GRS evidence and the possibility of paleooceans on Mars

James M. Dohm, Victor R. Baker, William V. Boynton, Alberto G. Fairén, Justin C. Ferris, Michael Finch, Roberto Furfaro, Trent M. Hare, Daniel M. Janes, Jeffrey S. Kargel, Suniti Karunatillake, John Keller, Kris Kerry, Kyeong J. Kim, Goro Komatsu, William C. Mahaney, Dirk Schulze-Makuch, Lucia Marinangeli, Gian G. Ori, Javier RuizShawn J. Wheelock

Research output: Contribution to journalArticlepeer-review

69 Scopus citations


The Gamma Ray Spectrometer (Mars Odyssey spacecraft) has revealed elemental distributions of potassium (K), thorium (Th), and iron (Fe) on Mars that require fractionation of K (and possibly Th and Fe) consistent with aqueous activity. This includes weathering, evolution of soils, and transport, sorting, and deposition, as well as with the location of first-order geomorphological demarcations identified as possible paleoocean boundaries. The element abundances occur in patterns consistent with weathering in situ and possible presence of relict or exhumed paleosols, deposition of weathered materials (salts and clastic minerals), and weathering/transport under neutral to acidic brines. The abundances are explained by hydrogeology consistent with the possibly overlapping alternatives of paleooceans and/or heterogeneous rock compositions from diverse provenances (e.g., differing igneous compositions).

Original languageEnglish (US)
Pages (from-to)664-684
Number of pages21
JournalPlanetary and Space Science
Issue number5-6
StatePublished - May 2009


  • Elemental
  • Gamma-ray spectrometer
  • Hydrogeology
  • Mars
  • Oceans
  • Water

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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