Clay mineral diversity and abundance in sedimentary rocks of Gale crater, Mars

Research areas:
Year:
2018
Authors:
  • Thomas F. Bristow
  • Elizabeth B. Rampe
  • Cherie N. Achilles
  • David F. Blake
  • Steve J. Chipera
  • Patricia Craig
  • Joy A. Crisp
  • David J. Des Marais
  • Robert T. Downs
  • Ralf Gellert
  • John P. Grotzinger
  • Sanjeev Gupta
  • Robert M. Hazen
  • Briony Horgan
  • Joanna V. Hogancamp
  • Nicolas Mangold
  • Paul R. Mahaffy
  • Amy C. McAdam
  • Doug W. Ming
  • John Michael Morookian
  • Richard V. Morris
  • Shaunna M. Morrison
  • Allan H. Treimans
  • David T. Vanimanm
  • Ashwin R. Vasavada
  • Albert S. Yen
Journal:
SCIENCE ADVANCES
Volume:
4
Number:
6
Month:
June
ISSN:
2375-2548
BibTex:
Abstract:
Clay minerals provide indicators of the evolution of aqueous conditions
and possible habitats for life on ancient Mars. Analyses by the Mars
Science Laboratory rover Curiosity show that similar to 3.5-billion year
(Ga) fluvio-lacustrine mudstones in Gale crater contain up to similar to
28 weight \% (wt \%) clay minerals. We demonstrate that the species of
clay minerals deduced from x-ray diffraction and evolved gas analysis
show a strong paleoenvironmental dependency. While perennial lake
mudstones are characterized by Fe-saponite, we find that stratigraphic
intervals associated with episodic lake drying contain Al-rich,
Fe3+-bearing dioctahedral smectite, with minor (3 wt \%) quantities of
ferripyrophyllite, interpreted as wind-blown detritus, found in
candidate aeolian deposits. Our results suggest that dioctahedral
smectite formed via near-surface chemical weathering driven by
fluctuations in lake level and atmospheric infiltration, a process
leading to the redistribution of nutrients and potentially influencing
the cycling of gases that help regulate climate.