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安徽铜陵老鸦岭矿床是一个典型的层状矿床,钼矿体赋存在二叠系顶部大隆组的碳质页岩-灰岩中.利用Re-Os同位素体系(ICP-MS方法)对该含钼岩层进行定年,得到的等时线年龄为234.27.3Ma,初始值为1.37?0.39(MSWD=1.5).该等时线年龄比沉积年龄(二叠纪末)年轻,其原因可能是:(1)后期热液的轻微扰动;(2)ICP-MS测量方式可能存在较大的质量分馏.但无论如何,该年龄接近沉积年龄,而远早于燕山晚期侵入岩侵位时代.因此老鸦岭钼矿床是同沉积型矿床,与燕山晚期岩浆活动无关.由于二叠纪的黑色页岩在长江中下游地区具有一定的分布,所以老鸦岭含钼黑色页岩的研究结果对认识长江中下游地区的成矿规律和开拓新的找矿方向有重要参考意义.
The Laoqialing deposit in Tongling, Anhui Province is a typical stratiform deposit, and the molybdenum ore body exists in the carbonaceous shale-limestone on the top Dalong Formation in the Permian. The Re-Os isotope system (ICP-MS method) Molybdenum stratigraphy, the isochron age is 234.27.3Ma and the initial value is 1.37 ~ 0.39 (MSWD = 1.5) .The ages are younger than the sedimentary age (Permian) .The reason may be: ( 1) slight perturbation of late hydrothermal fluids; (2) there may be a large mass fractionation by ICP-MS, but in any case, this age is close to the age of sedimentation, which is much earlier than that of the Late Yanshanian invasion emplacement. The molybdenum deposit is a sedimentary deposit of the same type and has nothing to do with the late Yanshan magmatic activity.Because the Permian black shale has a certain distribution in the middle and lower reaches of the Yangtze River, Of the metallogenic regularity and exploration of new prospecting direction has important reference value.