A volcanic origin for the outflow channels of Mars: Key evidence and major implications

Evidence for Middle Amazonian catastrophic flooding and glaciation on Mars

“…Individual landforms might also be explained by other flow processes such as with CO 2 (Hoffman, 2000) or lava as medium (Hopper and Leverington, 2014;Leverington, 2011). Nevertheless, the entire suite of observed landforms and their analogous relationship to those formed by cataclysmic flooding, provide a powerful indication that this was the formative process (Baker, 1982(Baker, , 2012.…”

“…1) have been the subject of much scientific inquiry since the 1970s (Baker and Milton, 1974;Carr, 1979) and they are thought to have been excavated on the planet's surface by catastrophic floods (Baker, 1982(Baker, , 2009a(Baker, , 2009b, glaciers (Lucchitta, 1982(Lucchitta, , 2001, CO 2 -charged debris flows (Hoffman, 2000), H 2 Ocharged debris flows (Nummedal and Prior, 1981), and/or lava flows (Hopper and Leverington, 2014;Leverington, 2011;Schonfeld, 1976). Importantly, the channels appear to mostly be $3 byr old (Rotto and Tanaka, 1995).…”

The physics of Martian weather and climate: a review

“…These features include widespread networks of sinuous valleys in the southern highlands of Mars, widespread plains in the tropics and northern sub-tropics that appear to be populated by erosion features consistent with massive flooding events, streamlined 'teardrop-shaped' islands, broad channels and chaotic terrains that appear to have been formed by catastrophic melting of ground ice, and even 'fossil coastlines', along with the suggested presence of a large-scale ocean covering much of the northern plains to a depth of up to 500 m (Baker et al 1991, Parker et al 1993, Head et al 1999. Although suggestions of other materials (such as liquid CO 2 (Hoffman 2000), wind erosion (Leovy 1999) or lava flows (Leverington 2011)) have been made in the past, the ubiquity of such features and their detailed morphology seem to demand an interpretation in terms of a fluid with a very low viscosity (ruling out most lavas) that must almost certainly involve large amounts of water in liquid form. Even in regions devoid of such massive flood features, mineral deposits have been observed, both from orbit and (recently) from surface rover investigation (Squyres et al 2008), consistent with sustained lakes of liquid water or brines.…”

Planetary geomorphology: Some historical/analytical perspectives

“…It would have to explain whole assemblages of landforms displaying temporal and spatial relationships (as revealed by geological mapping) that can clearly develop from a nexus of interrelated and connected chains of aqueous causation that are generally well understood from extensive study of their approximate equivalents on Earth. To have a complete mimicking of aqueous phenomena by carbon dioxide processes, by molten rock (e.g., Leverington, 2011), or by some other non-aqueous media would be a rather amazing discovery, with implications far beyond the study of Mars. The lack of detailed confirmation in the holistic sense noted above, however, makes these non-aqueous hypotheses for Mars geomorphology seem highly unlikely from the geological point of view.…”