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Mineralogy and fluvial history of the watersheds of Gale, Knobel, and Sharp craters: A regional context for the Mars Science Laboratory Curiosity's exploration
Author(s) -
Ehlmann Bethany L.,
Buz Jennifer
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl062553
Subject(s) - impact crater , hesperian , noachian , bedrock , geology , fluvial , mars exploration program , context (archaeology) , amazonian , geochemistry , geomorphology , crater lake , lava , volcano , earth science , astrobiology , martian , paleontology , amazon rainforest , ecology , physics , structural basin , biology
A 500 km long network of valleys extends from Herschel crater to Gale, Knobel, and Sharp craters. The mineralogy and timing of fluvial activity in these watersheds provide a regional framework for deciphering the origin of sediments of Gale crater's Mount Sharp, an exploration target for the Curiosity rover. Olivine‐bearing bedrock is exposed throughout the region, and its erosion contributed to widespread olivine‐bearing sand dunes. Fe/Mg phyllosilicates are found in both bedrock and sediments, implying that materials deposited in Gale crater may have inherited clay minerals, transported from the watershed. While some topographic lows of the Sharp‐Knobel watershed host chloride salts, the only salts detected in the Gale watershed are sulfates within Mount Sharp, implying regional or temporal differences in water chemistry. Crater counts indicate progressively more spatially localized aqueous activity: large‐scale valley network activity ceased by the early Hesperian, though later Hesperian/Amazonian fluvial activity continued near Gale and Sharp craters.