Thursday, June 03, 2010

Carbonates suggest warmer, wetter Mars

ASU planetary scientist Steven Ruff is second author on a study to be published tomorrow in Science that concludes carbonates are more widespread than previously thought, lending credence to the theory that Mars had a warmer, wetter climate and CO2-rich atmosphere in it's early history. [right, "Comanche" outcrop on Mars. Credit, NASA/JPL/Cornell]

The abstract says:
Such an atmosphere should have led to the formation of outcrops rich in carbonate minerals, for which evidence has been sparse. Using the Mars Exploration Rover (MER) Spirit, we have now identified outcrops rich in Mg-Fe carbonate (16 to 34 wt.%) in the Columbia Hills of Gusev crater. Its composition approximates the average composition of the carbonate globules in Martian meteorite ALH 84001. The Gusev carbonate probably precipitated from carbonate-bearing solutions under hydrothermal conditions at near-neutral pH in association with volcanic activity during the Noachian era
Ref: Morris, R. V. et al. Identification of Carbonate-Rich Outcrops on Mars by the Spirit Rover, Science doi 10.1126/science.1189667 (2010).

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