Conference proceeding
ChemCam first discovery of high silica sediments in Gale Crater
American Geophysical Union Fall Meeting, Vol.2015
American Geophysical Union 2015 fall meeting
12/2015
Abstract
On sol 991, The Curiosity rover ascended a steep slope to Marias Pass in Gale Crater. Close to the top, ChemCam analyzed the rock target Elk from an apparent bright unit. Utilizing the new elemental calibration implemented for ChemCam in the summer of 2015, four of five points on Elk were measured to contain 76-82 wt% SiO (sub 2) and >3 wt% TiO (sub 2) , whereas the last point showed elevated CaSO (sub 4) . The Elk target is identified to be part of the Murray formation, and hence related to the Pahrump area mudstones that were subjected to intensive studies by the Curiosity rover team over the sols 758-948. While the Murray formation west of Elk did show elevated SiO (sub 2) ( approximately 65 wt%) compared to the Pahrump area, no targets with similarly high SiO (sub 2) wt% as Elk were observed, thus prompting--together with detection of anomalously high DAN H signals in the same area--the Curiosity rover to return to the Elk target area for additional analyses. This return led to numerous additional high Si observations (targets Pistol, Mary, Shepard, Dublin Gulch and Frog) that all corroborated the initial high Si observation at Elk. Additionally, the Alpha Particle X-ray Spectrometer (APXS) analyzed the target Lamoose and found SiO (sub 2) content in excess of 72 wt% and moderately elevated TiO (sub 2) . Considering the difference in footprint (1.7 cm for APXS vs approximately 400mu m for ChemCam) and the fact that the target couldn't be brushed, this is considered a good corroboration of the very high Si observed with ChemCam. These targets suggest that the Elk-area targets represent an end-member of the Murray formation, but there are multiple working hypotheses for the origin of the high SiO (sub 2) and TiO (sub 2) in these: 1. primary precipitates from the water column of a lake, 2. a post-depositional leaching/weathering front and 3. a hydrothermal silica precipitate.
Details
- Title: Subtitle
- ChemCam first discovery of high silica sediments in Gale Crater
- Creators
- Jens Frydenvang - Los Alamos National LaboratoryPatrick J. GasdaRoger C. WiensHorton E. NewsomJohn BridgesOlivier GasnaultSylvestre MauriceOlivier ForniNicolas MangoldAgnes CousinValerie PayreRyan B. AndersonIgor G. MitrofanovInsoo JunMelissa S. RiceRalph MillikenPeter EdwardsDavid T. VanimanRichard V. MorrisDavid F. BlakeRalf GellertLucy M. ThompsonBenton C. ClarkJoel HurowitzDawn Y. SumnerBethany L. EhlmannAbigail FraemanKjartan M. KinchMorten B. MadsenFred CalefJohn P. GrotzingerAshwin R. VasavadaMars Science Laboratory (MSL) Science Team
- Resource Type
- Conference proceeding
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2015
- Conference
- American Geophysical Union 2015 fall meeting
- Publisher
- American Geophysical Union
- Alternative title
- AGU 2015 fall meeting
- Language
- English
- Date published
- 12/2015
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984318344502771
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