REE and Other Trace Element Chemistry of Oldhamite(CaS)in the Qingzhen Chondrite(EH3)and Their Genetic Implications  

作　　者：陈永亨 王道德 ERNST PERNICKA 

机构地区：[1]Institute of Geochemistry(Guangzhou Branch),Academia Sinica,Guangzhou,510640 [2]Max-Planck-Institut fur Kernphysik,6900 Heidelberg,Germany

出　　处：《Chinese Journal Of Geochemistry》1993年第4期317-327,共11页中国地球化学学报

基　　金：This project was financially supported by the National Natural Science Foundation of China.

摘　　要：Instrumental neutron activation analysis(INAA) of 14 single oldhamite grains separated from the Qingzhen chondrite (EH3) for refractory(La,Ce,Sm ,Eu,Yb,Lu,Ca,Sc,Hf, and Th),volatile (Na,Cr,Zn,Se,Br,etc.)and siderophile elements (Fe,Ni,Co,Ir,Au ,and As) revealed that oldhamite is highly rich in refractory elements.The mineral serves as the principal carrier of REE and contains about 80% of the REEs in the Qingzhen enstatite chondrite .Furthermore, the large enrichment of LREE relative to HREE is noticed in oldhamite from the Qingzhen .In general, the oldhamite from metal-sulfide assemblages is richer in REE than that from the matrix,i.e.,the earlier the oldhamite grains condensed, the richer they are in REE. Meanwhile.oldhamite is also rich in vol-atile elements such as Se,Br, etc.In terms of the distribution of trace elements in oldhamitc from the Qingzhen ,the chondrite is srggested to have resulted from high-temperature condensation of solar nebula.Instrumental neutron activation analysis(INAA)of 14 single oldhamite grams separated from the Qingzhen chondrite(EH3)for refractory(La,Ce.Sin,Eu,Yb,Lu,Ca,Sc,Hf,and Th),volatile (Na,Cr,Zn,Se,Br,ctc.)and sidcrophile elements(Fe,Ni,Co,Ir,Au,and As)revealed that oldhamite is highly rich in refractory elements.The mineral serves as the principal carrier of REE and contains about 80% of thc REEs in the Qingzhen enstatite chondrite.Furthermore,the large enrichment of LREE relative to HREE is noticed in oldhamite from the Qingzhen.In gencral,the oldhamite from metal-sulfide assemblages is richer in REE than that from the matrix,i.e.,the earlier the oldhamite grains condensed,the richer they are in REE.Meanwhile,oldhamite is also rich in vol- atile elements such as Se,Br,etc.In terms of the distribution of trace elements in oldhamite from the Qingzhen,the chondrite is suggested to have resutled from high-temperature condensation of solar nebula.

关 键 词：球粒状陨石 硫化物 示踪元素 稀土元素 中子活化分析 顽辉石 

分 类 号：P578.2[天文地球—矿物学] P68[天文地球—地质学]