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MN Carbonates in the Martian Meteorite Nakhla: Possible Evidence of Brine EvaporationThe importance of secondary phases in martian meteorites lies in their potential to provide clues about the martian environments responsible for their formation. During this study, we analyzed a number of carbonate-bearing fracture surfaces from the Nakhla meteorite. Here we describe the physical and chemical properties of several manganese-calcium-rich siderites. Additionally, we describe a potential model for the formation and alteration of these carbonates, and we suggest constraints on the conditions responsible for their precipitation. Nakhla is an olivine-bearing clinopyroxenite with minor amounts of feldspar, FeS, and Fe oxides. Secondary mineral assemblages include vein filling clay with embedded iron oxides, a calcium sulfate, amorphous silica, chlorapatite, halite and carbonates. Bridges and Grady suggested that the carbonates in Nakhla formed from brine evaporation. Isotope studies of the Mn rich siderite are also consistent with formation from hydrothermal fluids with an upper T constraint of ~170 C.
Document ID
Acquisition Source
Document Type
Conference Paper
Bailey, J. V.
(Arizona Univ. Tucson, AZ, United States)
McKay, D. S.
(NASA Johnson Space Center Houston, TX, United States)
Wentworth, S. J.
(Lockheed Martin Corp. Houston, TX, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Publication Information
Publication: Lunar and Planetary Science XXXIV
Subject Category
Lunar And Planetary Science And Exploration
Report/Patent Number
Distribution Limits
Public Use Permitted.
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