Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Orbital Identification of Carbonate-Bearing Rocks on Mars

Bethany L. Ehlmann, John F. Mustard, Scott L. Murchie, Francois Poulet, Janice L. Bishop, Adrian J. Brown, Wendy M. Calvin, Roger N. Clark, David J. Des Marais, Ralph E. Milliken, Leah H. Roach, Ted L. Roush, Gregg A. Swayze and James J. Wray
Science
New Series, Vol. 322, No. 5909 (Dec. 19, 2008), pp. 1828-1832
Stable URL: http://www.jstor.org/stable/20177071
Page Count: 5
  • More info
  • Cite this Item
Orbital Identification of Carbonate-Bearing Rocks on Mars
Preview not available

Abstract

Geochemical models for Mars predict carbonate formation during aqueous alteration. Carbonate-bearing rocks had not previously been detected on Mars' surface, but Mars Reconnaissance Orbiter mapping reveals a regional rock layer with near-infrared spectral characteristics that are consistent with the presence of magnesium carbonate in the Nili Fossae region. The carbonate is closely associated with both phyllosilicate-bearing and olivine-rich rock units and probably formed during the Noachian or early Hesperian era from the alteration of olivine by either hydrothermal fluids or near-surface water. The presence of carbonate as well as accompanying clays suggests that waters were neutral to alkaline at the time of its formation and that acidic weathering, proposed to be characteristic of Hesperian Mars, did not destroy these carbonates and thus did not dominate all aqueous environments.

Page Thumbnails

  • Thumbnail: Page 
1828
    1828
  • Thumbnail: Page 
1829
    1829
  • Thumbnail: Page 
1830
    1830
  • Thumbnail: Page 
1831
    1831
  • Thumbnail: Page 
1832
    1832