PETROGENETIC AND METALLOGENETIC AGES FOR THE PORPHYRY COPPER DEPOSITS IN THE GANGDISE METALLOGENIC BELT IN SOUTHERN TIBET  

作　　者：LI Guangming RUI Zongyao 

机构地区：[1]Chengdu Institute of Geology and Mineral Resources, Chengdu, SC 610082,China Institute of Mineral Resources,Chinese Academy of Geological Sciences, Beijing,100037,China

出　　处：《Geotectonica et Metallogenia》2004年第2期118-127,共10页大地构造与成矿学（英文版）

基　　金：jointly supported by China National Natural Science Foundation(Grant No.40272047);China National Key Basic Development Program(Grant No.(2002CB412609);large-scale Geological Survey Program of China Geological Survey(Project No.1212010330101).

摘　　要：Recent examination and assessment about the porphyry copper deposits in Gangdise metallogenic belt in southern Tibet have revealed that these porphyry copper deposits are highly prospective. Several methods have been used for the isotopic dating of the Qulong, Tinggong and Chongjiang porphyry copper deposits, which gives out a petrogenetic age of 17.58±0.74Ma (single-zircon dating of SHRIMP), a metallogenetic age of 15.99±0.32Ma (Re-Os isochron dating) and an alteration age ranging between 12.00Ma and 16.5Ma (K-Ar dating). The metallogenetic age is in general agreement with the alteration age. It can be seen that the petrogenetic and metallogenetic ages for the porphyry copper deposits in Gangdise metallogenic belt are noticeably later than the age for the collisional granitic intrusion in this belt. The authors contend that the porphyry copper deposits in the study area were formed in a post-collisional extensional tectonic setting, and are closely related to the delamination of the mountain roots of the orogenic belts and the uplifting of the Qinghai-Tibet Plateau.Recent examination and assessment about the porphyry copper deposits in Gangdise metallogenic belt in southern Tibet have revealed that these porphyry copper deposits are highly prospective. Several methods have been used for the isotopic dating of the Qulong, Tinggong and Chongjiang porphyry copper deposits, which gives out a petrogenetic age of 17.58±0.74Ma (single-zircon dating of SHRIMP), a metallogenetic age of 15.99±0.32Ma (Re-Os isochron dating) and an alteration age ranging between 12.00Ma and 16.5Ma (K-Ar dating). The metallogenetic age is in general agreement with the alteration age. It can be seen that the petrogenetic and metallogenetic ages for the porphyry copper deposits in Gangdise metallogenic belt are noticeably later than the age for the collisional granitic intrusion in this belt. The authors contend that the porphyry copper deposits in the study area were formed in a post-collisional extensional tectonic setting, and are closely related to the delamination of the mountain roots of the orogenic belts and the uplifting of the Qinghai-Tibet Plateau.

关 键 词：Tibet Gangdise METALLOGENIC belt PORPHYRY copper deposit ISOTOPIC dating significance 

分 类 号：P618.41[天文地球—矿床学]