HAO Jin-hua1,2,CHEN Jian-ping1,DONG Qing-ji1,WANG Tao3,LUO Zhi-zhong3
1.State Key laboratory of Geological Processes and Mineral Resource,Beijing 100083,China;
2.The Geological LAB Center,China University of Geosciences,Beijing 100083,China;3.Qinghai Geological Survey Institute,Xining 810012,China
Abstract: Lurige molybdenite-copper deposit is a newly discovered deposit in the northern Sanjiang polymetallic ore belt,southern Qinghai,China.This paper presents data of major elements,trace elements,Sr-Nr-Pb isotopes and petrological analyses and studies,the geochemical characteristics of the Lurige porphyries to reveals the origin,source area and tectonic background of formation of the porphyries.The geochemical data indicate that(1) the porphyries belong to the cal-alkaline series,(2) 87Sr/86Sr=(0.705 351～0.706 830),206Pb/204Pb=(19.2032～19.3650),207Pb/204Pb =(15.6850～15.6583),208Pb/204Pb =(39.2616～39.5228),(3) LREE and LILE are enriched in the porphyries,(4) the biotite granitic porphyries show weak Eu-deficit anomaly and the leucogranitic porphyries have strong Eu-deficit anomaly.These findings suggest that the source was probably located in the mantle-crust transition area,which was contaminated by the fluid carried in the subducted slab.The enriched magma was probably directed by the strike-slip fault system formed during the Indo-Asia collision in the Eocene,and then emplaced in the study area.
Key words: porphyry Mo-Cu deposit； element geochemistry； Sr-Nd-Pb isotopes； Lurige； southern Qinghai；
*Corresponding Author, E-Mail: haojh@cugb.edu.cn
Bulletin of Mineralogy, Petrology and Geochemistry Vol. 29, No.4, 2010, page 328-338
(Source from http://www.cnki.com.cn/)
