Degradation of Victoria crater, Mars

Journal of Geophysical Research E: Planets
By: , and 

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Abstract

The ∼750 m diameter and ∼75 m deep Victoria crater in Meridiani Planum, Mars, is a degraded primary impact structure retaining a ∼5 m raised rim consisting of 1–2 m of uplifted rocks overlain by ∼3 m of ejecta at the rim crest. The rim is 120–220 m wide and is surrounded by a dark annulus reaching an average of 590 m beyond the raised rim. Comparison between observed morphology and that expected for pristine craters 500–750 m across indicates that the original, pristine crater was close to 600 m in diameter. Hence, the crater has been erosionally widened by ∼150 m and infilled by ∼50 m of sediments. Eolian processes are responsible for most crater modification, but lesser mass wasting or gully activity contributions cannot be ruled out. Erosion by prevailing winds is most significant along the exposed rim and upper walls and accounts for ∼50 m widening across a WNW–ESE diameter. The volume of material eroded from the crater walls and rim is ∼20% less than the volume of sediments partially filling the crater, indicating eolian infilling from sources outside the crater over time. The annulus formed when ∼1 m deflation of the ejecta created a lag of more resistant hematite spherules that trapped <10–20 cm of darker, regional basaltic sands. Greater relief along the rim enabled meters of erosion. Comparison between Victoria and regional craters leads to definition of a crater degradation sequence dominated by eolian erosion and infilling over time.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Degradation of Victoria crater, Mars
Series title Journal of Geophysical Research E: Planets
DOI 10.1029/2008JE003155
Volume 113
Issue E11
Year Published 2008
Language English
Publisher American Geophysical Union
Publisher location Washington, D.C.
Contributing office(s) Astrogeology Science Center
Description 16 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Geophysical Research E: Planets
Other Geospatial Mars; Victoria crater