Presolar grains in the CM2 chondrite Sutter's Mill
作者单位：Key Laboratory of the Earth’s Deep InteriorInstitute of Geology and GeophysicsChinese Academy of Sciences Department of Earth and Planetary SciencesUniversity of California at Davis ARESNASA Johnson Space Center SETI InstituteMountain View NASA Ames Research CenterMoffett Field
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：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 070401[理学-天体物理] 0704[理学-天文学]
基 金：supported by the Natural Science Foundation of China (40830421,41173075) the State Key Laboratory of Lithospheric Evolution (IGG-CAS Grant Z201003)
摘 要：The Sutter’s Mill(SM)carbonaceous chondrite is a regolith breccia,composed predominantly of CM2 clasts with varying degrees of aqueous alteration and thermal *** investigation of presolar grains in four Sutter’s Mill sections,SM43,SM51,SM2-4,and SM18,was carried out using Nano SIMS ion mapping technique.A total of 37 C-anomalous grains and one O-anomalous grain have been identified,indicating an abundance of 63 ppm for presolar C-anomalous grains and 2 ppm for presolar ***-one silicon carbide(Si C),five carbonaceous grains,and one Al-oxide(Al2O3)were confirmed based on their elemental compositions determined by C-N-Si and O-Si-Mg-Al isotopic *** overall abundance of Si C grains in Sutter’s Mill(55 ppm)is consistent with those in other CM *** absence of presolar silicates in Sutter’s Mill suggests that they were destroyed by aqueous alteration on the parent ***,SM2-4 shows heterogeneous distributions of presolar Si C grains(12–54 ppm)in different matrix areas,indicating that the fine-grained matrix clasts come from different sources,with various thermal histories,in the solar nebula.