Apxs derived geochemistry of shallow water lens bodies within the Mirador formation, Gale Crater, Mars - evidence for intermittent wet periods and implications for the water record
Author(s)
Type
Journal Article
Abstract
The Mount Sharp group in Gale crater is typically interpreted to record a progressive change (with increasing elevation) from wetter fluvio-lacustrine environments to dry, eolian environments. This shift has been linked to orbital evidence for a global change in environmental and depositional conditions leading to an overall drying out of Mars. The Mars Science Laboratory Curiosity rover has documented evidence at Gale for the periodic continuation of aqueous depositional processes within the Mount Sharp group within the Clay Sulfate Transition, suggesting that, in Gale crater, it was not a simple, unidirectional drying out pattern. We present data on a series of interdune lenses at Gale crater, providing a window into locally changing environmental conditions. They represent wet (fluvial to lacustrine) deposits in the otherwise dry eolian Contigo dune field. Alpha Particle X-Ray Spectrometer geochemical data reveal compositional similarities between the interdune lenses and both the host Contigo member and unaltered basaltic sediments. Modeling indicates that the lenses may contain up to 52% basaltic sands/soils mixed with local sediment. A high degree of homogeneity in composition and sedimentary structures are identified across the lenses. This suggests a common source of influx material and a repeated process (wet episodes in a dry environment over several cycles of seasonal variations). Furthermore, differences in composition between the interdune lenses and the host Contigo member help to elucidate the timing of alteration within the Mount Sharp group.
Date Issued
2025-11-01
Date Acceptance
2025-09-10
Citation
Journal of Geophysical Research: Planets, 2025, 130 (11)
ISSN
2169-9097
Publisher
American Geophysical Union
Journal / Book Title
Journal of Geophysical Research: Planets
Volume
130
Issue
11
Copyright Statement
© 2025. The Author(s). This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
10.1029/2025JE009001
Publication Status
Published
Article Number
e2025JE009001
Date Publish Online
2025-11-01