Ages and geologic histories of Martian meteorites

  • Nyquist L
  • Bogard D
  • Shih C
 et al. 
  • 104

    Readers

    Mendeley users who have this article in their library.
  • 394

    Citations

    Citations of this article.

Abstract

We review the radiometric ages of the 16 currently known Martian meteorites, classified as 11 shergottites (8 basaltic and 3 lherzolitic), 3 nakhlites (clinopyroxenites), Chassigny (a dunite), and the orthopyroxenite ALH84001. The basaltic shergottites represent surface lava flows, the others magmas that solidified at depth. Shock effects correlate with these compositional types, and, in each case, they can be attributed to a single shock event, most likely the meteorite's ejection from Mars. Peak pressures in the range 15 – 45 GPa appear to be a "launch window": shergottites experienced ~30 – 45 GPa, nakhlites ~20 ± 5 GPa, Chassigny ~35 GPa, and ALH84001 ~35 – 40 GPa. Two meteorites, lherzolitic shergottite Y-793605 and orthopyroxenite ALH84001, are monomict breccias, indicating a two-phase shock history in toto: monomict brecciation at depth in a first impact and later shock metamorphism in a second impact, probably the ejection event.

Author-supplied keywords

  • Cosmic ray exposure ages
  • Crystallization ages
  • Ejection ages
  • Provenance
  • Shock effects

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text

Authors

  • L. E. Nyquist

  • D. D. Bogard

  • C. Y. Shih

  • A. Greshake

  • D. Stöffler

  • O. Eugster

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free