Communication Dans Un Congrès Année : 2023

Rippled to Bits: Tales of Transient Lakes in a Martian Desert

Edwin S. Kite
Juergen Schieber
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Aster Cowart
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John A. Grant
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Tex Kubacki
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Abigail Fraeman
Ashwin R. Vasavada

Résumé

The stratigraphy preserved within Aeolis Mons in Gale crater (Mars) shows a major transition from a 100s m thick package of phyllosilicate-bearing stratigraphic units recording deposition in lacustrine, fluvial, and aeolian settings, into a sulfate-bearing unit that is hundreds of meters thick (the Layered Sulfate-bearing unit (LSu). Comparison to other terrains on Mars has led to the hypothesis that this transition records a global change in climate from relatively warm and wet to cold and arid. Rover investigations by Curiosity have demonstrated that the sulfate-bearing strata record deposition in aeolian dune and sandsheet environments consistent with arid conditions. In late 2022, Curiosity investigated a distinctive meter-thick dark-toned, resistant unit even higher within the sulfate-bearing stratigraphy of Aeolis Mons – the “Marker Band”, informally designated the Amapari member of the Mirador formation (Mt. Sharp gp). This unit can be orbitally traced for tens of kilometers around Aeolis Mons. Within this unit, we specifically observe ensembles of alternating wavy-laminated structures and planar laminated beds, locally affected by the presence of nodules inferred to be diagenetic in origin. Laterally extensive wavy-laminated horizons are characterized by rounded crests and symmetrical short-wavelength (~5 cm) profiles, leading us to interpret them as probable oscillatory ripples produced by wind-generated waves action onto the surface of a shallow lake. The observation of multiple stacked wave-rippled bedsets within the Amapari mb. together with extensive bedding surface exposures of wave ripples demonstrates that this member represents deposition in a shallow lake body that intersected aeolian deposition. Our observations imply that arid desert systems that comprise the bulk of the Aeolis Mons Layered Sulfate-bearing unit was interrupted by establishment of lake systems either by rising groundwater or collecting upon mineralized surfaces of variable spatial extent that co-existed within the aeolian landscape.

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Dates et versions

hal-04286839 , version 1 (15-11-2023)

Identifiants

  • HAL Id : hal-04286839 , version 1

Citer

Sanjeev Gupta, William E. Dietrich, Kevin W. Lewis, Claire A. Mondro, Edwin S. Kite, et al.. Rippled to Bits: Tales of Transient Lakes in a Martian Desert. AGU Fall Meeting 2023, American Geophysical Union, Dec 2023, San Francisco (California), United States. pp.EP33B-07. ⟨hal-04286839⟩
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