The nature of Martian fluids based on mobile element studies in salt-assemblages from Martian meteorites
- UofC
The S, Cl, and Br abundances determined in salt assemblages in Nakhla and Lafayette olivine fracture fillings and in gas-rich impact-melt (GRIM) glasses from Shergotty and EET79001 Lithologies A & B using EMPA/EDS/APS X-ray Microprobe techniques are compared with the S and Cl abundances determined by Gooding and coworkers in similar samples using quadrupole mass-spectrometric techniques. All the analytical methods yield relatively high Cl and low SO{sub 3} abundances in Nakhla indicating a SO{sub 3}/Cl ratio of {approx}0.2. The same ratio in Lafayette secondary salts seems to be {approx}2. In the case of GRIM glasses from Shergotty and EET79001 Lith A & Lith B, the SO{sub 3} abundance is found to be high whereas the Cl abundance is low yielding a SO{sub 3}/Cl ratio of {approx}5--300 (large errors are associated with these ratios because of low Cl signals). The salts found in Nakhla fracturefillings are inferred to have formed from Cl-rich fluids (high pH) near nakhlite source region on Mars, whereas the secondary minerals found in shergottite GRIM glasses seem to be associated with SO{sub 3}-rich fluids (low pH) near shergottite source region on Mars. The Cl-rich fluids seem to have infiltrated into the nakhlite source region {approx}600 Ma ago, whereas the SO{sub 3}-rich fluids likely percolated into the shergottite source region at {approx}180 Ma (or less) suggesting the possible existence of two types of fluid sources on Mars.
- Research Organization:
- Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1006637
- Journal Information:
- J. Geophys. Res., Journal Name: J. Geophys. Res. Journal Issue: 06, 2008 Vol. 113; ISSN JGREA2; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- ENGLISH
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