preatmospheric body. Such analysis
is extremely useful to check on pairing of Ant-
arctic meteorites. For example, L3 chondrites
ALHA77015, 77167, and 77260 could be frag-
ments from a single meteorite with radius ~25
cm (Goswami and Nishiizumi, 1983). On the
other hand L6 chondrites ALHA77273 and
77280, which were previously suggested to be a
single fall of a meteorite, could not be fragments
from a single meteorite (Goswami and Nishi-
izumi, 1983).
This research was supported in part by NASA
Grant NGL 005-009-148.
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1979. Cosmogenic 53Mn in Antarctic Meteorites and
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G.S. Hall, D. Pal, and G.F. Herzog
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1981. Rare Gas Studies of Twenty-Four Antarctic Chon-
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1983. Recent Cosmic Ray Exposure History of ALHA
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1983. The Noble Gas Record in Antarctic and Other
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Bulk Chemical Analyses
of Antarctic Meteorites,
with Notes on Weathering Effects
on FeO, Fe-metal, FeS, H2O, and C
Eugen e Ja rosewich
In addition to a large number of ordinary
chondrites, the discovery and subsequent collec-
tion of a large number of the Antarctic meteor-
ites has yielded a considerable selection of rare
types. Among these rare types are achondrites,
carbonaceous chondrites, a unique "moon mete-
orite," and several type 3 chondrites, to name a
few. Since these meteorites are rare, they are the
object of extensive studies by researchers from
various disciplines, and their data are compared
with the data from existing specimens in our
collections.
The bulk chemical analysis of some of these
rare meteorites was undertaken as a part of a
broader study of Antarctic meteorites; particu-
larly, the type 3 chondrites, because of the im-
portance of the chemical data in their classifica-
tion.
The bulk chemical analyses of these meteorites
were performed using a modified chemical
method published by Jarosewich (1966). Be-
tween 2 and 20 g of sample were made available
for the analyses of these Antarctic meteorites,
but for actual analysis only between 1.5 and 3.5
g was used. Most of the samples were prepared
in a clean environment with a special automatic
Eugene Jarosewich, Department of Mineral Sciences, National
Museum of Natural History, Smithsonian Institution, Washington,
D.C. 20560.
agate mortar, where the whole sample was
ground, homogenized, and then split for other
studies, including those for trace elements.
As a convenient summary of bulk analyses,
Table 10 gives the data for 17 newly analyzed
chondrites and for 8 meteorites published earlier
by Marvin and Mason (1980). The data in this
table give primarily basic geochemical informa-
tion and indicate the degree of weathering. Six
of the L3 type severely weathered chondrites
(indicated by an asterisk in Table 10) are paired
and their chemical data are given. The chemical
analyses of these L3 types were undertaken be-
fore they were identified as paired. The agree-
ment of the data, considering that they were
obtained on different specimens, is remarkable,
although it is somewhat disappointing that these
rare meteorites are paired rather than separate
specimens. All the data of these meteorites for
FeO, Fe-metal, FeS, H2O and C do not give true
values for these components; nevertheless, with
some corrections, the nature of chemical com-
position of the meteorites can be approximated.
The weathering of the Antarctic meteorites was
described in a general manner by Lipschutz
(1982). Gibson and Andrawes (1980) described
specifics of C and S content and possible condi-
tion of weathering processes, and Marvin and
Motylewski (1980) described the mineralogy of
weathered meteorites.
Ill
112 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE 10.?Chemical composition of Antarctic meteorites (nd = not determined; * =
paired L3 meteorites; H2O = H2O total; Fe,M = Fe-metal; Fe,T = Fe total)
Name and type
ALHA77003
ALHA77005
*ALHA77O11
*ALHA77015
ALHA77155
*ALHA77167
*ALHA77214
ALHA77216
ALHA77219
ALHA77231
*ALHA77249
ALHA77256
ALHA77257
?ALHA77260
ALHA77270
ALHA77271
ALHA77278
ALHA77284
ALHA77294
ALHA77296
ALHA77297
ALHA77299
ALHA77304
ALHA77078
ALHA78106
C3
Sh
L3
L3
L6
L3
L3
L3
M
L6
L3
Di
Ur
L3
L6
H6
LL3
L6
H5
L6
L6
H3
L4
L6
L6
SiO2
34.19
42.40
38.21
38.23
39.99
37.94
37.73
39.43
32.27
39.43
36.96
52.15
41.12
37.53
40.15
36.88
41.03
40.43
37.75
40.21
40.13
35.94
40.49
38.64
39.70
TiO2
0.14
0.46
0.14
0.14
0.13
0.13
0.11
0.10
0.16
0.11
0.12
0.16
0.04
0.13
0.12
0.11
0.12
0.12
0.14
0.14
0.14
0.11
0.14
0.13
0.13
A12O3
2.89
3.14
2.29
2.29
2.21
2.18
2.30
2.25
3.93
2.18
2.21
1.56
<0.1
2.15
2.49
1.97
2.26
2.30
2.31
2.36
2.41
2.27
2.35
2.34
2.36
Cr2O3
0.49
1.05
0.57
0.57
0.54
0.58
0.49
0.49
0.63
0.49
0.53
1.06
0.70
0.56
0.53
0.50
0.50
0.48
0.57
0.57
0.52
0.41
0.57
0.58
0.51
FeO
21.78
19.85
20.07
19.63
16.33
19.64
19.63
15.85
15.84
16.07
21.28
16.07
13.57
21.45
15.46
13.43
16.79
14.50
8.76
15.53
15.43
13.15
16.36
15.57
14.31
MnO
0.31
0.46
0.27
0.26
0.32
0.26
0.33
0.32
0.41
0.31
0.26
0.47
0.38
0.24
0.32
0.28
0.34
0.32
0.33
0.35
0.36
0.30
0.28
0.35
0.36
MgO
23.53
28.16
23.89
23.97
24.70
23.85
22.69
24.57
12.56
24.47
22.91
26.48
39.66
23.82
24.92
23.36
24.08
25.17
23.66
25.00
25.02
22.50
25.10
24.49
25.13
CaO
2.22
3.39
1.78
1.71
1.79
1.64
1.70
1.67
3.14
1.75
1.60
1.50
1.07
1.75
1.79
1.60
1.90
1.78
1.83
1.96
1.93
1.81
1.81
1.86
1.96
Na2O
0.56
0.48
0.92
0.74
0.95
0.91
0.82
0.90
0.15
0.91
0.86
0.04
0.03
0.83
0.96
0.83
0.82
0.91
0.72
0.80
0.80
1.08
1.01
0.74
0.75
K2O
0.06
0.04
0.12
0.10
0.11
0.11
0.07
0.12
0.03
0.12
0.11
0.01
0.01
0.11
0.11
0.10
0.10
0.10
0.07
0.09
0.08
0.12
0.13
0.07
0.07
The degree of weathering in the Antarctic
meteorites is accurately reflected in the prelimi-
nary petrographic description of the meteorites
in the NASA Newsletters. Severely weathered me-
teorites denoted as "C" condition and two "A"
(minor weathering) were selected from Table 10
and are listed in Table 11; in this table the degree
of weathering is quantitatively expressed for
FeO, H2O, FeS, Fe-metal, and C. It can be seen
that the values for H2O, C, and FeO (which
includes weathered metal) are higher and Fe-
metal and FeS are lower than the averages for
their class of meteorites. There are some excep-
tions to this general trend; FeS in ALHA77214
and C in ALHA77271 are very close to the
average amounts of these two components for
their type, and two meteorites in Table 10,
ALHA77278 and ALHA77299, classified as "A"
(minor weathering) show considerable amounts
of H2O and a slight increase in C, and
ALHA77299 shows high FeO and low Fe-metal.
These few variations in an otherwise definite
trend in weathering of different constituents in
meteorites, high FeO, H2O, C, and low Fe-metal
and FeS, would indicate that the weathering is a
very selective process, one dependent on variety
of conditions, the processes of which are little
understood.
The contamination of the Antarctic meteor-
ites, especially those of "A" condition, at this
point, is not a serious problem for most elements
that have been studied (Lipschutz, 1982). How-
ever, it is evident that the carbon contamination
in "C" condition meteorites is significant and its
source is of importance. The suggestion of the
presence of CO2 in secondary minerals was veri-
fied, using classical CO2 determination in "C
condition meteorite, ALHA77214 (for which
NUMBER 26 113
TABLE 10.?Continued.
