Where were the Metal, Sulfur and Water from in the Postcollisional Porphyry Cu Deposit at Qulong in South Tibet?  

作　　者：QU Huanchun SUN Maoyu 

机构地区：[1]School of Earth Science and Resource, China University of Geosciences (Beijing) [2]Institute of Geology, Chinese Academy of Geological Sciences

出　　处：《Acta Geologica Sinica(English Edition)》2016年第2期753-754,共2页地质学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(grant No.41273051)

摘　　要：Objective Most porphyry Cu deposits （PCDs） were formed in association with subduction-related calc-alkaline magmas, which occurred widely in magmatic arcs worldwide. A widely accepted model is that such deposits were formed from hydrothermal fluids exsolved from hydrous, high oxygen fugacity, sulfur-rich arc magmas, derived from a mantle wedge metasomatized by subduction-slab fluids. Recent studies have documented that such deposits may also occur in post-collisional settings, e.g., the Gangdese porphyry Cu belts in Tibet. The formation of such PCDs is very difficult to be explained by the classic PCDs model, which results in an alternative model to be proposed to interpret the genesis of PCDs in such settings. In this alternative model, metals and sulfur of the post-collisional PCDs were generally thought to be derived from a subduction-modified thickened lower crust, rather than a metasomatized mantle wedge. However, our detailed analysis suggests that the sources of metals and sulfur for the PCDs in post-collisional settings still cannot be well explained by the lower-crust melting model.Objective Most porphyry Cu deposits （PCDs） were formed in association with subduction-related calc-alkaline magmas, which occurred widely in magmatic arcs worldwide. A widely accepted model is that such deposits were formed from hydrothermal fluids exsolved from hydrous, high oxygen fugacity, sulfur-rich arc magmas, derived from a mantle wedge metasomatized by subduction-slab fluids. Recent studies have documented that such deposits may also occur in post-collisional settings, e.g., the Gangdese porphyry Cu belts in Tibet. The formation of such PCDs is very difficult to be explained by the classic PCDs model, which results in an alternative model to be proposed to interpret the genesis of PCDs in such settings. In this alternative model, metals and sulfur of the post-collisional PCDs were generally thought to be derived from a subduction-modified thickened lower crust, rather than a metasomatized mantle wedge. However, our detailed analysis suggests that the sources of metals and sulfur for the PCDs in post-collisional settings still cannot be well explained by the lower-crust melting model.

关 键 词：Where were the Metal Sulfur and Water from in the Postcollisional Porphyry Cu Deposit at Qulong in South Tibet CU 

分 类 号：P618.41[天文地球—矿床学]