Acid-sulfate weathering of synthetic Martian basalt: The acid fog model revisited

Tosca, N. J. and McLennan, S. M. and Lindsley, D. H. and Schoonen, M. A. A. (2004) Acid-sulfate weathering of synthetic Martian basalt: The acid fog model revisited. Journal of Geophysical Research E: Planets, 109 (5). pp. 1991-2012. DOI 10.1029/2003JE002218

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Official URL: http://dx.doi.org/10.1029/2003JE002218

Abstract

The acid fog model has received considerable attention as a model of soil formation on Mars. Previous evaluations of this model have focused on experimental weathering of terrestrial basalt samples. However, these samples differ significantly from what now is thought to be typical of Martian basalt. The acid fog model is tested here using synthetic basaltic analogs derived from Mars Pathfinder soil and rock compositions. Reaction of synthetic basalt with various acidic solutions and subsequent evaporation has led to the formation of several putative secondary mineral phases. Many of these phases were not produced in prior experimental studies aimed at aqueous interactions on Mars. Of these alteration phases, Mg, Fe, Ca, and Al sulfates were identified. In addition, secondary ferric oxide phases formed via rapid Fe oxidation under relatively high pH levels buffered by basalt dissolution. Amorphous silica is a ubiquitous product in these experiments and has formed by precipitation from solution and by the dissolution of minerals and glasses leaving behind leached surface layers composed of residual silica. The secondary products formed in these experiments demonstrate the importance of primary mineralogy when testing models of aqueous interactions on Mars. New constraints are placed on both the reactivity of primary basalt and the secondary mineralogy present at the Martian surface. Copyright 2004 by the American Geophysical Union.

Item Type: Article
Additional Information: Copyright 2004 by the American Geophysical Union
Subjects: 01 - Climate Change and Earth-Ocean Atmosphere Systems
Divisions: 01 - Climate Change and Earth-Ocean Atmosphere Systems
08 - Green Open Access
Journal or Publication Title: Journal of Geophysical Research E: Planets
Volume: 109
Page Range: pp. 1991-2012
Identification Number: 10.1029/2003JE002218
Depositing User: Sarah Humbert
Date Deposited: 17 Dec 2009 12:02
Last Modified: 10 Jul 2014 11:31
URI: http://eprints.esc.cam.ac.uk/id/eprint/1253

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