ChemCam results from the Shaler outcrop in Gale crater, Mars Public Deposited

http://ir.library.oregonstate.edu/concern/articles/b5644t197

To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at:  http://www.journals.elsevier.com/icarus.

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • The ChemCam campaign at the fluvial sedimentary outcrop ‘‘Shaler’’ resulted in observations of 28 non-soil targets, 26 of which included active laser induced breakdown spectroscopy (LIBS), and all of which included Remote Micro-Imager (RMI) images. The Shaler outcrop can be divided into seven facies based on grain size, texture, color, resistance to erosion, and sedimentary structures. The ChemCam observations cover Facies 3 through 7. For all targets, the majority of the grains were below the limit of the RMI resolution, but many targets had a portion of resolvable grains coarser than ~0.5 mm. The Shaler facies show significant scatter in LIBS spectra and compositions from point to point, but several key compositional trends are apparent, most notably in the average K₂O content of the observed facies. Facies 3 is lower in K₂O than the other facies and is similar in composition to the ‘‘snake,’’ a clastic dike that occurs lower in the Yellowknife Bay stratigraphic section. Facies 7 is enriched in K₂O relative to the other facies and shows some compositional and textural similarities to float rocks near Yellowknife Bay. The remaining facies (4, 5, and 6) are similar in composition to the Sheepbed and Gillespie Lake members, although the Shaler facies have slightly elevated K₂O and FeO[subscript T]. Several analysis points within Shaler suggest the presence of feldspars, though these points have excess FeO[subscript T] which suggests the presence of Fe oxide cement or inclusions. The majority of LIBS analyses have compositions which indicate that they are mixtures of pyroxene and feldspar. The Shaler feldspathic compositions are more alkaline than typical feldspars from shergottites, suggesting an alkaline basaltic source region, particularly for the K₂O-enriched Facies 7. Apart from possible iron-oxide cement, there is little evidence for chemical alteration at Shaler, although calcium-sulfate veins comparable to those observed lower in the stratigraphic section are present. The differing compositions, and inferred provenances at Shaler, suggest compositionally heterogeneous terrain in the Gale crater rim and surroundings, and intermittent periods of deposition.
Resource Type
DOI
Date Available
Date Issued
Citation
  • Anderson, R., Bridges, J. C., Williams, A., Edgar, L., Ollila, A., Williams, J., ... & Vaniman, D. (2015). ChemCam results from the Shaler outcrop in Gale Crater, Mars. Icarus, 249, 2-21. doi:10.1016/j.icarus.2014.07.025
Series
Keyword
Rights Statement
Funding Statement (additional comments about funding)
Publisher
Peer Reviewed
Language
Replaces
Additional Information
  • description.provenance : Submitted by Erin Clark (erin.clark@oregonstate.edu) on 2015-03-10T22:46:43Z No. of bitstreams: 1 FiskMartinCEOASChemCamResultsShaler.pdf: 7476678 bytes, checksum: 4f3a35834ef5f6a57aa1f8980e339d48 (MD5)
  • description.provenance : Approved for entry into archive by Erin Clark(erin.clark@oregonstate.edu) on 2015-03-10T22:46:59Z (GMT) No. of bitstreams: 1 FiskMartinCEOASChemCamResultsShaler.pdf: 7476678 bytes, checksum: 4f3a35834ef5f6a57aa1f8980e339d48 (MD5)
  • description.provenance : Made available in DSpace on 2015-03-10T22:46:59Z (GMT). No. of bitstreams: 1 FiskMartinCEOASChemCamResultsShaler.pdf: 7476678 bytes, checksum: 4f3a35834ef5f6a57aa1f8980e339d48 (MD5) Previous issue date: 2015-03-15

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items