安徽省池州地区马头钼矿辉钼矿Re-Os年龄及其地质意义  

Re-Os ISOTOPIC DATING OF MOLYBDENITE FROM THE MATOU IINDGRENITE DEPOSIT FROM CHIZHOU AREA IN THE SOUTH OF ANHUI PROVINCE AND ITS GEOLOGICAL IMPLICATIONS

作　　者：杨贵才[1,2] 葛良胜[2] 路英川[1,2] 邹依林[2] 邢俊兵[1,2] 张峰[1,2] 袁士松[1,2] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]武警黄金地质研究所,河北廊坊065000

出　　处：《矿物岩石》2014年第1期30-35,共6页Mineralogy and Petrology

基　　金：武警黄金指挥部重点地质科研项目(HJ10-02;HJ09-12)

摘　　要：安徽马头钼矿是长江中下游安庆-池州矿集区一个中型钼矿床。利用辉钼矿Re-Os同位素测年技术,分别对马头钼矿床中1件斑岩型矿石和1件砂板岩型矿石中辉钼矿进行定年,首次获得马头钼矿床成矿年龄。两件矿石的模式年龄分别为148.6 Ma±2.1Ma和150.2Ma±2.7Ma,算术平均值为149.2Ma±3.2Ma,两者在误差范围内,也与马头钼矿关系密切的花岗闪长斑岩锆石U-Pb年龄(147Ma±2Ma)一致,因此149 Ma±3.2Ma代表了马头钼矿的成矿时代。两件样品辉钼矿Re含量分别为134×10-6,421×10-6,指示成矿物质主要来自于地幔,混有少量的地壳物质。长江中下游铜金多金属矿床的成矿时间通常认为是145Ma^125Ma之间,马头钼矿和池州地区其他多金属矿床一致的成岩成矿年龄,表明在长江中下游地区在150Ma左右可能存在与中国东部由东西向构造体系向北北东向构造体系转变相关的一次成矿事件。The Matou lindgrenite deposit in Anhui Province is a porphyry deposit in the Anqing- Chizhou area of the Middle-Lower Yangtze River Valley,Eastern China. Two Re-Os isotopic dat- ing on molybdenites collected from the granodiorite porphyry ores and the Fentou Formation sandy slate ores yield a Re-Os model age of 148.6 Ma! 2.1 Ma and 150.2 Ma! 2.7 Ma respec- tively, with an average age of 149.2 Ma^3.2 Ma,showing good agreement with the zircon U-Pb age of granodiorite porphyry （147 Ma＋ 2 Ma）. Therefore,149.2 Ma_--4-3.2 Ma can represent the forming age of the Matou lindgrenite deposit. This ore-forming age is different from isotopic dat- ing results （145 Ma^125 Ma） provided by earlier workers in the area. The Re content in molyb- denites of Matou lindgrenite deposit is 134X 10 6 and 421 〉 10-6 ,indicating that the ore-forming material is mainly originated from the mantle. The determination of the rock-forming ages and ore-forming ages （in late Jurassic） of Matou lindgrenite deposit and other polymetallic deposits in the Middle-Lower Yangtze River Valley suggests these deposits may be formed under the same geodynamics setting of the tectonic transition from the EW trend tectonic domain tO the NNE trend tectonic domain in east China.

关 键 词：RE-OS同位素年龄 马头钼矿 池州地区 长江中下游 

分 类 号：P597.10[天文地球—地球化学] P618.2[天文地球—地质学]