Alternating wet and dry depositional environments recorded in the stratigraphy of Mount Sharp at Gale crater, Mars
Abstract
The Curiosity rover is exploring Hesperian-aged stratigraphy in Gale crater, Mars, where a transition from clay-bearing units to a layered sulfate-bearing unit has been interpreted to represent a major environmental transition of unknown character. We present the first description of key facies in the sulfate-bearing unit, recently observed in the distance by the rover, and propose a model for changes in depositional environments. Our results indicate a transition from lacustrine mudstones into thick aeolian deposits, topped by a major deflation surface, above which strata show architectures likely diagnostic of a subaqueous environment. This model offers a reference example of a depositional sequence for layered sulfate-bearing strata, which have been identified from orbit in other locations globally. It differs from the idea of a monotonic Hesperian climate change into long-term aridity on Mars and instead implies a period characterized by multiple transitions between sustained drier and wetter climates.
Additional Information
© 2021 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license. Manuscript received 19 October 2020; Revised manuscript received 18 January 2021; Manuscript accepted 21 January 2021. Rapin and Ehlmann were supported by a NASA Mars Science Laboratory (MSL) Participating Scientist grant to Ehlmann. The work of Dromart was supported by Centre National d'Etudes Spatiale (CNES) through the ChemCam Program. Data used are available in the NASA Planetary Data System (https://pds.nasa.gov/). The MSL project is supported by the NASA Mars Exploration Program and CNES. We thank K.M. Stack, M. Pondrelli, A. Owen, and one anonymous reviewer for help in improving this manuscript.Attached Files
Published - g48519.1.pdf
Supplemental Material - G48519_SuppFigs.pdf
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Additional details
- Eprint ID
- 108689
- Resolver ID
- CaltechAUTHORS:20210412-083509911
- NASA
- Centre National d'Études Spatiales (CNES)
- Created
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2021-04-13Created from EPrint's datestamp field
- Updated
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2021-07-06Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences