Abstract:
The Kinney Brick Quarry is a world famous Late Pennsylvanian fossil Lagerstatte in central New Mexico, USA. The age assigned to the Kinney Brick Quarry (early-middle Virgilian) has long been based more on its inferred lithostratigraphic position than on biostratigraphic indicators at the quarry. We have developed three datasets-stratigraphic position, fusulinids and conodonts-that indicate the Kinney Brick Quarry is older, of middle Missourian (Kasimovian) age. Our detailed local lithostratigraphic studies coupled with regional stratigraphic investigations indicate the Kinney Brick Quarry is in the Tinajas Member of the Atrasado Formation, so it is stratigraphically lower than suggested by previously published maps. A laterally extensive fusulinid-bearing limestone a few meters below the level of the Kinney Brick Quarry yields an early-middle Missourian fusulinid assemblage consisting of Tumulotriticites cf. T tumidus and species of Triticites: T. cf. T. planus, T. cf. T. myersi and T. ex gr. T. ohioensis. The Kinney conodont fauna is characterized by Idiognathodus corrugatus and I. cherryvalensis, which suggest an assignment to the Idiognathodus confragus Zone of the North America Midcontinent region (Dennis cyclothem; middle Missourian). Nonmarine biostratigraphic indicators at the Kinney Brick Quarry indicate either an imprecise age (Late Pennsylvanian: megaflora) or a slightly younger age (late Kasimovian-early Gzhelian: blattids) than do stratigraphic position and marine microfossils. The well-established age of Kinney on the marine timescale thus can be used to better calibrate the nonmarine biostratigraphy. So, the insect biozonation of the Euramerican continental basins, which was calibrated to the so-called regional West European Carboniferous stages by macrofloras and to the global marine scale by sparse, ambiguous isotopic ages, can now be linked directly to the marine conodont zonation.
