Hydrogen isotope geochemistry of lherzolitic shergottite in Martian meteorite GRV99027 from the Grove Mountains in Antarctica

Hydrogen isotopic composition was measured using an ion microprobe for lherzolitic shergottite in Martian meteorite GRV 99027 from the Grove Mountains in Antarctica. The D/H ratios of phosphate whitlockites were analyzed and water concentrations of tested points were calculated. The result show that their δ D values vary from +1300‰ to +4700‰, and water contents from 0.04 wt% to 0.43 wt%. Comparing the results with the hydrogen isotopic compositions of whole rock, hydrous miner- als and phosphates in SNC meteorites indicates that water highly enriched in deuterium is a unique feature of Martian meteorites, especially the phosphates prominent. It is interpreted as the result of isotopic exchange between magmatic water and Martian crustal fluids. The high D/H ratios observed in GRV 99027 phosphates indicate that they have hydrogen isotopic compositions similar to those of apatite in other Martian meteorites. The results further con- firmed the association of GRV 99027 with the Martian meteorite group.

Hydrogen isotopic composition was measured using an ion microprobe for Iherzolitic shergottite in Martian meteorite GRV 99027 from the Grove Mountains in Antarctica. The D/H ratios of phosphate whitlockites were analyzed and water concentrations of tested points were calculated. The result show that their δD values vary from ＋1300‰ to ＋4700‰, and water contents from 0.04 wt% to 0.43 wt%. Comparing the results with the hydrogen isotopic compositions of whole rock, hydrous minerals and phosphates in SNC meteorites indicates that water highly enriched in deuterium is a unique feature of Martian meteorites, especially the phosphates prominent. It is interpreted as the result of isotopic exchange between magmatic water and Martian crustal fluids. The high D/H ratios observed in GRV 99027 phosphates indicate that they have hydrogen isotopic compositions similar to those of apatite in other Martian meteorites. The results further confirmed the association of GRV 99027 with the Martian meteorite group.