Episodic ponding and outburst flooding associated with chaotic terrains in Valles Marineris

摘要: The Valles Marineris canyons are among the deepest of topographic depressions on Mars. As such, they may be expected to have served as sinks for a variety mobile materials, including water, regardless their particular formation history. interpretation ILD is not critical putative lake considered here. Considerably more important chaotic terrains, which constitute primary source water certain ancient lakes in, and near, Marineris. Chaotic terrains large regions fractured subsided materials found, in several cases, at termini canyons. Some that topographically connected suggest groundwater discharge these flooded both outflow channels. Such floods undoubtedly led ponding, either locally or points along drainage path. Coincidence MOLA-derived basin overflow point with channel erosion strongly supports ponding hypothesis. Although most likely ponded was terrain Capri Eos Chasmata, large-scale fractures bounding canyons, an alternative supply from northern plains ocean, has shoreline similar elevation paleolake, possible. Direct production by remains difficult explain, buffering effect provided surface circumvent this problem.