Geologic map of the Amenthes Quadrangle of Mars

The Amenthes quadrangle includes two main physiographic and geologic subdivisions. In the southern part of the quadrangle, densely cratered plateaus rise about 3 km above sparsely to moderately cratered plains. The low plains that form Elysium Planitia also build the eastern flank of the Isidis basin, which mostly lies with the adjacent Syrtis Major quadrangle to the west: the Elysium region, one of the main volcanic centers of Mars, is located to the east. Some of the geologic and tectonic units in the Amenthes quadrangle are related to this volcanic and uplifted zone. 

Geologic mapping is based mainly on morphological criteria together with some albedo, superposition, and crater-density data from both high- and low- resolution Mariner 9 images. Interpretations of rock units were made by comparison with well-known geologic features on the Earth and the Moon. To determine the absolute ages of map units, crater-counting methods in connection with an updated version of the crater-frequency curve of Neukem and Wise (1976) (fig. 1) were used. However, the application of this method in the Amenthes region is limited by the low resolution and lack of optimum image quantity.