Evidence of phyllosilicates in Wooly Patch, an altered rock encountered at West Spur, Columbia Hills, by the Spirit rover in Gusev crater, Mars

Journal of Geophysical Research E: Planets
By: , and 

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Abstract

On its traverse to Columbia Hills, the Mars Exploration Rover Spirit investigated an outcrop designated “Wooly Patch” that exhibited morphological, mineralogical, and geochemical characteristics at the extreme ends of ranges observed among rocks studied at West Spur, a westward projecting salient near the foot of the Columbia Hills, Gusev crater. The major‐element composition and Fe‐mineralogy, as determined by the Alpha‐Particle X‐ray Spectrometer and Mössbauer Spectrometer, are inconsistent with any reasonable assemblage of basaltic minerals in that there is an excess of Si and Al. The combined data are best explained by the presence of 14–17% phyllosilicate minerals. Phyllosilicates that account for the composition and cation ratios include members of the kaolinite, serpentine, chlorite, and septechlorite groups. The potential existence of kaolinite‐type Al‐rich phyllosilicates within the Wooly Patch outcrop suggests a mildly acidic environment (pH 4–6) in the past and an open hydrologic system with good drainage conditions in the environment where these rocks were altered.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Evidence of phyllosilicates in Wooly Patch, an altered rock encountered at West Spur, Columbia Hills, by the Spirit rover in Gusev crater, Mars
Series title Journal of Geophysical Research E: Planets
DOI 10.1029/2005JE002516
Volume 111
Issue E2
Year Published 2006
Language English
Publisher American Geophysical Union
Publisher location Washington, D.C.
Contributing office(s) Astrogeology Science Center
Description 22 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Geophysical Research E: Planets
Other Geospatial Columbia Hills; Gusev Crater; Mars; West Spur; Wooly Patch