Geologic map of the Argyre quadrangle of Mars

The geology of the Argyre quadrangle of Mars is dominated by the conspicuous Argyre basin, defined by a rim of rugged mountain blocks that surrounds a nearly circular expanse of plains 800 km across. Of the large (greater than 500 km in diameter) basins identified on Mars, Argyre is the best preserved and probably the youngest. Basins appear to be traps for eolian debris and evidently are source areas for some of the dust storms that periodically envelop the planet. The quadrangle lies within the densely cratered province that characterizes the southern hemisphere, contrasting with the sparsely cratered plains generally confined to the northern hemisphere. Northwest of Argyre an outlier of sparsely cratered, ridged plains extends into the quadrangle from the Coprates region. Northeast of the basin are the cratered uplands, parts of which are presumed to represent remnants of the earliest martian crust (Wilhelms, 1974). South of the quadrangle the cratered plateau is replaced by the pitted, etched, layered, and mantled terrains that characterize the south polar region (Sharp, 1973a; Condit and Soderblom, 1978). Constructional volcanic landforms were not recognized within the map area.