Nano SIMS analyses of apatite and melt inclusions in the GRV 020090 Martian meteorite:Hydrogen isotope evidence for recent past underground hydrothermal activity on Mars
作者单位：Key Laboratory of the Earth’s Deep InteriorInstitute of Geology and GeophysicsChinese Academy of Sciences National Astronomical ObservatoryChinese Academy of Sciences
会议名称：《中国科学院地质与地球物理研究所2014年度（第14届）学术年会》
会议日期：2015年
学科分类：070902[理学-地球化学] 0709[理学-地质学] 07[理学]
基 金：financially supported by the Natural Science Foundation of China (41273077 41221002 and 41103031)
摘 要：We measured the hydrogen isotopes and water contents of melt inclusions and apatite that locate far from shock-induced melt veins in the Martian meteorite GRV 020090,using nano-scale secondary ion mass spectrometry(nano SIMS).The melt inclusions in olivine show hydration profiles,with both the water contents and the d D values increasing from the cores(2r)(170±7 ppm and 3386±126&)to the rims(5337±200 ppm and 5519±65&).The extremely high d D values of the melt inclusions relative to a maximum of 4239±81&of apatite that crystallized from the last residual melt convincingly argue that the observed hydration postdated emplacement of the parent magma of GRV *** is also a robust line of evidence for past-presence of liquid water on *** simulation of the hydration profiles of both water contents and d D values constrains the duration of liquid water up to 130,000–250,000 years at 0°C or 700–1,500 years at 40°*** analyses of the melt inclusions,including the hydration profiles,show a logarithmic correlation between the water contents and the d D values,plotting within a two-endmember mixing *** extremely D-enriched endmember represents Martian underground water,with a d D value of 6034±72&(2r).This is the highest d D value reported in Martian meteorites and it is consistent with the recent analyses of Martian soils by the Curiosity rover(Leshin et al.,2013),suggestive of more water escaped from Mars than previous *** analyses of apatite show a distinct positive correlation between the water contents(0.10–0.58 wt%)and the d D values(737–4239&),which can be explained by assimilation of D-rich Martian crustal materials and enhancement of water via fractional *** observed correlation suggests that the water contents of Martian mantle reservoirs might have been overestimated from D-enriched apatite in previous *** estimation based on the least contaminated apatite grains from GRV 020090 turned out a low water content of