大别造山带核部罗田陈林沟金矿成矿时代
METALLOGENETIC EPOCH OF CHENLINGOU GOLD DEPOSIT IN THE CORE OF DABIESHAN OROGENIC BELT, LUOTIAN, HUBEI PROVINCE
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摘要: 大别造山带核部罗田片麻岩穹隆内的陈林沟金矿矿石矿物流体包裹体Rb-Sr同位素年代和郭云坳金矿矿体围岩的钾长石K-Ar同位素年代分别为123.0±11 Ma和103.0 Ma,其与区内大规模花岗岩侵位和北大别变质地体快速隆升冷却的年龄和造山带两侧成矿带的成矿时代相吻合,由此证实在大别造山带核部的金属成矿时代也集中于白垩纪,与造山带在造山后伸展构造环境下的隆升阶段相对应.Abstract: Chenlingou and Guoyunao gold deposits are located in the core of Dabieshan orogenic belt.Rb-Sr dating for the fluid indusion from Chenlingou gold deposit reports 123.0±11 Ma;and K-Ar dating for the altered wallrocks of Guoyunao gold deposit is 103.0 Ma;which correspond to the age of granite intrusion in the region and the uplifing of Dabieshan orogenic belt,as well as the metallogenetic epoch of the ore belts on both sides of the orogenic belt.This result confirms that the metallogenetic epoch of deposit in the core of Dabieshan orogenic belt is Cretaceous.The metallogenesis is related to the delamination and de-rooting of Dabieshan orogenic belt.