The Chemostratigraphy of the Murray Formation and Role of Diagenesis at Vera Rubin Ridge in Gale Crater, Mars, as Observed by the ChemCam Instrument

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Documents

  • N. Mangold
  • R. C. Wiens
  • A. A. Fraeman
  • L. A. Edgar
  • C. M. Fedo
  • J. L'Haridon
  • C. C. Bedford
  • Sanjeev Gupta
  • J. P. Grotzinger
  • J. C. Bridges
  • B. C. Clark
  • E. B. Rampe
  • O. Gasnault
  • S. Maurice
  • P. J. Gasda
  • N. L. Lanza
  • A. M. Olilla
  • P. Y. Meslin
  • V. Payré
  • F. Calef
  • Mark Salvatore
  • C. H. House

Geochemical results are presented from Curiosity's exploration of Vera Rubin ridge (VRR), in addition to the full chemostratigraphy of the predominantly lacustrine mudstone Murray formation up to and including VRR. VRR is a prominent ridge flanking Aeolis Mons (informally Mt. Sharp), the central mound in Gale crater, Mars, and was a key area of interest for the Mars Science Laboratory mission. ChemCam data show that VRR is overall geochemically similar to lower-lying members of the Murray formation, even though the top of VRR shows a strong hematite spectral signature as observed from orbit. Although overall geochemically similar, VRR is characterized by a prominent decrease in Li abundance and Chemical Index of Alteration across the ridge. This decrease follows the morphology of the ridge rather than elevation and is inferred to reflect a nondepositionally controlled decrease in clay mineral abundance in VRR rocks. Additionally, a notable enrichment in Mn above baseline levels is observed on VRR. While not supporting a single model, the results suggest that VRR rocks were likely affected by multiple episodes of postdepositional groundwater interactions that made them more erosionally resistant than surrounding Murray rocks, thus resulting in the modern-day ridge after subsequent erosion.

Original languageEnglish
Article numbere2019JE006320
JournalJournal of Geophysical Research: Planets
Volume125
Issue number9
Pages (from-to)1-21
ISSN2169-9097
DOIs
Publication statusPublished - 2020

    Research areas

  • ChemCam, chemostratigraphy, Gale crater, Mars, Mars Science Laboratory, Vera Rubin ridge

ID: 249475465