Cosmic-ray exposure age of Martian meteorite GRV 99027  

作　　者：D. FABEL R. BROWN S. FREEMAN 

机构地区：[1]Department of Geographical and Earth Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK [2]Scottish Universities Environmental Research Centre, Rankine Avenue, Scottish Enterprise Technology Park, East Kilbride G75 0QF, Scotland, UK

出　　处：《Science China Earth Sciences》2007年第10期1521-1524,共4页中国科学（地球科学英文版）

基　　金：National Natural Science Foundation of China (Grant Nos. 40673054 and 40232026)

摘　　要：We have determined the concentrations of 10Be and 26Al in GRV 99027 recovered by the 16th Chinese Antarctic expedition team, which are 14.1 ± 0.6 dpm/kg and 67.5 ± 3.4 dpm/kg, respectively. From the concentration of 10Be, we calculate a cosmic-ray exposure age of 4.4 ± 0.6 Ma for GRV 99027. The concentration of 26Al is too high compared to the 10Be exposure age, indicating extra production from solar ray. The exposure ages, petrologic and geochemical characteristics of mantle-derived Martian meteorites GRV 99027, LEW 88516, Y-793605, NWA 1950 and ALHA77005 are very similar, suggesting that these meteorites most probably were ejected from Mars in the same impact event.We have determined the concentrations of 10Be and 26Al in GRV 99027 recovered by the 16th Chinese Antarctic expedition team, which are 14.1 ± 0.6 dpm/kg and 67.5 ± 3.4 dpm/kg, respectively. From the concentration of 10Be, we calculate a cosmic-ray exposure age of 4.4 ± 0.6 Ma for GRV 99027. The concentration of 26Al is too high compared to the 10Be exposure age, indicating extra production from solar ray. The exposure ages, petrologic and geochemical characteristics of mantle-derived Martian meteorites GRV 99027, LEW 88516, Y-793605, NWA 1950 and ALHA77005 are very similar, suggesting that these meteorites most probably were ejected from Mars in the same impact event.

关 键 词：GRV 99027  Martian meteorite  COSMIC ray  exposure age  MARS 

分 类 号：P185.83[天文地球—天文学]