DOI: 10.1002/2017JE005270
Scopus记录号: 2-s2.0-85042075142
论文题名: Wind-Eroded Crater Floors and Intercrater Plains, Terra Sabaea, Mars
作者: Irwin R.P. ; III ; Wray J.J. ; Mest S.C. ; Maxwell T.A.
刊名: Journal of Geophysical Research: Planets
ISSN: 21699097
出版年: 2018
卷: 123, 期: 2 起始页码: 445
结束页码: 467
语种: 英语
英文关键词: crater floors
; intercrater plains
; Mars
; spectroscopy
; stratigraphy
Scopus关键词: cementation
; crater
; Mars
; paleochannel
; spectroscopy
; stratification
; stratigraphy
; wind erosion
英文摘要: Ancient impact craters with wind-eroded layering on their floors provide a record of resurfacing materials and processes on early Mars. In a 54 km Noachian crater in Terra Sabaea (20.2°S, 42.6°E), eolian deflation of a friable, dark-toned layer up to tens of meters thick has exposed more resistant, underlying light-toned material. These layers differ significantly from strata of similar tone described in other regions of Mars. The light-toned material has no apparent internal stratification, and visible/near-infrared spectral analysis suggests that it is rich in feldspar. Its origin is ambiguous, as we cannot confidently reject igneous, pyroclastic, or clastic alternatives. The overlying dark-toned layer is probably a basaltic siltstone or sandstone that was emplaced mostly by wind, although its weak cementation and inverted fluvial paleochannels indicate some modification by water. Negative-relief channels are not found on the crater floor, and fluvial erosion is otherwise weakly expressed in the study area. Small impacts onto this crater's floor have exposed deeper friable materials that appear to contain goethite. Bedrock outcrops on the crater walls are phyllosilicate bearing. The intercrater plains contain remnants of a post-Noachian thin, widespread, likely eolian mantle with an indurated surface. Plains near Hellas-concentric escarpments to the north are more consistent with volcanic resurfacing. A 48 km crater nearby contains similar dark-over-light outcrops but no paleochannels. Our findings indicate that dark-over-light stratigraphy has diverse origins across Mars and that some dark-toned plains with mafic mineralogy are not of igneous origin. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114511
Appears in Collections: 气候减缓与适应
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作者单位: Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC, United States; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States; Planetary Science Institute, Tucson, AZ, United States
Recommended Citation:
Irwin R.P.,III,Wray J.J.,et al. Wind-Eroded Crater Floors and Intercrater Plains, Terra Sabaea, Mars[J]. Journal of Geophysical Research: Planets,2018-01-01,123(2)