Catastrophic outwash plains on Earth and Mars
- 出版日期：2008.
- 页数：1 online resource.
- 第一责任说明：Nicholas Hale Warner.
- 分类号：a281 ; a253.95
- ISBN：9780549862093(e-book) :
MARC全文
62h0061884 20140425143210.0 cr an |||||||| 140425s2008 a fsbm |000|0 eng | 3334204 9780549862093(e-book) : CNY416.00 UMI UMI NGL a281 ; a253.95 Warner, Nicholas Hale. Catastrophic outwash plains on Earth and Mars [electronic resource] : comparisons from Iceland and Chasma Boreale, Mars / Nicholas Hale Warner. 2008. 1 online resource. Source: Dissertation Abstracts International, Volume: 69-10, Section: B, page: 5992. ; Description based on online resource; title from title page (viewed Apr. 25th, 2014) Thesis (Ph.D.)--Arizona State University, 2008. Mid-latitude and polar canyons on Mars may represent catastrophic outflow channels generated by geothermal melting of the cryosphere. Possible terrestrial analogs to the Martian systems exist in Iceland where sub-glacial melting induced by volcanism results in catastrophic outflow and deposition of basaltic material onto sandur surfaces. An analysis of the geomorphology and sedimentology of Icelandic systems is used to make direct comparisons to the Martian systems. Furthermore, remote and laboratory identification of basaltic hydrothermal alteration minerals on Icelandic catastrophic outflow surfaces suggests potential for identification of similar materials in Martian outflow deposits. The sandur plains of southeastern Iceland are dominated by boulder to sand-sized clasts of basaltic lavas, palagonitized tuffs, and palagonitized breccias. Palagonite breccia and tuffs represent the dominant basaltic alteration material and comprise <1--20% of clasts exposed on the sandur surface. X-ray diffraction analyses of breccia clasts indicate authigenic mineral assemblages suggestive of sub-glacial hydrothermal alteration at temperatures of 100--120 degrees C. Visible-light and near-infrared lab spectroscopy of palagonite breccia clasts and sandur mixtures show water and OH absorptions at 1.4, 1.9, 2.20, 2.29, and 2.31 microns associated with clay minerals and zeolites. Visible-light/near-infrared remote sensing data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) reveal diagnostic clay absorptions between 2.20 and 2.30 microns in bedrock proximal localities on the sandur surfaces corresponding with the regions of highest palagonite abundance and coarsest grain size. A detailed morphologic analysis of the most commonly cited Martian analog to the Icelandic systems, Chasma Boreale, reveals a non-outflow origin and an overall geomorphology dissimilar to fluvial systems and the Icelandic sandur plains. Chasma Boreale, a 500-km-long, 60-km-wide, and 1 km deep north polar re-entrant contains steep (8--30 degrees) equator-facing scarps that show evidence for extensive long-term scarp retreat. This retreat mechanism is related to long-term scarp modification by solar ablation, mass wasting, and katabatic wind erosion. The development of unusually strong katabatic winds along previously existing polar scarps may be a mechanism for opening and lengthening of the chasma system and isolation of conical remnants of polar layered material. Geology Iceland. Mars (Planet) ; Mars (Planet) Surface. ; Geology. Electronic dissertations local. aInternet resource. Arizona State University. aCN b010001 http://pqdt.bjzhongke.com.cn/Detail.aspx?pid=4Oi2ueXXU3E%3d 010001 Bs3302 rCNY416.00 ; h1 bs1405