Aqueous alteration of the Nakhla meteorite

Details Aqueous alteration of the Nakhla meteorite Aqueous alteration of the Nakhla meteorite

Jun 1991

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1991metic..26..135g&link_type=abstract

Meteoritics (ISSN 0026-1114), vol. 26, June 1991, p. 135-143. NASA-supported research.

Computer Science

125

Geochemistry, Meteoritic Composition, Meteoritic Microstructures, Water, Abundance, Calcite, Mars (Planet), Metal Oxides, Olivine, Rusting

Scientific paper

Interior samples of three different Nakhla specimens contain an iron-rich silicate 'rust' (which includes a tentatively identified smectite), Ca-carbonate (probably calcite), Ca-sulfate (possibly gypsum or bassanite), Mg-sulfate (possibly epsomite or kieserite), and NaCl (halite); the total abundance of these phases is estimated as less than 0.01 weight percent of the bulk meteorite. Rust veins are truncated and decrepitated by fusion crust and are preserved as faulted segments in partially healed olivine crystals, indicating that the rust is preterrestrial in origin. Because Ca-carbonate and Ca-sulfate are intergrown with the rust, they are also indicated to be of preterrestrial origin. Similar textural evidence regarding origins of the NaCl and Mg-sulfate is lacking. Impure and poorly crystallized sulfates and halides on the fusion crust of the meteorite suggest leaching of interior (preterrestrial) salts from the interior after Makhla arrived on earth, but coincidental addition of these same salts by terrestrial contamination cannot be exluded. At least the clay-like silicate 'rust', Ca-carbonate, and Ca-sulfate were formed by precipitation from water-based solutions on the Nakhla parent planet, although temperature and pressure conditions of aqueous precipitation are unconstrained by currently available data. It is possible that aqueous alteration on the parent body was responsible for the previously observed disturbance of the Rb-Sr geochronometer in Nakhla at or near 1.3 Ga.

Affiliated with

Also associated with

No associations

Rating

Aqueous alteration of the Nakhla meteorite does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Aqueous alteration of the Nakhla meteorite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aqueous alteration of the Nakhla meteorite will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1285230