Publication Date:
2017-04-28
Description:
Diagenetic silica enrichment in fracture-associated halos that cross-cut lacustrine and unconformably overlying aeolian sedimentary bedrock are observed on the lower north slope of Aeolis Mons in Gale crater, Mars. The diagenetic silica enrichment is co-located with detrital silica enrichment observed in the lacustrine bedrock, yet extends into a considerably younger, unconformably draping aeolian sandstone, implying that diagenetic silica enrichment post-dates the detrital silica enrichment. A causal connection between the detrital and diagenetic silica enrichment implies that water was present in the subsurface of Gale crater long after deposition of the lacustrine sediments, and that it mobilized detrital amorphous silica and precipitated it along fractures in the overlying bedrock. Although absolute timing is uncertain, the observed diagenesis likely represents some of the most recent groundwater activity in Gale crater, and suggests that the timescale of potential habitability extended considerably beyond the time that the lacustrine sediments of Aeolis Mons were deposited.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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