皖南东源含W、Mo花岗闪长斑岩及成矿年代学研究

Characteristics and Geochronology of the W,Mo-bearing Granodiorite Porphyry in Dongyuan,Southern Anhui

在详细野外观察、剖面测量和研究分析的基础上,对＂江南古陆＂东段北缘的皖南祁门东源含W、Mo斑岩体进行了锆石U-Pb测年,重点讨论了成岩成矿关系和成矿物质来源。东源中细粒似斑状花岗闪长斑岩呈小岩株产出,SHR IMP锆石U-Pb测年结果为（146±1）M a,其内辉钼矿Re-Os同位素测年结果为（146.4±2.3）M a,成矿与岩体形成同期,均形成于晚侏罗世。辉钼矿的Re含量（22.02×10^-6-98.09×10^-6）指示成矿物质来源为壳幔混源。

Based on the field investigation,profiling and geochemical testing in detail,the systematic studies have been performed on geochronology of the Dongyuan W,Mo bearing granodiorite porphyry in southern Anhui.The Sensitive High Resolution Ion Micro Probe（SHRIMP） U-Pb zircon dating yields a concordant age of（146 ±1） Ma for granodiorite,suggesting that the intrusive body was formed during the Late Jurassic.While the Re Os dating result of 146 Ma shows that the molybdenite from the body was formed in the Late Jurassic,the same stage when the intrusive body formed.The content of Re from the molybdenite（22.02×10^-6-98.09×10^-6） shows that the ore forming materials are derived from the crust mantle mixed source.