Opportunity, Geologic and Structural Context of Aqueous Alteration in Noachian Outcrops, Marathon Valley and Rim and Endeavour CraterIn its 12th year of exploration and 1600 sols since arrival at the rim of the 22 km-diameter Noachian Endeavour impact crater, Mars Exploration Rover Opportunity traversed from the summit of the western rim segment "Cape Tribulation" to "Marathon Valley", a shallow trough dissecting the rim and the site of strong orbital detection of smectites. In situ analysis of the exposures within Marathon Valley is establishing some of the geologic and geochemical controls on the aqueous alteration responsible for smectite detection known to occur in crater rims throughout Noachian terrains of Mars.
Crumpler, L. S. (New Mexico Museum of Natural History and Science Albuquerque, NM, United States)
Arvidson, R. E. (Washington Univ. Saint Louis, MO, United States)
Mittlefehldt, D. W. (NASA Johnson Space Center Houston, TX, United States)
Jolliff, B. L. (Washington Univ. Saint Louis, MO, United States)
Farrand, W. H. (Space Science Inst. Boulder, CO, United States)
Fox, V. (Washington Univ. Saint Louis, MO, United States)
Golombek, M. P. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)