Publication Date:
2004-08-07
Description:
The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain 〈/=25% megacrysts. Chemical analyses of rocks by the Alpha Particle X-ray Spectrometer are consistent with picritic basalts, containing normative olivine, pyroxenes, plagioclase, and accessory FeTi oxides. Mossbauer, Pancam, and Mini-TES spectra confirm the presence of olivine, magnetite, and probably pyroxene. These basalts extend the known range of rock compositions composing the martian crust.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McSween, H Y -- Arvidson, R E -- Bell, J F 3rd -- Blaney, D -- Cabrol, N A -- Christensen, P R -- Clark, B C -- Crisp, J A -- Crumpler, L S -- Des Marais, D J -- Farmer, J D -- Gellert, R -- Ghosh, A -- Gorevan, S -- Graff, T -- Grant, J -- Haskin, L A -- Herkenhoff, K E -- Johnson, J R -- Jolliff, B L -- Klingelhoefer, G -- Knudson, A T -- McLennan, S -- Milam, K A -- Moersch, J E -- Morris, R V -- Rieder, R -- Ruff, S W -- De Souza, P A Jr -- Squyres, S W -- Wanke, H -- Wang, A -- Wyatt, M B -- Yen, A -- Zipfel, J -- New York, N.Y. -- Science. 2004 Aug 6;305(5685):842-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996-1410, USA. mcsween@utk.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15297668" target="_blank"〉PubMed〈/a〉
Keywords:
Extraterrestrial Environment
;
Geologic Sediments
;
Iron Compounds
;
Magnesium Compounds
;
*Mars
;
*Minerals
;
Oxides
;
*Silicates
;
Spectroscopy, Mossbauer
;
Spectrum Analysis
;
Water
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
