Evidence of Recent Thrust Faulting on the Moon Revealed by the Lunar Reconnaissance Orbiter Camera

Abstract

Lunar Reconnaissance Orbiter Camera images reveal previously undetected lobate thrust-fault scarps and associated meter-scale secondary tectonic landforms that include narrow extensional troughs or graben, splay faults, and multiple low-relief terraces. Lobate scarps are among the youngest landforms on the Moon, based on their generally crisp appearance, lack of superposed large-diameter impact craters, and the existence of crosscut small-diameter impact craters. Identification of previously known scarps was limited to high-resolution Apollo Panoramic Camera images confined to the equatorial zone. Fourteen lobate scarps were identified, seven of which are at latitudes greater than {+/-}60{degrees}, indicating that the thrust faults are globally distributed. This detection, coupled with the very young apparent age of the faults, suggests global late-stage contraction of the Moon.