Mineralogy, provenance, and diagenesis of a potassic basaltic sandstone on Mars: CheMin X-ray diffraction of the Windjana sample (Kimberley area, Gale Crater)
File(s)
Author(s)
Type
Journal Article
Abstract
The Windjana drill sample, a sandstone of the Dillinger member (Kimberley formation, Gale Crater, Mars), was analyzed by CheMin X-ray diffraction (XRD) in the MSL Curiosity rover. From Rietveld refinements of its XRD pattern, Windjana contains the following: sanidine (21% weight, ~Or95); augite (20%); magnetite (12%); pigeonite; olivine; plagioclase; amorphous and smectitic material (~25%); and percent levels of others including ilmenite, fluorapatite, and bassanite. From mass balance on the Alpha Proton X-ray Spectrometer (APXS) chemical analysis, the amorphous material is Fe rich with nearly no other cations—like ferrihydrite. The Windjana sample shows little alteration and was likely cemented by its magnetite and ferrihydrite. From ChemCam Laser-Induced Breakdown Spectrometer (LIBS) chemical analyses, Windjana is representative of the Dillinger and Mount Remarkable members of the Kimberley formation. LIBS data suggest that the Kimberley sediments include at least three chemical components. The most K-rich targets have 5.6% K2O, ~1.8 times that of Windjana, implying a sediment component with >40% sanidine, e.g., a trachyte. A second component is rich in mafic minerals, with little feldspar (like a shergottite). A third component is richer in plagioclase and in Na2O, and is likely to be basaltic. The K-rich sediment component is consistent with APXS and ChemCam observations of K-rich rocks elsewhere in Gale Crater. The source of this sediment component was likely volcanic. The presence of sediment from many igneous sources, in concert with Curiosity's identifications of other igneous materials (e.g., mugearite), implies that the northern rim of Gale Crater exposes a diverse igneous complex, at least as diverse as that found in similar-age terranes on Earth.
Date Issued
2016-01
Date Acceptance
2015-12-21
Citation
Journal of Geophysical Research: Planets, 2016, 121 (1), pp.75-106
ISSN
2169-9100
Publisher
American Geophysical Union (AGU)
Start Page
75
End Page
106
Journal / Book Title
Journal of Geophysical Research: Planets
Volume
121
Issue
1
Copyright Statement
© 2015 The Authors.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Grant Number
ST/J005169/1
ST/N000579/1
Subjects
Science & Technology
Physical Sciences
Geochemistry & Geophysics
Mars
CheMin
MSL
Windjana
sandstone
X-ray diffraction
NORTHWEST AFRICA 7034
A-TYPE GRANITES
ALKALINE MAGMATISM
CRYSTAL-STRUCTURE
STRUCTURAL STATE
MARTIAN MANTLE
MOSSBAUER-SPECTROSCOPY
SOUTHERN CALIFORNIA
CATION DISTRIBUTION
SEDIMENTARY-ROCKS
X‐ray diffraction
Publication Status
Published
Date Publish Online
2015-12-27