HR: 16:30h
AN: P34A-03 INVITED    [Abstracts]
TI: High-Resolution Imaging of Lava Flow Terrains on Mars by MRO HiRISE
AU: * Crumpler, L S
EM: larry.crumpler@state.nm.us
AF: New Mexico Museum of Natural History, 18091 Mountain Rd NW, Albuquerque, NM 87104, United States
AU: Keszthelyi, L P
EM: laz@usgs.gov
AF: U.S. Geological Survey, 2255 N. Gemini Drive, Flagstaff, AZ 86001, United States
AU: Jaeger, W L
EM: wjaeger@usgs.gov
AF: U.S. Geological Survey, 2255 N. Gemini Drive, Flagstaff, AZ 86001, United States
AU: McEwen, A S
EM: mcewen@pirl.lpl.arizona.edu
AF: University of Arizona, Lunar and Planetary Lab, Tucson, AZ 85721, United States
AU: TEAM, H
EM: hri@pirlserver.lpl.arizona.edu
AF: University of Arizona, Lunar and Planetary Lab, Tucson, AZ 85721, United States
AB: Lava flows account for a significant fraction of the surface of Mars and HiRISE has imaged a diverse selection of these areas at resolutions comparable to "air photos" on Earth. Although some lava are extensively impact "gardened" or mantled, many areas retain primary geomorphologic information at meter-scale. Primary characteristics similar to that of late Cenozoic lava flows in arid areas of Earth are visible in the HiRISE images of even some Hesperian lava plains. The extensive mantling by wind-blown deposits in some of the more youthful volcanic terrains (e.g., Tharsis) may, like terrestrial counterparts, be a result of the excessively rough surface trapping mobilized sand. Evidence for lava flow inflation, including lava-rise plateaus and pits and deformation both vertically and laterally of lava crusts, is documented in areas of flood lavas. Other lava flows are clearly fed from surface channels resulting in dispersive flow surface pattern. Lava flows with hummocky surface textures are comparable to terrestrial flows with auto-brecciated and disturbed surfaces, but the Martian flows are often much larger than typical terrestrial examples. Kilometer-scale areas of puzzle-work plates characterize some flood lava flows. The abundance of plate-like and rubbly deformation styles observed at many localities on Mars is consistent with examples of rubbly pahoehoe seen in situ by the Spirit rover. Rubbly pahoehoe may be a common primary surface texture for many areas of plains-like lava flow emplacement such as the Hesperian lava plains. Sinuous rill-like channels headed at distinct vents and collapse pits suggest significant lava erosion and correspondingly high effusion rates. While the Athabasca Valles channel bed forms appear to be associated with major aqueous outflows, the entire region is draped with lava.
DE: 6225 Mars
DE: 8425 Effusive volcanism
DE: 8429 Lava rheology and morphology
DE: 8450 Planetary volcanism (5480, 6063, 8148)
DE: 8486 Field relationships (1090, 3690)
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting