Elemental Geochemistry of Sedimentary Rocks at Yellowknife Bay, Gale Crater, Mars

Research areas:
Year:
2014
Authors:
  • S. M. McLennan
  • R. B. Anderson
  • J. F. Bell
  • J. C. Bridges
  • F. Calef
  • J. L. Campbell
  • B. C. Clark
  • S. Clegg
  • P. Conrad
  • A. Cousin
  • D. J. Des Marais
  • G. Dromart
  • M. D. Dyar
  • L. A. Edgar
  • B. L. Ehlmann
  • C. Fabre
  • O. Forni
  • O. Gasnault
  • R. Gellert
  • S. Gordon
  • J. A. Grant
  • J. P. Grotzinger
  • S. Gupta
  • K. E. Herkenhoff
  • J. A. Hurowitz
  • P. L. King
  • Stéphane Le Mouélic
  • L. A. Leshin
  • R. Leveille
  • K. W. Lewis
  • Nicolas Mangold
  • S. Maurice
  • D. W. Ming
  • R. V. Morris
  • Marion Nachon
  • H. E. Newsom
  • A. M. Ollila
  • G. M. Perrett
  • M. S. Rice
  • M. E. Schmidt
  • S. P. Schwenzer
  • K. Stack
  • E. M. Stolper
  • D. Y. Sumner
  • A. H. Treiman
  • S. VanBommel
  • D. T. Vaniman
  • A. Vasavada
  • R. C. Wiens
  • R. A. Yingst
  • MSL Sci Team
Journal:
SCIENCE
Volume:
343
Number:
6169
Month:
JAN 24
ISSN:
0036-8075
Abstract:
Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay,
Mars, were derived from sources that evolved from an approximately
average martian crustal composition to one influenced by alkaline
basalts. No evidence of chemical weathering is preserved, indicating
arid, possibly cold, paleoclimates and rapid erosion and deposition. The
absence of predicted geochemical variations indicates that magnetite and
phyllosilicates formed by diagenesis under low-temperature,
circumneutral pH, rock-dominated aqueous conditions. Analyses of
diagenetic features (including concretions, raised ridges, and
fractures) at high spatial resolution indicate that they are composed of
iron-and halogen-rich components, magnesium-iron-chlorine-rich
components, and hydrated calcium sulfates, respectively. Composition of
a cross-cutting dike-like feature is consistent with sedimentary
intrusion. The geochemistry of these sedimentary rocks provides further
evidence for diverse depositional and diagenetic sedimentary
environments during the early history of Mars.