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- Title
Evidence for remnants of ancient ice-rich deposits: Mangala Valles outflow channel, Mars.
- Authors
Levy, Joseph S.; Head, James W.
- Abstract
High-resolution spacecraft data reveal the presence of a distinctive unit on the upper reaches of the floor of Mangala Valles, an ancient outflow channel on Mars. In contrast to abundant evidence for scour, intense erosion, and hydrodynamic shaping typical of the floors and margins of Mangala and other outflow channels, this unit is smooth-surfaced, has cuspate margins, is superposed on the scoured valley floor, and is extensively pitted. We interpret this unit to be the sublimation lag deposit derived from an ice thermal boundary layer on the aqueous flood that formed the outflow channel system, and the remnant of floodwaters trapped in channel lows. This interpretation further supports the likelihood that climate conditions at the time of emplacement were similar to the hyper-arid cold desert conditions of today. Frozen floodwaters from the ancient martian subsurface could still be preserved in these deposits, representing attractive and accessible exobiological exploration objectives.
- Subjects
MARTIAN geology; THERMAL boundary layer; ASTROGEOLOGY; PLANETARY geology; BOUNDARY layer (Aerodynamics); MARS (Planet); HEAT transfer; MARTIAN meteorology; FLOODS
- Publication
Terra Nova, 2005, Vol 17, Issue 6, p503
- ISSN
0954-4879
- Publication type
Article
- DOI
10.1111/j.1365-3121.2005.00642.x