P2O5
0.23
0.41
0.25
0.25
0.20
0.24
0.21
0.20
0.30
0.23
0.24
0.01
0.06
0.27
0.26
0.22
0.20
0.18
0.25
0.22
0.24
0.22
0.22
0.25
0.22
H2O
1.89
0.02
2.74
2.55
0.49
2.74
3.29
0.75
1.63
0.75
3.34
0.02
0.18
2.99
0.31
1.25
1.58
0.79
0.23
0.20
0.14
1.71
0.99
0.71
0.11
Fe,M
4.50
ND
1.94
2.30
6.09
2.44
2.02
6.40
23.63
6.37
2.25
nd
nd
1.53
5.99
12.90
2.23
5.90
16.00
6.00
6.39
12.26
4.36
6.48
6.78
Ni
1.37
0.01
1.02
1.12
1.34
1.13
1.18
1.13
2.86
1.20
1.17
0.01
0.08
1.11
1.12
1.69
1.03
1.20
1.84
1.26
1.11
1.67
1.16
1.32
1.29
Co
0.07
<0.01
0.06
0.06
0.06
0.06
0.06
0.06
0.10
0.06
0.07
<0.01
<0.01
0.06
0.07
0.09
0.05
0.06
0.06
0.06
0.07
0.08
0.07
0.07
0.07
FeS
4.85
<0.1
4.47
4.69
4.32
4.55
5.73
5.75
1.10
4.88
4.41
0.15
<0.01
3.43
5.34
4.42
6.17
5.16
5.62
4.80
5.24
5.23
4.80
6.03
5.87
C
0.28
0.02
0.97
0.98
0.04
0.99
1.08
0.04
0.15
0.03
1.08
0.03
3.34
1.07
0.01
0.04
0.16
0.01
0.02
0.01
0.01
0.38
0.01
0.02
0.01
Total
99.36
99.89
99.71
99.59
99.61
99.36
99.44
100.03
98.89
99.36
99.40
99.72
100.24
99.03
99.95
99.67
99.36
99.41
100.16
99.56
100.02
99.24
99.85
99.65
99.63
Fe,T
24.51
15.43
20.38
20.54
21.53
20.60
20.77
22.37
36.64
21.96
21.59
12.49
10.55
20.39
21.40
26.15
19.20
20.45
26.38
21.12
21.72
25.80
20.13
22.41
21.64
Ref
2
2
1
1
1
1
2
1
2
1
1
2
2
1
1
1
2
1
1
1
1
2
1
1
1
Degree
ofweathering
2
A
A
C
C
A/B
C
cA/B
B
A/B
C
A/B
A
C
A/B
C
A
A/B
A
A/B
A
A
B
A/B
A/B
1 References: 1 = herein; 2 = Marvin and Mason, 1980, appendix 2.
2 Degree of weathering: A = minor; B = moderate; C = severe.
TABLE 11.?Amounts of most weathered components of weathered meteorites
(A = minor, C = severe).
Name and type
ALHA77011 L3
ALHA77015 L3
ALHA77167 L3
ALHA77214 L3
ALHA77249 L3
ALHA77260 L3
ALHA77271 H6
ALHA77278 LL3
ALHA77299 H3
FeO
20.07
19.63
19.64
19.63
21.28
21.45
13.43
16.79
13.15
H2O
2.74
2.55
2.74
3.29
3.34
2.99
1.25
1.58
1.71
Fe,M
1.94
2.30
2.44
2.02
2.25
1.53
12.9
2.23
12.26
FeS
4.47
4.69
4.55
5.73
4.41
3.43
4.42
6.17
5.23
C
0.97
0.98
0.99
1.08
1.08
1.07
0.04
0.16
0.39
Degreeof
weathering
C
C
cc
cc
c
A
A
114 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
sufficient sample was available), giving 0.19%
CO2, clearly within the range estimated by Gib-
son and Andrawes (1980) from 5% to 10% of
total carbon but still not accounting for the re-
mainder of carbon.
Weathering is not a major concern in the study
of these meteorites; however, the contamination
or depletion of elements is. The relationship
between weathering, which can be readily ob-
served, and contamination is an area to be ex-
plored. This work establishes for a group of
Antarctic meteorites that the presence of H2O
and low Fe-metal with resulting high FeO and
depletion of FeS is accompanied by an increase
of C, which is clearly a contaminant.
The analyses of weathered Antarctic meteor-
ites, especially those of rare types, will be the
source of important additional data, provided
the necessary precautions are exercized in the
acquisitions of these data.
The analyses of carbon in the Antarctic Me-
teorite samples was done by J. Nelen.
Literature Cited
Gibson, E.K., Jr., and F.F. Andrawes
1980. The Antarctic Environment and Its Effect upon
the Total Carbon and Sulfur Abundances in Re-
covered Meteorites. In Proceedings of the Eleventh
Lunar and Planetary Science Conference, pages
1223-1234. New York: Pergamon Press.
Jarosewich, E.
1966. Chemical Analyses of Ten Stony Meteorites. Geo-
chimica et Cosmochimica Acta, 30:1261-1265.
Lipschutz, M.E.
1982. Weathering Effects in Antarctic Meteorites. In
U.B. Marvin and B. Mason, editors, Catalog of
Meteorites from Victoria Land, 1978-1980.
Smithsonian Contributions to the Mineral Sciences,
24:67-69.
Marvin, U.B., and B. Mason, editors
1980. Catalog of Antarctic Meteorites, 1977-1978.
Smithsonian Contributions to the Earth Sciences, 23:
50 pages.
Marvin, U.B., and K. Motylewski
1980. Mg-Carbonates and Sulfates on Antarctic Mete-
orites. Lunar and Planetary Science XI, pages 669-
670. Houston: Lunar and Planetary Institute.
Appendix
Tables of Victoria Land Meteorites
Terminology
Class and type: A = achondrite, unique; Au = aubrite; C = carbonaceous chondrite; Di =
diogenite; E = enstatite chondrite; Eu = eucrite; H = high-iron chondrite; Ho = howardite; I
= iron (IA, IIA, IIB, IVA = iron groups); L = low-iron chondrite; LL = low-iron low-metal
chondrite; M = mesosiderite; Sh = shergottite; Ur = ureilite. Chondrite type is indicated by
the digit following the letter.
Olivine composition in mole percent Fe2SiO4(Fa).
Pyroxene (orthopyroxene or low-Ca clinopyroxene) composition in mole percent FeSiO3(Fs).
Degree of weathering: A = minor; metal flecks have inconspicuous rust halos, oxide stain
along cracks is minor. B = moderate; metal flecks show large rust halos, internal cracks show
extensive oxide stain. C = severe; specimen is uniformly stained brown, no metal survives.
Degree of fracturing: A = slight; specimen has few or no cracks and none penetrate the
entire specimen. B = moderate; several cracks extend across the specimen, which can be readily
broken along the fractures. C = severe; specimen has many extensive cracks and readily
crumbles.
Locations: ALH = Allan Hills; BTN = Bates Nunatak; DRP = Derrick Peak; EET =
Elephant Moraine; MBR = Mount Baldr; MET = Meteorite Hills; OTT = Outpost Nunatak;
PCA = Pecora Escarpment; PGP = Purgatory Peak; RKP = Reckling Peak; TIL = Thiel
Mountains.
Classification: by SJ.B. Reed and S.O. Agrell (*); by S.G. McKinley and K. Keil (**).
Abbreviations: n.d. = no data.
NOTE: While this monograph was in press PCA82500 was reclassified from LL6 to C4.
115
116 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE A.?Meteorites listed by source area in numerical sequence
(fractions of grams in weight dropped unless total weight is less than 1 gram).
Specimen
11 LJ.111 UC1
ALHA
76001
76002
76003
76004
76005
76006
76007
76008
76009
77001
77002
77003
77004
77005
77007**
77008**
77009
77010
77011
77012
77013**
77014
77015
77016**
77017**
77018**
77019**
77021
77022**
77023**
77025
77026**
77027**
77029**
77031**
77033
77034**
77036**
77038**
77039**
77041**
77042**
77043**
77045**
77046**
77047**
Weight
(g)
20151
1510
10495
305
1425
1137
410
1150
407000
252
235
779
2230
482
99
93
235
295
291
180
23
308
411
78
77
51
.59
16
16
21
19
20
3
1
0.5
9
1
8
18
8
16
20
11
17
7
20
Class
and
type
L6
I
L6
LL3
Eu
H6
L6
H6
L6
L6
L5
C3
H4
Sh
H5
L6
H4
H4
L3
H5
L3
H5
L3
H5
H5
H5
L6
H5
H5
H5
H5
L6
L6
C3
L3
L3
L3
L3
H5
H5
LL6
H5
L3
H5
H6
L3
%Fain
olivine
25
25
0-34
18
24
19
24
25
25
4-48
17-20
28
19.1
24.6
18
18
4-36
18
9-28
18
1-21
18.6
18.8
19.0
24.9
18
19.1
19.1
18
24.3
25.0
23.0
n.d.
8-38
n.d.
n.d.
19.0
18.5
30.7
19.0
1-37
18.7
19.0
n.d.
%Fsin
pyroxene
21
21
0-53
37-57
16
21
17
21
21
22
2-25
15-27
23
16.7
20.6
16
15-18
1-33
16
1-35
17
4-24
17.1
16.3
17.0
21.4
17
17.0
16.8
17
20.7
21.5
2.6
n.d.
8-9
n.d.
n.d.
17.1
16.3
25.1
16.6
1-28
17.0
16.7
n.d.
Degree
of
weathering
A
A
A
A
C
B
B/C
B
B
B
A
C
A
B
A
C
C
C
C
B
C
C
B
B
B/C
B/C
C
A
B
C
B/C
B/C
A/B
B/C
cB/C
B
A/B
A/B
A
A/B
B/C
A
A/B
C
Specimen
ni inn rif*T*HUH lUv 1
77049**
77050**
77051**
77052**
77054**
77056**
77058**
77060**
77061
77062
77063**
77064
77066**
77069**
77070**
77071
77073**
77074
77076**
77078**
77079**
77081
77082**
77084**
77085**
77086
77087**
77088
77089**
77091**
77092**
77094**77096**
77098**
77100**
77101**
77102
77104**77106**
77108**
77111**
77112**
77113**77114**
77115**
77117**77118
Weight
(g)
7
84
15
112
10
12
3
64
12
16
2
6
4
0.8
18
10
10
12
1
7
7
8
12
44
45
19
30
51
7
4
45
6
2
8
8
3
12
67
0.7
52
21
2
44
154
20
7
Class
and
type
L3
L3
H5
L3
H5
H4
H5
LL5
H5
H5
H5
H5
H5
L6
H5
H5
H5
H5
H5
H5
H5
H?
