Mineralogy of the Paso Robles soils on Mars

Melissa D. Lane*, Janice L. Bishop, M. Darby Dyar, Penelope L. King, Mario Parente, Brendt C. Hyde

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

82 Citations (Scopus)


Visible, near-infrared, thermal, and Mössbauer spectroscopic data from the exposed, bright track soil at the "Paso Robles" site within Gusev crater, Mars, indicate the presence of Fel3+-sulfates and possibly Fe3+-phosphates admixed with the host soil. When the spectroscopic analyses are combined with constraints imposed by chemical data, the determined dominant Fe3+-sulfate component is hydrous, and all of the spectroscopic methods suggest that it is probably ferricopiapite or some closely related, structurally similar species, possibly mixed with other Fe3+ sulfates such as butlerite or parabutlerite, or perhaps (para)coquimbite, fibroterrite, or metahohmanite. Such an assemblage is consistent with formation in a highly oxidized, relatively dehydrated environment with the bulk-sulfate assemblage having OH/(OH + 2SO4) of < ∼0.4. Some Fe3+ is likely to be associated with phosphates in the soil in the form of ferristrunzite or strengite.

Original languageEnglish
Pages (from-to)728-739
Number of pages12
JournalAmerican Mineralogist
Issue number5-6
Publication statusPublished - 2008
Externally publishedYes


Dive into the research topics of 'Mineralogy of the Paso Robles soils on Mars'. Together they form a unique fingerprint.

Cite this