Some refractory and volatile element chemistry of CaS in enstatite chondrites  

作　　者：陈永亨 Paul H.Benoit 

机构地区：[1]Guangzhou Institute of Geochemistry, Chinese Academy of Sciences. Guangzhou 510640, China [2]Cosmochemistry Group, Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR72701, USA

出　　处：《Science China Earth Sciences》1996年第2期184-193,共10页中国科学（地球科学英文版）

基　　金：Project supported by the National Natural Science Foundation of China.

摘　　要：INAA data for REE, Sc, Se, Br and Zn in CaS extracted from 5 enstatite chondrites (Qingzhen EH3, St. Marks EH5, Atlanta EL6, Hvittis EL6 and Pillistfer EL6) are reported. The results indicate that the REE abundances in CaS from unequilibrated enstatite chondrite, Qingzhen, are much higher than that from equilibrated ones. Similarly, the abundances of Sc, Se, Br and Zn in CaS from Qingzhen are higher than that in CaS grains from equilibrated chondrites, revealing that CaS is a previous condensate and is not simple residues of an evaporative process. Secondly, metamorphism has caused the redistribution of the trace elements among the minerals in enstatite chondrites, and this metamorphic fractionation reflects the differences from element volatilities and chemical properties. The REE patterns of CaS of enstatite chondrites and aubrites could not explain that aubrites were derived from known enstatite chondrites by igneous processing. And depleted europium in metamorphism and igneous process may be carried by Cr-bearing sulfides (minerals A and B).INAA data for REE, Sc, Se, Br and Zn in CaS extracted from 5 enstatite chondrites (Qingzhen EH3, St. Marks EH5, Atlanta EL6, Hvittis EL6 and Pillistfer EL6) are reported. The results indicate that the REE abundances in CaS from unequilibrated enstatite chondrite, Qingzhen, are much higher than that from equilibrated ones. Similarly, the abundances of Sc, Se, Br and Zn in CaS from Qingzhen are higher than that in CaS grains from equilibrated chondrites, revealing that CaS is a previous condensate and is not simple residues of an evaporative process. Secondly, metamorphism has caused the redistribution of the trace elements among the minerals in enstatite chondrites, and this metamorphic fractionation reflects the differences from element volatilities and chemical properties. The REE patterns of CaS of enstatite chondrites and aubrites could not explain that aubrites were derived from known enstatite chondrites by igneous processing. And depleted europium in metamorphism and igneous process may be

关 键 词：ENSTATITE METEORITES oldhamite TRACE element chemistry INVA. 

分 类 号：P59[天文地球—地球化学]