H5
H5
H5
H5
H5
H5
L6
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H6
H5
H5
H5
L3
L5
H5
%Fain
olivine
n.d.
n.d.
18.8
n.d.
18.5
18.8
18.8
28.1
18
18
18.0
18
19.0
25.4
18.4
18
18.8
18
19.5
19.5
18.2
11
19.3
18.8
18.8
19
19.0
19
25.5
18.9
18.5
18.518.7
18.7
19.2
18.6
19
18.918.8
18.5
19.0
18.7
18.719.6
n.d.
24.4
19
%Fsin
pyroxene
n.d.
n.d.
16.5
n.d.
16.9
16.3
16.1
23.2
17
17
16.8
17
17.4
21.4
16.8
17
17.7
17
16.1
16.7
15.8
11
16.5
16.8
17.6
17
16.7
17
21.4
16.1
16.5
16.217.1
16.7
16.4
17.0
15
16.916.5
15.9
16.6
16.7
18.417.2
n.d.
21.017
Degree
of
weathering
B/C
B/C
A
B/C
B
A/B
B
A
B
B
B
B
A
B/C
B
B
A/B
B
B
B
A
B
A/B
A/B
B
C
B
C
B
B/C
A
BA
B
A/B
B
B
AA/B
A/B
A/B
A
B
B
B/C
A/B
C
NUMBER 26 117
TABLE A.?Continued.
Specimen
nil tn h/^T"
11 U 111 U\Z1
77119
77120**
77122**
77124
77125**
77126**
77127**
77129**
77130**
77131**
77132**
77133**
77134**
77136**
77138**
77139**
77140
77142**
77143**
77144
77146**
77147**
77148
77149**
77150
77151**
77152**
77153**
77155
77156**
77157**
77158**
77159**
77160
77161**
77162**
77163**
77164
77165
77166**
77167
77168**
77170**
77171**
77173**
77174**
77175**
77176**
77177
Weight
(g)
6
3
4
4
18
25
3
1
24
25
115
18
19
3
2
65
78
3
39
7
18
18
13
25
58
16
17
12
305
17
88
19
17
70
6
29
24
38
30
138
611
24
12
23
25
32
23
54
368
Class
and
type
H5
H5
H5
H5
H5
H5
L5
H5
H5
H6
H5
H6
H6
H5
H5
H5
L3
H5
H5
H6
H6
H6
H6
H6
L6
H5
H5
H5
L6
E4
H6
H5
L6
L3
H5
L6
L3
L3
L3
L3
L3
H5
L3
H5
H5
H5
L3
L3
H5
%Fa in
olivine
18
18.5
19.1
19
17.2
18.3
25.0
18.9
18.9
19.2
19.0
19.0
18.9
19.1
19.2
18.6
8-44
18.9
18.7
19
18.9
19.0
18
19.1
25
18.9
18.7
19.2
24
0.8
18.6
18.9
24.4
3-46
19.3
25.3
n.d.
6-39
8-33
n.d.
2-41
19.0
n.d.
18.9
19.1
18.3
n.d.
0.3-34
18
%Fs in
pyroxene
17
16.0
16.8
16
15.5
16.2
21.1
16.6
16.5
16.8
16.9
17.0
16.7
16.4
17.0
16.4
2-17
17.1
16.2
17
16.9
16.6
16
16.9
22
16.4
16.9
16.7
20
1.5
15.7
16.9
20.8
6-40
17.1
20.9
n.d.
3-41
6-35
n.d.
3-17
16.5
n.d.
17.0
17.0
16.0
n.d.
1-37
16
Degree
of
weathering
C
A/B
B
C
A/B
A/B
B
B
A
A/B
A/B
A
A
A/B
A
A/B
C
A/B
A/B
B
A/B
A/B
C
A/B
C
A
A
A
A/B
A
A/B
B
A/B
C
B
A
B/C
C
C
C
C
B
B/C
A/B
B
A
B/C
B
C
Specimen
n u m oer
77178**
77180
77181**
77182
77183
77184**
77185**
77186**
77187**
77188**
77190
77191
77192
77193**
77195**
77197**
77198**
77200**
77201**
77202**
77205**
77207**
77208
77209**
77211**
77212**
77213**
77214
77215
77216
77217
77218**
77219
77220**
77221
77222**
77223
77224
77225
77226
77227**
77228**
77230
77231
77232
77233
77235**
77237**
77239**
Weight
(g)
5
190
33
1134
288
127
28
122
52
109
387
642
845
6
4
20
7
0.9
15
2
3
4
1733
31
26
16
8
2111
819
1470
413
45
637
69
229
125
207
786
5878
15323
16
19
2473
9270
6494
4087
4
4
19
Class
and
type
L3
L6
H5
H5
H6
H5
L3
H5
H5
H5
H4
H4
H4
H5
H5
L3
L6
H6
H5
H5
H5
H5
H4
H6
L3
H6
H5
L3
L3
L3
L3
L5
M
H5
H4
H4
H4
H4
H4
H4
H5
H5
L4
L6
H4
H4
H5
H5
H6
%Fa in
olivine
1-36
24
20.0
19
19
17.8
n.d.
18.8
18.1
18.1
17-19
16-18
16-18
19.0
18.9
10-27
24.4
19.7
18.8
18.6
18.8
17.8
17
18.8
n.d.
18.9
18.6
1-49
22-26
15-35
17-25
23.4
26
17.7
15
18.0
17
19
17
18
18.9
18.5
22-25
24
17
14-21
18.9
18.5
18.7
%Fs in
pyroxene
2-40
20
17.3
17
16
15.9
n.d.
16.0
16.3
16.1
15-22
14-16
15-21
15.7
16.4
4-21
20.6
17.6
15.3
16.6
16.7
16.7
14
16.4
n.d.
17.0
16.5
4-23
9-21
14-23
9-26
19.1
24-28
16.0
13-15
15.3
15-23
17
16
16
16.6
16.3
18-29
21
15
15-17
16.7
15.8
15.9
Degree
of
weathering
B/C
C
B
C
C
B
A/B
A/B
A/B
A/B
C
C
C
A
A
A/B
B
C
A
B
B
A/B
C
B
B/C
A/B
A
C
B
A/B
B
A
B
B
C
A/B
C
C
C
C
A
B
C
A/B
C
C
A/B
A
B
118 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE A.?Continued.
Specimen
number
77240**
77241**
77242**
77244**
77245**
77246**
77247**
77248**
77249
77250
77251**
77252
77253**
77254
77255
77256
77257
77258
77259
77260
77261
77262
77263
77264
77265**
77266**
77267**
77268
77269
77270
77271
77272
77273
77274
77275**
77277
77278
77279**
77280
77281
77282
77283
77284
77285
77286
77287
77288
77289
77290
Weight
(g)
25
144
56
39
33
41
44
96
503
10555
68
343
23
245
765
676
1995
597
294
744
411
861
1669
11
18
108
103
272
1045
588
609
674
492
288
24
142
312
174
3226
1231
4127
10510
376
271
245
230
1880
2186
3784
Class
and
type
H5
L3
H5
L3
H5
J6
H5
H6
L3
I
L6
L3
H5
L5
I
Di
Ur
H6
H5
L3
L6
H4
I
H5
H5
H5
L5
H5
L6
L6
H6
L6
L6
H5
H5
L6
LL3
H5
L6
L6
L6
1
L6
H6
H4
H5
H6
I
1
%Fa in
olivine
18.8
n.d.
18.8
n.d.
19.2
19.2
18.8
18.7
7-35
25.0
22-28
19.2
23
13
18
18
7-23
24
15-19
19
17.6
19.6
24.7
18
24
24
18
24
24
18
18.3
24
11-29
18.8
24
24
24
25
18
17
18
19
%Fsin
pyroxene
16.0
n.d.
16.2
n.d.
17.2
16.5
16.4
16.7
2-25
21.3
2-22
16.9
20
23
12
16
15
1-28
21
13-16
16
15.9
17.7
20.9
16
22
21
16
20
20
16
15.6
20
9-21
17.1
21
20
20
21
16
12-16
16
17
Degree
of
weathering
A
C
B
B/C
A/B
B
A/B
B/C
C
B
B
A/B
A/B
A/B
A
B/C
C
C
B
B/C
A/B
B
B
A
C
B
A/B
C
B/C
B
C
A
A/B
A
A
B
B
B
A/B
C
C
C
C
Specimen
nil nvrM^T*11 It 111 L/C 1
77291**
77292
77293**
77294
77295**
77296
77297
77299
77300
77301**
77302
77303**
77304
77305
77306
77307
78004*
78006
78015*
78019
78027*
78038
78039
78040
78042
78043
78044
78045
78047*
78048
78050
78052*
78053
78074
78075
78076
78077
78078
78081*
78084
78085
78086*
78088*
78090*
78092*
78094*
78096*
78098*
Weight
(g)
5
199
109
1351
141
963
951
260
234
55
235
78
650
6444
19
181
35
8
34
30
29
363
299
211
214
680
164
396
130
190
1045
97
179
200
280
275
330
290
17
14280
219
9
5
7
16
4
7
2
Class
and
type
H5
L6
L6
H5
E4
L6
L6
H3
H5
L6
Eu
L3
L4
L6
C2
C3
H5
Ho
LL(?L)3
Ur
H5
L3
L6
Eu
L6
L6
L4
L6
H5
L6
L6
H5
H4
L6
H5
H6
H4
L6
H5
H4
H5
H6
H5
H5
H5
H5
H5
H5
%Fa in
olivine
18.9
24
24.7
17
0.8
24
24
11-21
18
24.9
n.d.
