Shaler: insitu analysis of a fluvial sedimentary deposit on Mars - Université Claude Bernard Lyon 1 Access content directly
Journal Articles Sedimentology Year : 2018

Shaler: insitu analysis of a fluvial sedimentary deposit on Mars

Ralph E. Milliken
  • Function : Author
Michelle Minitti
  • Function : Author
Marisa Palucis
  • Function : Author
Melissa Rice
  • Function : Author
Scott K. Rowland
  • Function : Author
Juergen Schieber
  • Function : Author
Kathryn M. Stack
  • Function : Author
Dawn Y. Sumner
  • Function : Author
Roger C. Wiens
  • Function : Author
Rebecca M. E. Williams
  • Function : Author
Amy J. Williams
  • Function : Author
Lauren A. Edgar
  • Function : Author
Sanjeev Gupta
  • Function : Author
David M. Rubin
  • Function : Author
Kevin W. Lewis
  • Function : Author
Gary A. Kocurek
  • Function : Author
Ryan B. Anderson
  • Function : Author
James F. Bell
  • Function : Author
Kenneth S. Edgett
  • Function : Author
John P. Grotzinger
  • Function : Author
Craig Hardgrove
  • Function : Author
Linda C. Kah
  • Function : Author
Richard Leveille
  • Function : Author
Michael C. Malin
  • Function : Author
Nicolas Mangold

Abstract

This paper characterizes the detailed sedimentology of a fluvial sandbody on Mars for the first time and interprets its depositional processes and palaeoenvironmental setting. Despite numerous orbital observations of fluvial landforms on the surface of Mars, ground-based characterization of the sedimentology of such fluvial deposits has not previously been possible. Results from the NASA Mars Science Laboratory Curiosity rover provide an opportunity to reconstruct at fine scale the sedimentary architecture and palaeomorphology of a fluvial environment on Mars. This work describes the grain size, texture and sedimentary facies of the Shaler outcrop, reconstructs the bedding architecture, and analyses cross-stratification to determine palaeocurrents. On the basis of bedset geometry and inclination, grain-size distribution and bedform migration direction, this study concludes that the Shaler outcrop probably records the accretion of a fluvial barform. The majority of the outcrop consists of large-scale trough cross-bedding of coarse sand and granules. Palaeocurrent analyses and bedform reconstruction indicate that the beds were deposited by bedforms that migrated towards the north-east, across the surface of a bar that migrated south-east. Stacked cosets of dune cross-bedding suggest aggradation of multiple bedforms, which provides evidence for short periods of sustained flow during Shaler deposition. However, local evidence for aeolian reworking and the presence of potential desiccation cracks within the outcrop suggest that fluvial deposition may have been intermittent. The uppermost strata at Shaler are distinct in terms of texture and chemistry and are inferred to record deposition from a different sediment dispersal system with a contrasting provenance. The outcrop as a whole is a testament to the availability of liquid water on the surface of Mars in its early history.
Fichier principal
Vignette du fichier
sed.12370.pdf (19.37 Mo) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

hal-02327171 , version 1 (03-09-2021)

Licence

Attribution

Identifiers

Cite

Ralph E. Milliken, Michelle Minitti, Marisa Palucis, Melissa Rice, Scott K. Rowland, et al.. Shaler: insitu analysis of a fluvial sedimentary deposit on Mars. Sedimentology, 2018, 65 (1), pp.96--122. ⟨10.1111/sed.12370⟩. ⟨hal-02327171⟩
64 View
29 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More