湖北随州黑龙潭金矿石英Rb-Sr同位素年龄及其地质意义

发布时间：2018-05-13 05:18

本文选题：石英 + Rb-Sr定年　；参考：《地质通报》2017年05期

【摘要】：通过矿物流体包裹体Rb-Sr同位素测年,获得鄂北黑龙潭金矿石英Rb-Sr等时线年龄为132.6±2.7Ma,表明该金矿床形成于早白垩世中期。矿石石英中流体包裹体Sr同位素初始比(~(87)Sr/~(86)Sr)i平均值为0.710798,小于陆源硅酸盐的值(0.720),高于地幔Sr的初始值(0.707),暗示成矿物质来源于壳幔混合。结合各类岩矿石Au丰度变化,S、Pb、H、O等同位素组成,以及稀土和微量元素特征、成矿流体等研究,认为该矿床的形成可能与燕山期持续伸展阶段大规模构造-岩浆活动有关,燕山期中酸性岩浆活动为金矿成矿提供了主要矿源和热源。
[Abstract]:Based on the Rb-Sr isotopic dating of mineral fluid inclusions, a Rb-Sr isochron age of 132.6 卤2.7 Mais has been obtained, which indicates that the gold deposit was formed in the middle of early Cretaceous. The initial Sr isotopic ratio of fluid inclusions in quartz is 0.710798, which is smaller than that of continental silicate (0.720), and higher than that of mantle Sr (0.707), implying that the ore-forming material originates from crust-mantle mixing. Based on the study of au abundance variation and isotopic composition, rare earth and trace element characteristics, ore-forming fluid and so on, it is considered that the formation of the deposit may be related to the large-scale tectonic-magmatic activities in the Yanshanian continuous extensional stage. The acid magmatic activity in Yanshanian provides the main ore source and heat source for gold mineralization.
【作者单位】：中国地质调查局武汉地质调查中心;中国地质调查局花岗岩成岩成矿地质研究中心;
【基金】：中国地质调查局项目《武当-桐柏-大别成矿带资源远景调查评价》(编号:1212011220515)
【分类号】：P597.3;P618.51

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