TY - JOUR
T1 - Chemically striking regions on Mars and Stealth revisited
AU - Karunatillake, Suniti
AU - Wray, James J.
AU - Squyres, Steven W.
AU - Taylor, G. Jeffrey
AU - Gasnault, Olivier
AU - McLennan, Scott M.
AU - Boynton, William
AU - Maarry, M. R.El
AU - Dohm, James M.
PY - 2009/12
Y1 - 2009/12
N2 - The Mars Odyssey Gamma Ray Spectrometer Suite has yielded global chemical information for Mars. In this work, we establish regions of unusual chemical composition relative to average Mars primarily on the basis of Ca, Cl, Fe, H, K, Si, and Th. Using data from Mars Odyssey; the Mars Exploration Rovers; the Mars Reconnaissance Orbiter Imaging; and 3.5 cm and 1.35 cm radar observations from Earth, we examine a chemically striking ≈2.E6 km2 region and find it to overlap significantly with a radar Stealth region on Mars. It is remarkably enriched in Cl and depleted in Fe and Si (along with minor variations in H, K, and Th) relative to average Mars. Surface dust observed at the two rover sites mixed with and indurated by Ca/Mg-bearing sulfate salts would be a reasonable chemical and physical analog to meter-scale depths. We describe potential scenarios that may have contributed to the unique properties of this region. The bulk dust component may be an air fall deposit of compositionally uniform dust as observed in situ. Hydrothermal acid fog reactions on the flanks of nearby volcanoes may have generated sulfates with subsequent deflation and transport. Alternatively, sulfates may have been produced by low-temperature, regional-scale activity of ground ice-driven brine and/or regional-scale deposition of acidified H2O snowfall.
AB - The Mars Odyssey Gamma Ray Spectrometer Suite has yielded global chemical information for Mars. In this work, we establish regions of unusual chemical composition relative to average Mars primarily on the basis of Ca, Cl, Fe, H, K, Si, and Th. Using data from Mars Odyssey; the Mars Exploration Rovers; the Mars Reconnaissance Orbiter Imaging; and 3.5 cm and 1.35 cm radar observations from Earth, we examine a chemically striking ≈2.E6 km2 region and find it to overlap significantly with a radar Stealth region on Mars. It is remarkably enriched in Cl and depleted in Fe and Si (along with minor variations in H, K, and Th) relative to average Mars. Surface dust observed at the two rover sites mixed with and indurated by Ca/Mg-bearing sulfate salts would be a reasonable chemical and physical analog to meter-scale depths. We describe potential scenarios that may have contributed to the unique properties of this region. The bulk dust component may be an air fall deposit of compositionally uniform dust as observed in situ. Hydrothermal acid fog reactions on the flanks of nearby volcanoes may have generated sulfates with subsequent deflation and transport. Alternatively, sulfates may have been produced by low-temperature, regional-scale activity of ground ice-driven brine and/or regional-scale deposition of acidified H2O snowfall.
UR - http://www.scopus.com/inward/record.url?scp=76849084887&partnerID=8YFLogxK
U2 - 10.1029/2008JE003303
DO - 10.1029/2008JE003303
M3 - Article
AN - SCOPUS:76849084887
SN - 2169-9097
VL - 114
JO - Journal of Geophysical Research: Planets
JF - Journal of Geophysical Research: Planets
IS - 12
M1 - E12001
ER -