Formation of Ares Vallis (Mars) by effusions of low-viscosity lava within multiple regions of chaotic terrain

摘要: Abstract Ares Vallis is one of the largest outflow channels on Mars, extending northward >1500 km from highlands Margaritifer Terra into Chryse impact basin. This system developed primarily during Hesperian and Amazonian as a result voluminous effusions subsurface that took place within Iani Chaos, Aram Hydaspis Chaos. Though widely interpreted product catastrophic outbursts aquifers, its basic attributes do not appear to support aqueous origins any kind: aquifer outburst mechanisms lack meaningful solar analogs, clear examples fluvial or diluvial sedimentary deposits are apparently absent at Vallis, there no mineralogical evidence along component terminal basins for extensive alteration deposition thick evaporite units. Instead, case hundreds ancient inner system, nature aligned with dry volcanic origins. Such broadly consistent system's relatively pristine mineralogy, widespread mantling by lava flows, apparent presence mare-style flood lavas basins. With assumed viscosities 1 Pa s temperatures 1350 °C, discharge rates ~97 × 106 m3/s estimated 100-m-deep flows channel reaches widths 25 km slopes only 0.2°. Mechanical thermal incision respectively be ~12.2 m/day 2.3 m/day these slopes. Formation main associated regions chaos likely have required minimum effused volume ~1.8 × 106 km3, still greater volumes would been necessary form including those located south