Uplifted Blocks of Light-Toned Layered Deposits in Mars

Uplifted Blocks of Light-Toned Layered Deposits in Mars. credit: NASA/JPL-Caltech/Univ. of Arizona

Aram Chaos lies within a 280 kilometre-diameter ancient impact crater in the Southern Highlands of Mars. Uplifted blocks of light-toned layers, composed largely of the iron-oxide hematite and water-altered silicates, indicate that this crater once held a lake. 

Scientists suggest that these enormous flood channels were carved quickly within just weeks or months by catastrophic outflows of groundwater over 2.5 billion years ago from beneath Aram Chaos and nearby regions. Today dark (basaltic) dunes fill most of the low regions and the etched areas of the uplifted blocks obscure much of the original crater floor. 

Map Projected Credit: HiRISE, NASA, JPL, University of Arizona

Aram Chaos is located near the headwaters of Ares Vallis, a large outflow channel system that extends about 1700 kilometers towards the northwest across the ancient cratered highlands before emptying into the Northern Lowlands at Chryse Planitia near the Mars Pathfinder landing site. 

Credit: HiRISE, NASA, JPL, University of Arizona, Wikipedia