Geologic map of the Clavius Quadrangle of the Moon
The Clavius quadrangle is in the southern lunar highlands about 500 km south of the Mare Nubium and 150 km south of the large young crater Tycho. This part of the M oon is characterized by densely cratered topography and the absence of mare materials. Geologic units in the quadrangle cannot be directly correlated with those in the vicinity of Mare Imbrium , 2500 km to the north, which define most of the lunar time-stratigraphic systems (Shoemaker and Hackman, 1962 ; Wilhelms , 1970). However, the relative ages of rock units, including crater materials, have been determined by established geologic methods, such as superposition and cross-cutting relations. In addition, crater materials have been positioned within the lunar time stratigraphic framework ( Offield , 1971) by estimates. Based on morphology, of their state of erosion ( Pohn and Offi e ld , 1970).