18-27
24
1-45
1-30
19.2
8-35
22
19.3
4-42
24
24
25
23-25
25
18.8
24
23
17.9
17
24
18
18
19
24
19.1
18
18
19.0
18.8
18.7
19.0
19.1
18.9
18.9
%Fsin
Degree
of
pyroxene weathering
15.9
20
20.9
15
1.7
21
20
15-20
16
20.9
37-64
n.d.
13-19
21
1
1-12
25-61
18
2-19
21
33-52
20
21
19-24
21
21
20
16
21
16
16
15-18
20
8-24
16
A
B
B
A
B
A/B
A
A
C
A
A
B/C
B
B/C
A
A
A
B/C
C
B
A
B
B
B/C
B/C
B
A/B
B
C
C
B
B/C
B
C
A/B
B/C
B
NUMBER 26 119
TABLE A.?Continued.
Specimen
number
78100
78102
78103
78104
78105
78106
78107
78108
78109
78110
78111
78112
78113
78114
78115
78116*
78121*
78125*
78126
78127
78128
78130
78131
78132
78134
78135*
78139*
78142*
78147*
78153
78158
78160*
78165
78188
78193
78196
78209
78211
78213
78215
78221
78223
78225
78227
78229
78231
78233
78251
78252
Weight
(g)
85
336
589
672
941
464
198
172
233
160
126
2485
298
808
847
127
30
18
606
194
154
2733
268
656
458
130
17
31
30
151
15
16
20
0.9
13
11
12
11
9
6
5
6
4
2
1
1
1
1312
2789
Class
and
type
I
H5
L6
L6
L6
L6
H5
H5
LL5
H5
H5
L6
Au
L6
H6
H5
H5
L6
L6
L6
H5
L6
L6
Eu
H4
H6
H5
L5
H5,6
LL6
Eu
H5
Eu
L3
H4
H4
H5
H6
H6
H6
H5
H4
H5
H5
H6
H6
H5
L6
I
%Fain
olivine
18
24
24
23
24
18
18
28
18
18
25
0
25
18
18.7
19.2
25.0
25
24
19
25
25
18
19.0
19.3
24.2
19.4
29
19.3
1-34
18
18
18
18
18
18
18
18
18
18
18
18
18
23
%Fs in
pyroxene
17
20
20
20
20
17
16
23
16
16
20
0
20
16
21
20
17
21
21
40-68
15-20
24
40-68
37-61
5-29
16
16
15
16
15
16
16
16
16
16
15
16
16
20
Degree
of
weathering
B/C
B
B
B
A/B
C
B
A/B
B/C
B/C
B
A/B
B/C
B
B
B
B
B/C
C
B/C
B/C
A
B/C
B
B/C
A
A
C
B/C
B/C
B/C
B
B
B/C
B
B
B
B/C
B
B/C
B/C
B
Specimen
m irnHpri luinu\~ i
78261
78262
79001
79002
79003
79004
79005
79006
79007
79008
79009
79010
79011
79012
79013
79014
79015
79016
79017
79018
79019
79020
79021
79022
79023
79024
79025
79026
79027
79028
79029
79031
79032
79033
79034
79035
79036
79037
79038
79039
79040
79041
79042
79043
79045
79046
79047
79048
Weight
(g)
5
26
32
222
5
34
60
40
142
12
75
25
14
191
28
10
64
1146
310
120
12
4
29
31
68
21
1208
572
133
16
505
2
2
208
12
37
20
14
49
108
13
20
11
62
115
89
19
36
Class
and
type
C2
Ur
L3
H6
LL3
H5
H6
H5
L6
H5
H5
H5
H5
H5
H5
H5
H5
H6
Eu
L6
H6
H6
H5
L3,4
H4
H6
H5
H5
L6
H6
H5
H5
H5
L6
H6
H4
H5
H6
H5
H4
H5
H5
H5
L6
L3
H5
H5
H5
%Fa in
olivine
0-50
22
6-39
16
10-38
16
18
18
23
17
18
17
18
17
18
18
17
17
23
17
17
18
1-28
17
17
17
18
24
18
18
16
16
24
18
17
18
18
17
16
18
18
18
23
2-38
18
18
18
%Fs in
pyroxene
1-8
19
2-31
18
5-26
14
16
15
19
15
15
15
16
15
16
16
15
15
28-53
20
15
15
17
9-22
14-17
15
15
16
20
16
16
14
14
20
16
14-18
16
16
15
15
15
16
16
20
2-29
15
15
16
Degree
of
weathering
A
B/C
C
C
B
B/C
B
B/C
A/B
B
C
B/C
B/C
C
C
B
B
B/C
A
B/C
B
B/C
B
A/B
B/C
C
C
B
B
B
C
C
C
B
B
B
B
B
C
B
B
B
B
C
C
B
B
B
120 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE A.?Continued.
Specimen
number
79049
79050
79051
79052
79053
79054
79055
80101
80102
80103
80104
80105
80106
80107
80108
80110
80111
80112
80113
80114
80115
80116
80117
80118
80119
80120
80121
80122
80123
80124
80125
80126
80127
80128
80129
80130
80131
80132
80133
81001
81002
81003
81004
81005
81006
81007
81008
81009
Weight
(g)
54
27
24
22
86
36
15
8725
471
535
882
445
432
177
124
167
42
330
312
232
306
191
89
2
33
60
39
49
27
11
139
34
47
138
93
5
19
152
3
52
14
10
4
31
254
163
43
229
Class
and
type
H6
H5
H5
L6
H5
H5
H6
L6
Eu
L6
I
L6
H4
L6
L6
L6
H5
L6
L6
L6
L6
L6
L6
H6
L6
L6
H4
H6
H5
H5
L6
H6
H5
H4
H5
H6
H4
H5
L3
Eu
C2
C3
C2
A
Eu
Eu
Eu
Eu
%Fa in
olivine
18
18
18
23
17
18
18
24
24
24
19
24
24
24
18
24
24
24
24
24
24
17
24
24
19
18
18
18
24
19
18
18
18
18
19
18
1-35
0-52
0-60
0-52
11-40
%Fsin
pyroxene
16
15
15
20
15
16
16
20
34-52
20
20
16-19
20
20
20
16
20
20
20
20
20
20
15
20
20
17
16
16
16
20
17
16
15-20
15
16
16-22
16
5-30
59
0-2
1
0-2
7-47
35-60
38-55
32-59
30-63
Degree
of
weathering
C
C
c
B/C
B/C
B
B/C
B
A
B
B
C
B
B
B
B
B
B
B
B/C
B
u
MJ
B
B
B/C
B/Cc
B/C
A/B
B
B
B
B/C
B
B
B
A
A
A/B
A/B
A/B
A
A/B
A/B
A
Specimen
n I i m r^f*T1 IUI1I U\~. 1
81010
81011
81012
81013
81014
81015
81016
81017
81018
81019
81020
81021
81022
81023
81024
81025
81026
81027
81028
81029
81030
81031
81032
81033
81034
81035
81036
81037
81038
81039
81040
81041
81042
81043
81044
81045
81046
81047
81048
81049
81050
81051
81052
81053
81054
81055
81056
81057
81058
Weight
(g)
219
405
36
17727
188
5489
3850
1434
2236
1051
1352
695
912
418
797
379
515
3835
80
153
1851
1594
726
252
254
256
252
320
229
205
194
728
534
106
386
90
16
81
190
8
25
43
28
2
2
4
1
8
66
Class
and
type
Eu
Eu
Eu
I
I
H5
L6
L5
L5
H5
H5
E6
H4
L5
L3
L3
L6
L6
L6
L6
L3
L3
L3
H5
H5
H6
H5
H6
H6
H5
L4
H4
H5
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
L3
H6
H6
H4
H4
H4
%Fain
olivine
19
25
25
24
19
19
19
25
3-28
1-41
25
25
25
25
1-49
1-43
0-42
18
19
19
19
20
19
19
25
18
19
18
18
18
18
18
18
18
18
18
18
1-29
19
19
19
19
18
%Fs in
pyroxene
31-57
33-60
33-62
16
21
21
21
16
16
0-1
17
21
2-24
3-40
21
21
21
21
5-33
3-35
2-14
16
17
17
17
17
17
17
21
15-23
17
15
16
16
16
16
16
16
16
16
16
1-42
17
16
17
13-21
15
Degree
of
weathering
A
A/B
A/B
B
B
B
B
B/C
B
A
B/C
B
C
C
B
C
B
C
B/C
C
C
C
B
C
C
B
C
A/B
B/C
C
C
B/C
C
C
C
B/C
B/C
B/C
C
B/C
C
C
B
B
B
B
C
NUMBER 26 121
TABLE A.?Continued.
