In situ detection of boron by ChemCam on Mars

We report the first in situ detection of boron on Mars. Boron has been detected in Gale crater at levels Curiosity rover ChemCam instrument in calcium-sulfate-filled fractures, which formed in a late-stage groundwater circulating mainly in phyllosilicate-rich bedrock interpreted as lacustrine in origin. We consider two main groundwater-driven hypotheses to explain the presence of boron in the veins: leaching of borates out of bedrock or the redistribution of borate by dissolution of borate-bearing evaporite deposits. Our results suggest that an evaporation mechanism is most likely, implying that Gale groundwaters were mildly alkaline. On Earth, boron may be a necessary component for the origin of life; on Mars, its presence suggests that subsurface groundwater conditions could have supported prebiotic chemical reactions if organics were also present and provides additional support for the past habitability of Gale crater

First detection of fluorine on Mars: Implications for Gale Crater's geochemistry

International audienceVolatiles and especially halogens (F and Cl) have been recognized as important species in thegenesis and melting of planetary magmas. Data from the Chemical Camera instrument on board the MarsScience Laboratory rover Curiosity now provide the first in situ analyses of fluorine at the surface of Mars. Twoprincipal F-bearing mineral assemblages are identified. The first is associated with high aluminum and lowcalcium contents, in which the F-bearing phase is an aluminosilicate. It is found in conglomerates and mayindicate petrologically evolved sources. This is the first time that such a petrologic environment is found onMars. The second is represented by samples that have high calcium contents, in which the main F-bearingminerals are likely to be fluorapatites and/or fluorites. Fluorapatites are found in some sandstone and may bedetrital, while fluorites are also found in the conglomerates, possibly indicating low-T alteration processes