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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。
Anhui Ma Tau Molybdenum is the middle and lower reaches of the Yangtze River Anqing - Chizhou ore district a medium-sized molybdenum deposits. Using the molybdenite Re-Os isotope dating technique, the molybdenite in one porphyry ore and one sandstone-type ore in the Matou molybdenum deposit are respectively dated, and the metallogenic age of the Ma-Tou molybdenum deposit is obtained for the first time. The model ages of the two ores are 148.6 Ma ± 2.1Ma and 150.2Ma ± 2.7Ma, respectively, and the arithmetic average is 149.2Ma ± 3.2Ma. Both of them are within the error range and are also closely related to the horse head molybdenum mine. The porphyry zircon U-Pb ages (147 Ma ± 2 Ma) are consistent, so 149 Ma ± 3.2 Ma represents the mineralization age of the Ma Tau molybdenum deposit. The Re contents of the two samples of molybdenite are 134 × 10-6 and 421 × 10-6, respectively, indicating that the ore-forming materials mainly come from the mantle, mixed with a small amount of crustal material. The metallogenic time of the copper-gold polymetallic deposits in the middle and lower reaches of the Yangtze River is generally considered to be between 145Ma and 125Ma. The age of diagenesis and mineralization of Matou molybdenum and other polymetallic deposits in Chizhou area indicates that there may be some 150Ma in the middle and lower reaches of the Yangtze River A metallogenic event related to the transition from the east-west structural system to the north-north-eastern structural system in eastern China.