Specimen
number
81059
81060
81061
81062
81063
81064
81065
81066
81067
81068
81069
81070
81071
81072
81073
81074
81075
81076
81077
81078
81079
81080
81081
81082
81083
81084
81085
81086
81087
81088
81089
81090
81091
81092
81093
81094
81095
81096
81097
81098
81099
81100
81101
81102
81103
81104
81105
81106
81107
Weight
(g)
539
28
23
0.5
4
191
13
8
227
23
7
3
2
3
3
7
15
10
4
5
7
16
5
5
6
15
16
5
8
3
11
9
12
15
271
152
58
83
79
70
151
154
119
196
136
183
92
48
139
Class
and
type
M
L3
L3
H5
H5
H5
L3
L3
H5
H4
L3
H5
H5
H5
H4
H4
H5
H6
H5
H6
H6
H5
H5
H5
H5
H5
L3
H6
L3
H5
H5
H5
H5
H4
H6
H6
H4
H6
H4
M
L6
H5
Ur
H6
H6
H4
H4
L6
L6
%Fain
olivine
28
2-28
3-33
18
18
18
10-41
1-44
19
19
4-38
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
1-39
19
2-29
19
19
19
19
19
20
19
18
19
18
25
19
10-22
19
19
19
18
24
24
%Fsin
pyroxene
25-32
5-27
5-27
16
16
15
5-24
1-25
17
16
1-31
17
17
17
8-18
16
17
16
17
16
16
17
17
17
16
16
2-25
16
3-31
17
17
16
16
17
17
16
16
17
16
28
21
17
17
17
17
16
20
21
Degree
of
weathering
C
C
B/C
C
B/C
C
B/C
C
C
B
B/C
B/C
B
B/C
B/C
B
B
B
B
B/C
C
A/B
B
B
B
B
C
BB/C
B
B
B
B
B
A/B
C
B/C
B
B
C
A/B
B
A/B
B/C
B/C
C
C
B
B
Specimen
number
81108
81109
81110
81111
81112
81113
81114
81115
81116
81117
81118
81119
81120
81121
81122
81123
81124
81125
81126
81127
81136
81153
81154
81158
81251
82100
82101
BTNA
78001
78002
78004
DRPA
78001
78002
78003
78004
78005
78006
78007
78008
78009
EETA
79001
79002
79003
79004
79005
Weight
(g)
69
1
3
210
150
111
79
154
1
32
84
107
13
88
20
2
9
10
21
15
1
4
1
2
158
24
29
160
4301
1079
15200
7188
144
133
18600
389
11800
59400
138100
7942
2843
435
390
450
Class
and
type
H5
H4
H5
H6
H6
H5
H4
H5
H5
H4
H5
L4
H5
L3
L6
LL6
H5
H5
H5
H6
H5
L5
H6
H5
LL3
C2
C3
L6
L6
LL6
I
I
I
I
I
I
I
I
I
Sh
Di
L6
Eu
Eu
%Fain
olivine
18
19
19
19
19
18
18
19
19
18
19
24
18
8-40
25
30
19
19
19
19
20
24
19
19
1-29
1-47
1-50
24
24
30
23-27
24-25
24
%Fsin
pyroxene
16
17
17
17
17
16
16
17
17
14-21
16
21
16
1-24
21
25
17
17
16
17
17
21
17
17
2-28
1-2
1-10
21
20
24
16-67
22
20
30-61
30-61
Degree
of
weathering
B
B
B/C
B/C
B/C
B/C
B/C
C
B
B
B/C
B
B/C
B
B
B
B
B
B
B/C
B
B
B
B/C
B/C
A
A
B
B
B
A
B
B
B
A
122 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE A.?Continued.
Specimen
number
79006
79007
79009
79010
79011
82600
MBRA
76001
76002
META
78001
78002
78003
78005
78006
78007
78010
78028
OTTA
80301
PCA
82500
82501
82502
PGPA
77006
RKPA
78001
78002
78003
78004
79001
79002
79003
79004
79008
79009
79012
79013
79014
79015
80201
80202
80203
Weight
(g)
716
199
140
287
86
247
4108
13773
624
542
1726
172
409
174
233
20657
35
90
54
890
19068
234
8483
1276
166
3006
203
182
370
73
55
12
11
77
10022
813
544
3
Class
and
type
Ho
H5
L5
L6
Eu
Ho
H6
H6
H4
L6
L6
L6
H6
H6
H5
L6
H3
LL6
Eu
Eu
I
L6
H4
L6
H4
L6
L6
H6
H5
L3
H6
H6
L5
H5
M
H6
L6
H6
%Fa in
olivine
18
24
24
18
18
17
23
24
24
18
19
19
25
17-19
31
23
18
23
17
23
24
18
18
1-29
18
18
23
18
19
24
19
%Fsin
pyroxene
19-57
16
20
20
30-61
22-53
16
16
14-21
20
21
20
15
17
17
21
4-19
41-57
36-61
20
15
20
14-21
20
20
16
16
2-28
16
16
20
16
24
16
20
17
Degree
of
weathering
B
B
B
B
B
A
B
B
B/C
B
B
B
C
B/C
B
B
B
B
A
A
C
B
C
A
B
B
B
B/C
B
C
B
B/C
B/C
A/B
B
B
C
Specimen
number
80204
80205
80206
80207
80208
80209
80210
80211
80213
80214
80215
80216
80217
80218
80219
80220
80221
80222
80223
80224
80225
80226
80227
80228
80229
80230
80231
80232
80233
80234
80235
80236
80237
80238
80239
80240
80241
80242
80243
80244
80245
80246
80247
80248
80249
80250
80251
80252
80253
Weight
(g)
15
53
46
17
10
9
10
2
19
4
9
44
7
6
21
124
51
6
25
8
8
160
7
11
14
58
238
80
413
136
261
15
22
18
5
61
0.6
7
3
14
36
5
1
11
9
3
29
11
4
Class
and
type
Eu
H3
H6
H3
H6
L5
H5
H6
H6
H6
L6
L4
H5
H5
L6
H5
H6
LL6
H5
Eu
L6
I
H5
L5
M
H5
H6
H4
H5
LL5
LL6
H5
H4
LL6
Ur
H5
C3
L4
H5
H5
H5
M
H5
LL6
H5
H5
H5
L6
LL5
%Fa in
olivine
17-20
19
15-29
19
25
19
19
19
19
24
23
18
18
25
18
19
28
18
25
19
23
18
18
18
18
26
30
18
18
28
16
18
1-6
22
18
18
18
18
27
17
17
17
24
27
%Fs in
pyroxene
52-57
5-13
17
6-28
17
21
16
17
17
17
20
20
15
15
21
16
17
23
16
54
21
16
19
24
16
16
16
16
22
24
16
16
23
15
16
1-8
19
16
16
16
24
16
23
15
15
15
20
22
Degree
of
weathering
A
B
C
C
B
C
B/C
C
B/C
C
C
Bc
c
B
B/C
cB
cA/B
C
B/C
C
C
B
C
B
B/C
B
A/B
B/C
C
A/B
B
C
B
B/C
C
C
B/C
C
C
A/B
B/C
B/C
B
A/B
A/B
NUMBER 26 123
TABLE A.?Continued.
Specimen
number
80254
80255
80256
80257
80258
80259
80260
80261
80262
Weight
(g)
68
6
153
8
4
20
7
61
32
Class
and
type
H6
H6
L3
H5
M
E5
H5
L6
H6
%Fain
olivine
19
19
20-25
17
18
24
19
%Fsin
pyroxene
17
17
10-26
15
17-21
0-1
16
20
17
Degree
of
weathering
C
C
B
B/C
B/C
B/C
C
B
C
Specimen
nil m Y^f* T*11U111 U\Z 1
80263
80264
80265
80266
80267
80268
TIL
82403
Weight
(g)
16
23
7
9
24
3
49
Class
and
type
M
L6
H6
H6
H4
L5
Eu
%Fain
olivine
24
19
19
19
24
%Fsin
Degree
of
pyroxene weathering
24
20
17
17
16
20
43-58
C
B
C
B/C
C
B/C
A
124 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE B.?Meteorites listed by class and source area in numerical sequence
(fractions of grams weight dropped unless total weight is less than 1 gram).
