Mare ridges and related studies: Part D: small structures of the Taurus-Littrow region

Apollo 17 permission geologic studies of the Taurus-Littrow region of the Moon revealed numerous small structures, in both mare and terra, having somewhat similar morphologies and variously resembling fault scarps, flow fronts, and mare ridges. Many of these features are too small to be identified on Lunar Orbiter IV photographs, which provided the most comprehensive, high-resolution coverage of this area before the later Apollo missions. The panoramic- and metric-camera photographs of Apollo 17 were taken at lower Sun angles than those of Apollo 15, which were used for the geologic mapping (refs. 31-40 and 31-41), and thus more clearly reveal fine details of texture and relief. In the illustrations of this part, several of these small structures are compared. It is concluded that they probably developed as lava extrusions from fractures and fissures; they cannot be easily explained by faulting.