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Contemporaneous deposition of phyllosilicates and sulfates: Using Australian acidic saline lake deposits to describe geochemical variability on Mars

Geophysical Research Letters

By:
, , , , , , , , , and
DOI: 10.1029/2009GL040069

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Abstract

Studies of the origin of the Martian sulfate and phyllosilicate deposits have led to the hypothesis that there was a marked, global-scale change in the Mars environment from circum-neutral pH aqueous alteration in the Noachian to an acidic evaporitic system in the late Noachian to Hesperian. However, terrestrial studies suggest that two different geochemical systems need not be invoked to explain such geochemical variation.Western Australian acidic playa lakes have large pH differences separated vertically and laterally by only a few tens of meters, demonstrating how highly variable chemistries can coexist over short distances in natural environments. We suggest diverse and variable Martian aqueous environments where the coetaneous formation of phyllosilicates and sulfates at the Australian sites are analogs for regions where phyllosilicates and sulfates coexist on Mars. In these systems, Fe and alkali earth phyllosilicates represent deep facies associated with upwelling neutral to alkaline groundwater, whereas aluminous phyllosilicates and sulfates represent near-surface evaporitic facies formed from more acidic brines. Copyright 2009 by the American Geophysical Union.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Contemporaneous deposition of phyllosilicates and sulfates: Using Australian acidic saline lake deposits to describe geochemical variability on Mars
Series title:
Geophysical Research Letters
DOI:
10.1029/2009GL040069
Volume
36
Issue:
19
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geophysical Research Letters