Specimennumber
ALHA77306
ALHA78261
ALHA81002
ALHA81004
ALHA82100
ALHA77307
ALHA77003
ALHA77029**
ALHA82101
ALHA81003
RKPA80241
ALHA77156**
ALHA77295
RKPA80259
ALHA81021
ALHA77299
OTTA80301
RKPA80205
ALHA77004
ALHA77009
ALHA77O1O
ALHA77056**
ALHA77190
ALHA77191
ALHA77192
ALHA77208
ALHA77221
ALHA77222**
ALHA77223
ALHA77224
ALHA77225
ALHA77226
ALHA77232
ALHA77233
ALHA77262
ALHA77286
ALHA78053
ALHA78077
ALHA78084
ALHA78134
ALHA78193
ALHA78196 ,
ALHA78223
Weight
(g)
19
5
14
4
24
181
779
1
29
10
0.6
17
141
20
695
260
35
53
2230
235
295
12
387
642
845
1733
229
125
207
786
5878
15323
6494
4087
861
245
179
330
14280
458
13
11
6
Classand
type
C2
C2
C2
C2
C2
C3
C3
C3
C3
C3
C3
E4
E4
E5
E6
H3
H3
H3
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
Degree of
weathering
A
A
A
A/B
A
A
A
A/B
A
A/B
B
B
B
B/C
A
A
B/C
B
C
C
C
A/B
C
C
cc
c
A/B
C
cc
cc
c
B/C
cc
c
B/C
B/C
B/C
B/C
B
Degree of
fracturing
CHON
A
A
B
A
A
A
A
A/B
A/B
B
B
B
A
B
B
C
A
A
C
B/C
C
C
A
C
C
cc
c
B
B
B
B
B
B
B/C
A
B
B
Specimennumber
DRrTES
ALHA79023
ALHA79035
ALHA79039
ALHA80106
ALHA80121
ALHA80128
ALHA80131
ALHA81022
ALHA81041
ALHA81043
ALHA81044
ALHA81045ALHA81046
ALHA81047
ALHA81048
ALHA81049
ALHA81050ALHA81051
ALHA81052
ALHA81056
ALHA81057
ALHA81058
ALHA81068
ALHA81073
ALHA81074
ALHA81092
ALHA81095
ALHA81097
ALHA81104
ALHA81105
ALHA81109
ALHA81114
ALHA81117
META78001
RKPA78002
RKPA78004
RKPA80232
RKPA80237
RKPA80267
ALHA79004
ALHA77OO7**
ALHA77012
ALHA77014
ALHA77016**
ALHA77017**
Weight
(g)
68
37
108
432
39
138
19
912
728
106
386
90
16
81
190
8
25
43
28
1
8
66
23
3
7
15
58
79
183
92
1
79
32
624
8483
166
80
22
24
34
99
180
308
78
77
Classand
type
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H4
H5
H5
H5
H5
H5
H5
Degree of
weathering
B/C
B
B
C
B/C
B
B
B/C
C
B/C
C
C
C
B/C
B/C
B/C
C
B/C
C
B
B
C
B
B/C
B
B
B/C
B
C
C
B
B/C
B
B/C
B
A
B
C
C
B/C
B
C
C
B
B
Degree of
fracturing
C
B
B
B
C
B/C
B
A
C
C
C
B/C
B/C
B/C
B/C
B
C
B
B
A
A
C
A
A
B
A
C
A
C
B/C
A
B/C
B/C
B
A/B
A
A
B
A
B
A
B/C
NUMBER 26 125
TABLE B.?Continued
Specimennumber
ALHA77018**
ALHA77021
ALHA77022**
ALHA77O23**
ALHA77025
ALHA77038**
ALHA77039**
ALHA77042**
ALHA77045**
ALHA77051**
ALHA77054**
ALHA77058**
ALHA77061
ALHA77062
ALHA77063**
ALHA77064
ALHA77066**
ALHA77070**
ALHA77071
ALHA77073**
ALHA77074
ALHA77076**
ALHA77078**
ALHA77079**
ALHA77082**
ALHA77084**
ALHA77085**
ALHA77086
ALHA77087**
ALHA77088
ALHA77091**
ALHA77092**
ALHA77094**
ALHA77096**
ALHA77098**
ALHA77100**
ALHA771O1**
ALHA77102
ALHA77104**
ALHA77106**
ALHA77108**
ALHA77112**
ALHA77113**
ALHA77114**
ALHA77118
ALHA77119
ALHA77120**
ALHA77122**
Weight
(g)
51
16
16
21
19
18
8
20
17
15
10
3
12
16
2
6
4
18
10
10
12
1
7
7
12
44
45
19
30
51
4
45
6
2
8
8
3
12
6
7
0.7
21
2
44
7
6
3
4
Classand
type
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
i*- be
Degree o
weatherin
B/C
C
A
B
C
A/B
A/B
A/B
A
A
B
B
B
B
B
B
A
B
B
A/B
B
B
B
A
A/B
A/B
B
C
B
C
B/C
A
B
A
B
A/B
B
B
A
A/B
A/B
A
B
B
C
C
A/B
B
Degree o
fracturinj
A
B
A
B
B
B
B
B
B
B
B
B
Specimennumber
ALHA77124
ALHA77125**
ALHA77126**
ALHA77129**
ALHA77130**
ALHA77132**
ALHA77136**
ALHA77138**
ALHA77139**
ALHA77142**
ALHA77143**
ALHA77151**
ALHA77152**
ALHA77153**
ALHA77158**
ALHA77161**
ALHA77168**
ALHA77171**
ALHA77173**
ALHA77174**
ALHA77177
ALHA77181**
ALHA77182
ALHA77184**
ALHA77186**
ALHA77187**
ALHA77188**
ALHA77193**
ALHA77195**
ALHA77201**
ALHA77202**
ALHA772O5**
ALHA77207**
ALHA77213**
ALHA77220**
ALHA77227**1
ALHA77228**
ALHA77235**
ALHA77237**
ALHA77240**
ALHA77242**
ALHA77245**
ALHA77247**
ALHA77253**
ALHA77259
ALHA77264
ALHA77265**
ALHA77266**
Weight
(g)
4
18
25
1
24
115
3
2
65
3
39
16
17
12
19
6
24
23
25
32
368
33
1134
127
122
52
109
6
4
15
2
3
4
8
69
16
19
4
4
25
56
33
44
23
294
11
18
108
Classand
type
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
i*- bo
Degree o
weatherin
C
A/B
A/B
B
A
A/B
A/B
A
A/B
A/B
A/B
A
A
A
B
B
B
A/B
B
A
C
B
C
B
A/B
A/B
A/B
A
A
A
B
B
A/B
A
B
A
B
A/B
A
A
B
A/B
A/B
A/B
C
A/B
B
B
Degree o
fracturinj
A
A
B
B
A
126 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE B.?Continued
Specimennumber
ALHA77268
ALHA77274
ALHA77275**
ALHA77279**
ALHA77287
ALHA77291**
ALHA77294
ALHA773OO
ALHA78004*
ALHA78027*
ALHA78047*
ALHA78052*
ALHA78075
ALHA78081*
ALHA78085
ALHA78088*
ALHA78090*
ALHA78092*
ALHA78094*
ALHA78096*
ALHA78098*
ALHA78102
ALHA78107
ALHA78108
ALHA78110
ALHA78111
ALHA78116*
ALHA78121*
ALHA78128
ALHA78139*
ALHA78160*
ALHA78209
ALHA78221
ALHA78225
ALHA78227
ALHA78233
ALHA79006
ALHA79008
ALHA79009
ALHA79010
ALHA79011
ALHA79012
ALHA79013
ALHA79014
ALHA79015
ALHA79021
ALHA79025
ALHA79026
Weight
(g)
272
288
24
174
230
5
1351
234
35
29
130
97
280
17
219
5
7
16
4
7
2
336
198
172
160
126
127
30
154
17
16
12
5
4
2
1
40
12
75
25
14
191
28
10
64
29
1208
572
Classand
type
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
t4_, be
gree o itheriri
Q %
C
C
A
A
C
A
A
C
B
C
B/C
B
B/C
C
B
B/C
B/C
B
C
B/C
B
B
B/C
B/C
B/C
B
C
B/C
B/C
C
C
B
B
B
C
B
<*- bo0 g
E 3
be <j<u a
C
A
A
A
B
B
B
B
B
B
A
B
B
A
B
B/C
B
A
A
B
B
B
B
A
B
A
B
B
A
B
A
A
B
Specimennumber
ALHA79029
ALHA79031
ALHA79032
ALHA79036
ALHA79038
ALHA79040
ALHA79041
ALHA79042
ALHA79046
ALHA79047
ALHA79048
ALHA79050
ALHA79051
ALHA79053
ALHA79054
ALHA80111
ALHA80123
ALHA80124
ALHA80127
ALHA80129
ALHA80132
ALHA81015
ALHA81019
ALHA81020
ALHA81033
ALHA81034
ALHA81036
ALHA81039
ALHA81042
ALHA81062
ALHA81063
ALHA81064
ALHA81067
ALHA81070
ALHA81071
ALHA81072
ALHA81075
ALHA81077
ALHA81080
ALHA81081
ALHA81082
ALHA81083
ALHA81084
ALHA81088
ALHA81089
ALHA81090
ALHA81091
ALHA81100
Weight
(g)
505
2
2
20
49
13
20
11
89
19
36
27
24
86
36
42
27
11
47
93
152
5489
1051
1352
252
254
252
205
534
0.5
4
191
227
3
2
3
15
4
16
5
5
6
15
3
11
9
12
154
Class
and
type
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
u- be
0 _C
u 'C
C
cc
B
C
B
B
B
B
B
B
C
C
B/C
B
B
C
B
B
B
B
B
B/C
B
C
B
C
A/B
C
C
B/C
C
C
B/C
B
B/C
B
B
A/B
B
B
B
B
B
B
B
B
B
<*f bo
gree o cturin
v a
QiB/C
B
B
B
B
A
B
A
B
B
B
B
A
B
A
A
A
B
A
A
B
B
B
A
C
B
A
B
C
A
B
A/B
B
A
A
A
A
A
A
A
A
A
A
A
A
A
B
A
NUMBER 26 127
TABLE B.?Continued
Specimennumber
ALHA81108
ALHA81110
ALHA81113
ALHA81115
ALHA81116
ALHA81118
ALHA81120
ALHA81124
ALHA81125
ALHA81126
ALHA81136
ALHA81158
EETA79007
META78010
RKPA79004
RKPA79014
RKPA80210
RKPA80217
RKPA80218
RKPA80220
RKPA80223
RKPA80227
RKPA80230
RKPA80233
RKPA80236
RKPA80240
RKPA80243
RKPA80244
RKPA80245
RKPA80247
RKPA80249
RKPA80250
RKPA80251
RKPA80257
RKPA80260
ALHA78147*
ALHA76006
ALHA76008
ALHA77046**
ALHA77111**
ALHA77131**
ALHA77133**
ALHA77134**
ALHA77144
ALHA77146**
ALHA77147**
ALHA77148
Weight
(g)
69
3
111
154
1
84
13
9
10
21
1
2
199
233
370
77
10
7
6
124
25
7
58
413
15
61
3
14
36
1
9
3
29
8
7
30
1137
1150
7
52
25
18
19
7
18
18
13
Classand
type
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5
H5, 6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
u- be
Degree o
