Impact Crater with Traces of Tectonic Deformation in the South Polar Region of the Moon

Abstract—: The work examines the structure of a crater with a diameter of 34 km, located on the mainland in the marginal zone of the south polar region of the Moon within the South Pole–Aitken impact basin. This crater belongs to the Dawes morphological type, which is characterized by a generally flattened, and in detail uneven, hilly-ridge bottom surface. The crater under study has a fractured bottom, which is considered a sign of magma intrusion into the subcrater space. Cracks in the bottom material are represented by hollows from 2 to 10 km long, 0.3–1 km wide and 50–150 m deep. The LROCNAC images show that in the hilly-ridge areas of the bottom the regolith surface has a “wrinkled” texture, and in the subhorizontal areas it is smooth. On one of the sections of the bottom there is a 700-meter crater, the rim of which touches one of the hollows. Judging by the morphology of this crater and the absence of meter-sized stones on its shaft, it was formed in the range of (200–300) million to 1 billion years ago, while the age of the studied 34-kilometer crater is estimated from the density of small craters superimposed on its rim as 3.83 (+0.025; –0.031) billion years. The age of the surface material of the deformed bottom of the crater under study is in the range of (200–300) million to 1 billion years. Probably, the fracturing of the bottom (formation of hollows) was caused by the penetration of an intrusive body or bodies into the subcrater space during the Copernican or early Eratosthenesian periods of the geological history of the Moon. The 34-kilometer crater in question certainly deserves further study.