Slightly Weathered Boulder on MarsSlightly Weathered Boulder on Mars

COSMOCHEMISTRY iLLUSTRATEDWeathering Rinds on Mars

“Humphrey”, Gusev Crater, Mars

~30 cm

NASA/JPL/Cornell

Weathering Rinds, Earth and MarsWeathering Rinds, Earth and Mars

COSMOCHEMISTRY iLLUSTRATEDWeathering Rinds on Mars

Sak et al. (2004) McSween et al. (2004)

Weathering rinds on a terrestrial boulder (Costa Rica) and on the Humphrey boulder on Mars.

~0.5 cm

Quantification of Rind FormationQuantification of Rind Formation

COSMOCHEMISTRY iLLUSTRATEDWeathering Rinds on Mars

Reaction transport models indicate minimum weathering times of at least 22 x 103 years for Humphrey.

Hausrath et al. (2008)