ChemCam results from the Shaler outcrop in Gale crater, Mars
International audience The ChemCam campaign at the fluvial sedimentary outcrop ‘‘Shaler’’ resulted in observations of 28non-soil targets, 26 of which included active laser induced breakdown spectroscopy (LIBS), and all ofwhich included Remote Micro-Imager (RMI) images. The Shaler outcrop can be divi...
Published in: | Icarus |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Other Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2015
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-01122787 https://doi.org/10.1016/j.icarus.2014.07.025 |
Summary: | International audience The ChemCam campaign at the fluvial sedimentary outcrop ‘‘Shaler’’ resulted in observations of 28non-soil targets, 26 of which included active laser induced breakdown spectroscopy (LIBS), and all ofwhich included Remote Micro-Imager (RMI) images. The Shaler outcrop can be divided into seven faciesbased on grain size, texture, color, resistance to erosion, and sedimentary structures. The ChemCamobservations cover Facies 3 through 7. For all targets, the majority of the grains were below the limitof the RMI resolution, but many targets had a portion of resolvable grains coarser than 0.5 mm. The Shalerfacies show significant scatter in LIBS spectra and compositions from point to point, but several keycompositional trends are apparent, most notably in the average K2O content of the observed facies. Facies3 is lower in K2O than the other facies and is similar in composition to the ‘‘snake,’’ a clastic dike thatoccurs lower in the Yellowknife Bay stratigraphic section. Facies 7 is enriched in K2O relative to the otherfacies and shows some compositional and textural similarities to float rocks near Yellowknife Bay. Theremaining 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 FeOT. Several analysis points within Shaler suggestthe presence of feldspars, though these points have excess FeOT which suggests the presence of Feoxide cement or inclusions. The majority of LIBS analyses have compositions which indicate that theyhttp://dx.doi.org/10.1016/j.icarus.2014.07.0250019-1035/Published by Elsevier Inc.⇑ Corresponding author.E-mail addresses: rbanderson@usgs.gov (R. Anderson), jcb36@leicester.ac.uk (J.C. Bridges), amywill@ucdavis.edu (A. Williams), ledgar1@asu.edu (L. Edgar), aollila@unm.edu (A. Ollila), josh505@unm.edu (J. Williams), marion.nach@gmail.com (M. Nachon), nicolas.mangold@univ-nantes.fr (N. Mangold), Martin.Fisk@oregonstate.edu (M. Fisk),jschiebe@indiana.edu (J. Schieber), ... |
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