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鄂东南地区Cu-Au-Mo-(W)矿床是长江中下游地区金属成矿带的重要组成部分。本文利用Re-Os同位素定年方法对该地区5个典型矿床(丰山洞铜钼金银多金属矿床、阮家湾钨铜钼矿床、千家湾铜金矿床、铜绿山铜铁金钼多金属矿床和铜山口铜钼矿床)进行了成矿时代的研究,获得其辉钼矿Re-Os同位素年龄分别为(144.0±2.1)Ma、(143.6±1.7)Ma、(137.7±1.7)Ma、(137.8±1.7)~(138.1±1.8)Ma和(143.5±1.7)~(142.3±1.8)Ma,代表各矿床的成矿时代。研究结果表明,鄂东南矿集区内的Cu-Au-Mo-(W)矿床与铜陵、安庆、九瑞矿集区内的矿床几乎是同时形成的,成矿时代可能主要集中于(140±5)Ma,相当于晚侏罗世-早白垩世。在综合已有的岩石学、地球化学和地球物理学资料的基础上,笔者认为,这一成矿事件的深部动力学过程可能是处于中国东部南北向印支期构造域向北东向古太平洋构造域大转折的背景下,与软流圈上涌和玄武质岩浆底侵而导致壳幔同熔有关。
The Cu-Au-Mo- (W) deposit in southeastern Hubei is an important part of the metallogenic belt in the middle and lower reaches of the Yangtze River. In this paper, we use the Re-Os isotopic dating method to study five typical deposits in the area (Fengsandong Cu-Mo-Au polymetallic deposit, Ruanjiawan Tungsten Cu-Mo deposit, Qianjiawan Cu-Au deposit, Tonglushan Cu-Fe- (144.0 ± 2.1) Ma, (143.6 ± 1.7) Ma, (137.7 ± 1.7) Ma, (137.8 ± 1.7) Ma, respectively. The mineralization age of the molybdenite ore was 1.7) ~ (138.1 ± 1.8) Ma and (143.5 ± 1.7) ~ (142.3 ± 1.8) Ma, representing the mineralization age of each deposit. The results show that the Cu-Au-Mo- (W) deposits in the southeastern part of Hubei Province are almost simultaneously formed with the deposits in the Tongling, Anqing and Jiuui ore areas, and the mineralization age may be mainly in the region of (140 ± 5) Ma, equivalent to Late Jurassic - Early Cretaceous. Based on the comprehensive data of petrology, geochemistry and geophysics, the author believes that the deep kinetic process of this metallogenic event may be located in the Indosinian tectonic domain in the northwestern part of China to the northeast to the ancient Pacific In the background of the great turning of tectonic domain, it is related to the upwelling of asthenosphere and the basaltic magma intrusion, leading to the same crust-mantle melting.