weatherin
B
B/C
B/C
C
B
B/C
B/C
B
B
B
B
B/C
B
B
B/C
B/C
B/C
C
C
B/C
C
B/C
B
B/C
B/C
C
C
C
B/C
C
B/C
B/C
B
B/C
C
C
B/C
A/B
A/B
A/B
A
A
B
A/B
A/B
C
Degree o
fracturinj
B
A
C
A/B
A
A
B
A
A
A
A/B
A
B
A
B
B
B
A
A
B/C
B
A
B
B
B
A
A
B
B
B
A
A
B
B
B
B
B
A
B
Specimennumber
ALHA77149**
ALHA77157**
ALHA77183
ALHA77200**
ALHA77209**
ALHA77212**
ALHA77239**
ALHA77246**
ALHA77248**
ALHA77258
ALHA77271
ALHA77285
ALHA77288
ALHA78076
ALHA78086*
ALHA78115
ALHA78135*
ALHA78211
ALHA78213
ALHA78215
ALHA78229
ALHA78231
ALHA79002
ALHA79005
ALHA79016
ALHA79019
ALHA79020
ALHA79024
ALHA79028
ALHA79034
ALHA79037
ALHA79049
ALHA79055
ALHA80118
ALHA80122
ALHA80126
ALHA80130
ALHA81035
ALHA81037
ALHA81038
ALHA81054
ALHA81055
ALHA81076
ALHA81078
ALHA81079
ALHA81086
ALHA81093
ALHA81094
Weight
(g)
25
88
288
0.9
31
16
19
41
96
597
609
271
1880
275
9
847
130
11
9
6
1
1
222
60
1146
12
4
21
16
12
14
54
15
2
49
34
5
256
320
229
2
4
10
5
7
5
271
152
Classand
type
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
tw bo
Degree o
weatherin
A/B
A/B
C
C
B
A/B
B
B
B/C
B/C
C
C
C
B
B
B
B
B
B/C
B
B/C
C
B
B/C
B
B/C
C
B
B
B
C
B/C
B
B/C
A/B
B/C
C
B
C
B
B
B
B/C
C
B
A/B
C
4- be
Degree o
fracturin
A
A/B
A
B
B
B
A
B
B
B
B
B
B
B
B
B
A
B
B
B
A
B
B
B
A
B
A
A
A/B
A
B
B
A
A
B
A
B
A/B
B
128 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE B.?Continued
Specimen
number
ALHA81096
ALHA81102
ALHA81103
ALHA81111
ALHA81112
ALHA81127
ALHA81154
MBRA76001
MBRA76002
META78006
META78007
RKPA79003
RKPA79009
RKPA79012
RKPA80201
RKPA80203
RKPA80206
RKPA80208
RKPA80211
RKPA80213
RKPA80214
RKPA80221
RKPA80231
RKPA80254
RKPA80255
RKPA80262
RKPA80265
RKPA80266
ALHA77081
ALHA/7011
ALHA77013**
ALHA77015
ALHA77031**
ALHA77033
ALHA77034**
ALHA77036**
ALHA77043**
ALHA77047**
ALHA77049**
ALHA77050**
ALHA77052**
ALHA77115**
ALHA77140
ALHA77160
ALHA77163**
ALHA77164
ALHA77165
Weight
(g)
83
196
136
210
150
15
1
4108
13773
409
174
182
55
12
813
3
46
10
2
19
4
51
238
68
6
32
7
9
8
291
23
411
0.5
9
1
8
11
20
7
84
112
154
78
70
24
38
30
Class
and
type
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H6
H?
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
Degree of
weathering
B
B/C
B/C
B/C
B/C
B/C
B
B
B
C
B/C
B
C
B
B
C
C
B
C
B/C
C
C
C
C
C
C
C
B/C
B
C
B
C
B/C
C
B/C
B
B/C
C
B/C
B/C
B/C
B/C
C
C
B/C
C
C
Degree of
fracturing
B
A/B
B/C
B
A
B
B
B
B
B
B
A
B
B
A
A
B
A
B
B
B
B/C
B/C
B/C
B
B
B
B
A
A
B
B
B
B
C
C
Specimen
number
ALHA77166**
ALHA77167
ALHA7717O**
ALHA77175**
ALHA77176**
ALHA77178**
ALHA77185**
ALHA77197**
ALHA77211**
ALHA77214
ALHA77215
ALHA77216
ALHA77217
ALHA77241**
ALHA77244**
ALHA77249
ALHA77252
ALHA77260
ALHA77303**
ALHA78038
ALHA78188
ALHA79001
ALHA79045
ALHA80133
ALHA81024
ALHA81025
ALHA81030
ALHA81031
ALHA81032
ALHA81053
ALHA81060
ALHA81061
ALHA81065
ALHA81066
ALHA81069
ALHA81085
ALHA81087
ALHA81121
RKPA79008
RKPA80207
RKPA80256
ALHA79022
ALHA77230
ALHA77304
ALHA78044
ALHA81040
ALHA81119
Weight
(g)
138
611
12
23
54
5
28
20
26
2111
819
1470
413
144
39
503
343
744
78
363
0.9
32
115
3
797
379
1851
1594
726
2
28
23
13
8
7
16
8
88
73
17
153
31
2473
650
164
194
107
Class
and
type
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3
L3,4
L4
L4
L4
L4
L4
Degree of
weathering
C
C
B/C
B/C
B
B/C
A/B
A/B
B/C
C
B
A/B
B
C
B/C
C
B
C
B/C
C
C
C
C
B
C
C
B/C
C
C
C
C
B/C
B/C
C
B/C
C
B/C
B
B
C
B
A/B
C
B
B/C
B/C
B
Degree of
fracturing
B/C
C
B/C
B/C
B/C
C
C
C
C
B
A
B
B
B
B
B/C
B/C
A
B
B
A
B
B
A
B
B
B
B
B
A
B
B
B
B
A
B
NUMBER 26 129
TABLE B.?Continued
Specimen
number
RKPA80216
RKPA80242
ALHA77002
ALHA77117**
ALHA77127**
ALHA77218**
ALHA77254
ALHA77267**
ALHA78142**
ALHA81017
ALHA81018
ALHA81023
ALHA81153
EETA79009
RKPA79013
RKPA80209
RKPA80228
RKPA80268
ALHA76001
ALHA76003
ALHA76OO7
ALHA76009
ALHA77001
ALHA77008**
ALHA77019**
ALHA77026**
ALHA77027**
ALHA77069**
ALHA77089**
ALHA77150
ALHA77155
ALHA77159**
ALHA77162**
ALHA77180
ALHA77198**
ALHA77231
ALHA77251**
ALHA77261
ALHA77269
ALHA77270
ALHA77272
ALHA77273
ALHA77277
ALHA77280
ALHA77281
ALHA77282
ALHA77284
Weight
(g)
44
7
235
20
3
45
245
103
31
1434
2236
418
4
140
11
9
11
3
20151
10495
410
407000
252
93
59
20
3
0.8
7
58
305
17
29
190
7
9270
68
411
1045
588
674
492
142
3226
1231
4127
376
Class
and
type
L4
L4
L5
L5
L5
L5
L5
L5
L5
L5
L5
L5
L5
L5
L5
L5
L5
L5
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
tw be
Degree o
weatherin
B
B/C
B
A/B
B
A
A/B
A
B
B
B
B
B
B/C
C
C
B/C
A
A
B
B
B
A
B/C
B/C
B/C
B/C
B
C
A/B
A/B
A
C
B
A/B
B
B
B
A/B
B/C
B
A/B
B
B
B
A/B
Degree o
fracturinj
B
B
A/B
A
A
B
A/B
A
B
B
B
B
B
A
A
A
B
B
B
A
A
A/B
B
A
B
B
B
A
B/C
B
B
B
Specimen
number
ALHA77292
ALHA77293**
ALHA77296
ALHA77297
ALHA77301**
ALHA77305
ALHA78039
ALHA78042
ALHA78043
ALHA78045
ALHA78048
ALHA78050
ALHA78074
ALHA78078
ALHA78103
ALHA78104
ALHA78105
ALHA78106
ALHA78112
ALHA78114
ALHA78125*
ALHA78126
ALHA78127
ALHA78130
ALHA78131
ALHA78251
ALHA79007
ALHA79018
ALHA79027
ALHA79033
ALHA79043
ALHA79052
ALHA80101
ALHA80103
ALHA80105
ALHA80107
ALHA80108
ALHA80110
ALHA80112
ALHA80113
ALHA80114
ALHA80115
ALHA80116
ALHA80117
ALHA80119
ALHA80120
ALHA80125
ALHA81016
Weight
(g)
199
109
963
951
55
6444
299
214
680
396
190
1045
200
290
589
672
941
464
2485
808
18
606
194
2733
268
1312
142
120
133
208
62
22
8725
535
445
177
124
167
330
312
232
306
191
89
33
60
139
3850
Class
and
type
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
IH be
Degree o
weatherin
B
B
A/B
A
A
B/C
B
B
B
B/C
A/B
B
B
A/B
B
B
B
A/B
B
B/C
B
B
B/C
B/C
B/C
B
A/B
B/C
B
B
C
B/C
B
B
B
B
B
B
B
B
B
B
B/C
B
B
B
B/C
B
Degree o
fracturin|
A
A
B
B
B
A
B
B
B
B
B
A
B
A
A
A
B
B
B
B
B
B
A
A
B
A/B
A
A
B
B
B
A
B
B
B
B
B
B/C
B
A
B
A
B
B
B
A
130 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE B.?Continued
Specimennumber
ALHA81026
ALHA81027
ALHA81028
ALHA81029
ALHA81099
ALHA81106ALHA81107
ALHA81122
BTNA78001
BTNA78002
EETA79003
EETA79010
META78002
META78003
META78005
META78028
RKPA78001
RKPA78003
RKPA79001
RKPA79002
RKPA80202
RKPA80215
RKPA80219
Weight
(g)
515
3835
80
153
151
48
139
20
160
4301
435
287
542
1726
172
20657
234
1276
3006
203
544
9
21
Classand
type
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
L6
Degree of
weathering
B
C
B
C
A/B
B
B
B
B
B
B
B
B
B
B
B
C
C
B
B
B
C
B
Degree of
fracturing
A
A/B
B
A
A
B
A
B
B
A
B
C
A
B
B
B
B
B
C
B
A
B
A
Specimennumber
RKPA80225
RKPA80252
RKPA80261
RKPA80264
ALHA78015*
ALHA76004
ALHA77278
ALHA79003
ALHA81251
ALHA77060**
ALHA78109
RKPA80234
RKPA80253
ALHA77041**
ALHA78153
ALHA81123
BTNA78004
PCA82500
RKPA80222
RKPA80235
RKPA80238
RKPA80248
Weight
(g)
8
11
61
23
34
305
312
5
158
64
233
136
4
16
151
2
1079
90
6
261
18
11
Class
and
type
L6
L6
L6
L6
LL(?L)3
LL3
LL3
LL3
LL3
LL5
LL5
LL5
LL5
LL6
LL6
LL6
LL6
LL6
LL6
LL6
LL6
LL6
Degree of
weathering
C
A/B
B
B
A
A
B
B/C
A
A/B
B
A/B
A
B/C
B
B
B
B
A/B
A/B
A/B
Degree of
fracturing
A
A
A
B
A
A
B
B
A
B
A
B
A
A
C
B
B
A
A
Subtotals:
Total:
Class and type
C2
C3
E5
E6
E4
H3
H4
H5
H5,6
H6
H?
