Geologic map of the Memnonia Quadrangle of Mars

The Memnonia quadrangle lies astride the boundary between heavily cratered and sparsely cratered hemispheres of Mars (Carr and others, 1973). Densely cratered terrain occurs in the southwestern part of the quadrangle. Strips of plains material bound the cratered terrain in both the northern and eastern parts of the quadrangle. There is approximately 3 km of relief across the quadrangle, with the highest elevations in the eastern part. Plains materials of this region are situated along the lower slopes of the Tharsis Montes, which continue to rise in elevation eastward into the adjacent Pheonicis Lacus and Tharsis quadrangle. There is little correlation between terrain types and elevation within the Mamnonia quadrangle. In particular, the boundary between cratered terrain and plains for the most part is not marked by any prominent change in elevation.