Clay minerals
Aureum Chaos is a major canyon system and collapsed area. Large outflow channels on Mars are believed to be caused by catastrophic discharges of ground water. Many of the channels begin in chaotic terrain, where the ground has apparently collapsed. In the collapsed section, blocks of undisturbed material can be seen. The OMEGA experiment on Mars Express discovered clay minerals (phyllosilicates) in a variety places in Aureum Chaos. Clay minerals need water to form, so the area may once have contained large amounts of water. Scientists are interested in determining what parts of Mars contained water because evidence of past or present life may be found there. Aureum Chaos is one more piece of evidence that Mars once had great amounts of water.