L3
L3,4
L4
L5
L6
LL(L)3
LL3
LL5
LL6
Class 'weight (g)
66
1000
20
695
158
348
69549
25301
30
31453
8
20667
31
3637
5385
53889
34
780
437
1634
215122
NUMBER 26 131
TABLE B.?Continued
Specimennumber
ALHA81005
ALHA78113
ALHA77256
EETA79002
ALHA76005
ALHA77302
ALHA78040
ALHA78132
ALHA78158
ALHA78165
ALHA79017
ALHA80102
ALHA81001
ALHA81006
ALHA81007
ALHA81008
ALHA81009
ALHA81010
ALHA81011
Weight
(g)
31
298
676
2843
1425
235
211
656
15
20
310
471
52
254
163
43
229
219
405
Classand
type
Anorthositic
breccia
Au
Di
Di
Eu (polymict)
Eu (polymict)
Eu (polymict)
Eu (polymict)
Eu (polymict)
Eu (polymict)
Eu (polymict)
Eu (polymict)
Eu (anomalous)
Eu (polymict)
Eu (polymict)
Eu (polymict)
Eu
Eu (polymict)
Eucritic breccia
(*. bo
Degree o
weatherin
A/B
A/B
A/B
B
A
A
A
A
A
A
A
A
A
A
A/B
A/B
A
A
A/B
UH he
Degree o
fracturinj
Specimennumber
ACHONDRITES
A
A
A
B
A
A
A
A
A
A
A
B
B
A/B
A
A/B
A
A
A
ALHA81012
EETA79004
EETA79005
EETA79011PCA82501
PCA82502
RKPA80204
RKPA80224
TIL82403
ALHA78006
EETA79006
EETA82600
ALHA77005
EETA79001
ALHA77257
ALHA78019
ALHA78262
ALHA81101
RKPA80239
Weight
(g)
36
390
450
86
54
890
15
8
49
8
716
247
482
7942
1995
30
26
119
5
Classand
type
Eu
Eu
Eu (polymict)
Eu (polymict)Eu (unbrecciated)
Eu (unbrecciated)
Eu
Eu (unbrecciated)
Eu (brecciated)
Ho
Ho
Ho
Sh
Sh
Ur
Ur
Ur
Ur
Ur
tw be
Degree o
weatheriri
A/B
B
A
B
A
A
A
A/B
A
A
B
A
A
A
A
B/C
B/C
A/B
B
<*- he
Degree o
fracturinj
A
B
B
B
A
A
A
A
A
A
B
B
A
A
B
C
A
B
B
Subtotals:
Total:
Class and type
Anorthositic
breccia
Aubrite
Diogenite
Eucrite
Howardite
Shergottite
Ureilite
Class weight (g)
31
298
3519
6686
971
8424
2175
22104
ALHA81013
ALHA81014
ALHA80104
ALHA77255
ALHA76002
17727 Hexahedrite
188 Octahedrite
882 Ataxite
765 Ataxite (anom)
1510 IA
IRONS
ALHA77250
ALHA77263
ALHA77283
ALHA77289
ALHA77290
10555 IA
1669 IA
10510 IA
2186 IA
3784 IA
132 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE B.?Continued
Specimen
number
PGPA77006
ALHA78100
DRPA78001
DRPA78002
DRPA78003
DRPA78004
DRPA78005
ALHA81098
ALHA77219
ALHA81059
RKPA79015
RKPA80229
Weight
(g)
19068
85
15200
7188
144
133
18600
70
637
539
10022
14
Class
and
type
IA
IIA
IIB
IIB
IIB
IIB
IIB
M
M
M
M
M
IH bo
Degree o
weatherin
C
B
C
A/B
C
<+* ho
Degree o
fracturini
Specimen
number
DRPA78006
DRPA78007
DRPA78OO8
DRPA78009
ALHA78252
RKPA80226
Total:
STONY-IRONS
B/C
B
B/C
A
B/C
RKPA80246
RKPA80258
RKPA80263
Total:
Weight
(g)
389
11800
59400
138100
2789
160
322832
5
4
16
11307
Class
and
type
IIB
IIB
IIB
IIB
IVA
Octahedrite
M
M
M
<+. be
Degree o
weatherin
C
B/C
C
Degree o
fracturinj
C
B
B
NUMBER 26 133
TABLE C.?Meteorites from common falls tentatively identified as paired specimens (t = field
relations; v = physical similarities; w = petrographic similarities; x = metallography; y = bulk
chemistry; z = trace element chemistry).
Pair no. Paired specimens Criteria
EUCRITES
1 ALHA76005, 77302, 78040, 78132, 78158, 78165, 79017, 80102, v, w
81006,81007,81008,81010
2 ALHA81009, 81012 v, w
UREILITES
3 ALHA78019, 78262 v, w
C2 CHONDRITES
4 ALHA77306, 78261,81002, 81004 w
L3 CHONDRITES
5 ALHA77011, 77015, 77031, 77033, 77034, 77036, 77043, 77047, w
77049, 77050, 77052, 77115, 77140, 77160, 77163,77164,77165,
77166, 77167, 77170, 77175, 77178, 77185, 77211, 77214, 77241,
77244, 77249, 77260, 77303, 78038, 78188, 79001, 79045, 80133,
81025, 81030, 81031, 81032, 81053, 81060, 81061, 81065, 81066,
81069,81085,81087,81121
6 ALHA77215, 77216, 77217, 77252 t, v, w
L4 CHONDRITES
7 RKPA80216, 80242 w
L5 CHONDRITES
8 ALHA81017,81018, 81023 w
L6 CHONDRITES
9 ALHA77001, 77150, 77180, 77292, 77293, 77296, 77297, 77305 t, v, w
10 ALHA77231, 77269, 77270, 77272, 77273, 77277, 77280, 77281, t, v, w
77282,77284
11 ALHA78043, 78045 w
12 ALHA78103, 78104, 78105 t, w
13 ALHA78112, 78114 w
14 ALHA78126, 78130, 78131 w
15 ALHA78105, 78251 v
16 ALHA80101, 80103, 80105, 80107, 80108, 80110, 80112, 80113, v, w
80114,80115, 80116, 80117, 80119, 80120, 80125
17 ALHA81027, 81028, 81029 w
18 BTNA78001,78002 v, w
19 RKPA78001, 78003, 79001, 79002, 80202, 80219, 80225, 80252, w
80261,80264
LL3 CHONDRITES
20 ALHA76004,81251 w
LL6 CHONDRITES
21 RKPA80222, 80238, 80248 w
134 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES
TABLE C.?Continued
Pair no. Paired specimens Criteria
H4 CHONDRITES
ALHA77004, 77190, 77191, 77192, 77208, 77222, 77223, 77224,
77225,77226,77232,77233
ALHA78084, 81022
ALHA78193, 78196, 78223
ALHA81041, 81043, 81044, 81045, 81046, 81047, 81048, 81049,
81050,81051, 81052
H5 CHONDRITES
ALHA77014, 77264
ALHA77021, 77025, 77061, 77062, 77064, 77071, 77074, 77086,
77088, 77102
ALHA77118, 77119, 77124
ALHA78209, 78221, 78225, 78227, 78233
ALHA79031,79032
ALHA80111, 80124, 80127, 80129, 80132
RKPA80217, 80218
RKPA80220, 80223
RKPA80250, 80251
H6 CHONDRITES
ALHA77144, 77148
ALHA77271, 77288
ALHA78211, 78213, 78215, 78229, 78231
ALHA80122, 80126, 80130
ALHA81035, 81038, 81103, 81112
RKPA80203, 80206, 80208, 80211, 80213, 80214, 80221, 80231,
80254, 80255, 80262,80265,80266
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
ALHA77156, 77295
E4 CHONDRITES
M ESOSIDERITES
t, w
w
t, X
w
t
t, w
t
t, X
w
w
w
w
w
t
t
t, X
w
w
w
ALHA81059, 81098 w
RKPA79015, 80229, 80246, 80258, 80263 w
IRONS
ALHA76002, 77250, 77263, 77289, 77290 t, x, y, z
DRPA78001, 78002, 78003, 78004, 78005, 78006, 78007, 78008, t, v, x, y
78009