Trace Element Mobility in Subducted Marble and Associated Eclogite:Constraints from UHP Rocks in the Shuanghe Area,Central-East China  

作　　者：Xingao Hou Zhiqiang Yu Shefa Chen Lei Liu Yilin Xiao 

机构地区：[1]Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,Ministry of Education,School of Geosciences and Info-Physics,Central South University,Changsha 410083,China [2]Key Laboratory of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China [3]CAS Key Laboratory of Crust-Mantle Materials and Environments,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China

出　　处：《Journal of Earth Science》2024年第1期1-15,共15页地球科学学刊（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.41972198);the Science and Technology Innovation Program of Hunan Province(No.2021RC4055);the Cooperation Foundation of Key Laboratory of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry;CAS(No.KLMM20180201);the Scientific Research Starting Foundation of Central South University。

摘　　要：In order to decipher element mobility in UHP meta-sedimentary rocks in the continental subduction zone,major and trace element compositions are investigated for a continuous profile from a representative UHP region in the Dabie Mountains.Among the lithologic contact zone,contents of K,Ca,LREE,and LILE exhibit varying degrees of downward trends in both marble and eclogite toward the contact zone,indicating that marble and their associated eclogite can release a large amount of K,Ca,and a small number of LILEs and LREEs.Titanite is the main Ti phase in both marble and eclogite.Titanite rims around rutile can occasionally be seen in eclogite.Contents of Ti and HFSE exhibit a well-coupled relation among marble and eclogite,indicating that substantial Ti and HFSEs were migrated from eclogite to marble,in accord with the capacity of a melt medium.Rutiles and titanites in marble exhibit a relatively limited variation in Nb/Ta ratios(12.9-16.2),similar to those of titanites in eclogite(14.2-16.7),which demonstrates that rutiles and titanites in marble were sourced from eclogite because of short-distance migrations of Ti and HFSEs.According to the P-T path and the temperature and pressure conditions of the peak metamorphism reported by previous studies,the eclogite associated with marble may not form supercritical fluids in the subduction zone because of the addition of carbonate minerals.

关 键 词：UHP metamorphism ECLOGITE MARBLE element migration fluid actions geochemistry 

分 类 号：P588.3[天文地球—岩石学] P597.3[天文地球—地质学] P542