Observations at the Mars Pathfinder site: Do they provide "unequivocal" evidence of catastrophic flooding?

After Mars Pathfinder landed at the mouth of Ares Vallis, a large channel t hat drains into the Chryse Planitia basin, the mission reports unanimously supported the interpretation that the lander site is the locus of catastrop hic flooding by noting that all aspects of the scene are consistent with th is interpretation. However, alternatives cannot be ruled out by any site ob servations, as all aspects of the scene are equally consistent with other i nterpretations of origin, namely, ice and mass-flow processes subsequently modified by wind erosion. The authors discuss alternative explanations for the geologic history of the channel based on a regional view of the circum- Chryse channels from Viking images (our best broad-scale information to dat e) and the local view from the recent Pathfinder landing site. Mega-indicat ors of channel origin, the regional geomorphology, geology, and planetary c limatic conditions, taken together suggest some combination of flood, mass flow, glacial, and eolian processes. The macro-indicators of channel origin (sedimentologic) are also not indicative of one process of emplacement, ei ther as single criteria or taken cumulatively. Finally, the micro-indicator s of channel origin (geochemical and mineralogic composition) do not provid e very tight constraints on the deposits' possible origins other than that water was in some way involved.