Schwenzer, S. P.; Abramov, O.; Allan, C. C.; Clifford, S. M.; Cockell, C. S.; Filiberto, J. ; Kring, D. A.; Lasue, J.; McGovern, P. J.; Newsom, H. E.; Treiman, A. H.; Vaniman, D. T. and Wiens, R. C.
|DOI (Digital Object Identifier) Link:||http://doi.org/10.1016/j.epsl.2012.04.031|
|Google Scholar:||Look up in Google Scholar|
Geologic evidence suggests that the Martian surface and atmospheric conditions underwent major changes in the late Noachian, with a decline in observable water-related surface features, suggestive of a transition to a dryer and colder climate. Based on that assumption, we have modeled the consequences of impacts into a ~2–6 km-thick cryosphere. We calculate that medium-sized( few 10s of km diameter impact craters can physically and/or thermally penetrate through this cryosphere, creating liquid water through the melting of subsurface ice in an otherwise dry and frozen environment. The interaction of liquid water with the target rock produces alteration phases that thermochemical modeling predicts will include hydrous silicates (e.g.,nontronite, chlorite, serpentine). Thus, even small impact craters are environments that combine liquid water and the presence of alteration minerals that make them potential sites for life to proliferate. Expanding on the well-known effects of large impact craters on target sites, we conclude that craters as small as ~5–20 km (depending on latitude)excavate large volumes of material from the subsurface while delivering sufficient heat to create liquid water(through the melting of ground ice) and drive hydrothermal activity. This connection between the surface and subsurface made by the formation of these small, and thus more frequent, impact craters may also represent the most favorable sites to test the hypothesis of life on early Mars.
|Item Type:||Journal Article|
|Copyright Holders:||2012 Elsevier B.V.|
|Project Funding Details:||
|Keywords:||Early Mars; cryosphere; impact crater; impact-generated hydrothermal; astrobiology; search for extraterrestrial life; Mars surface; impact processes|
|Academic Unit/Department:||Faculty of Science, Technology, Engineering and Mathematics (STEM) > Environment, Earth and Ecosystem Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
|Interdisciplinary Research Centre:||Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)|
|Depositing User:||Susanne Schwenzer|
|Date Deposited:||18 Jun 2012 14:25|
|Last Modified:||02 Aug 2016 14:18|
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