USGS1971
This geologic map has been prepared from the photographic data returned by Ranger VII and is one of a series prepared from the data returned by the Ranger VII, VIII, and IX spacecraft. The map area, in Mare Cognitum, includes the Ranger VII impact point. The map shows the geologic relationship of surface units at the distal end of a ray from either the crater Tycho (Shoemaker, 1965, p. 86) or the crater Copernicus (U.S. Geol. Survey, 1971). None of the craters nor the surface detail have been resolved on Earth-based photographs; the map area appears as only a faintly bright spot on high-quality full-Moon photographs. The oldest materials recognized are those which once formed the level mare surface. These materials have been comminuted by impact and modified by shock, radiation, solar wind, and temperature effects. They are interpreted to have originally been volcanic. Superposed on the mare material is a cluster of elongate craters (unit ce). The topographic forms and surface characteristics of this unit appears to be contiguous with a belt of the south of similar forms and characteristics. In the map area, parallel to subparallel north-trending subdued craters and very gentle depressions, generally deepest and most pronounced at their north ends, are the most conspicuous landforms. They lack prominent rims and are not as distinct as typical circular craters of the same size. Their floors are irregular in profile, and walls are gently sloping. This form, the consistent alignment of the elongated craters, and the fact the belt of elongated craters extends to the south suggest the impact of a group of objects traveling at low velocities and low trajectory angles after ejection from Tycho, about 1,000 km to the south.