浙江大桥坞铀矿床铅、氢、氧同位素研究

大桥坞矿床是是赣杭火山岩铀成矿带重要的铀矿床之一。通过对大桥坞铀矿床铅、氢和氧同位素及前人资料的综合研究,探讨了矿床成矿流体来源。研究表明,花岗斑岩、凝灰岩、辉绿岩、铀矿石中黄铁矿、蚀变围岩中黄铁矿的Pb同位素组成变化较小,可能指示它们具有具有相似的源区。在铅构造模式图中,铅同位素投影点分布范围较广,但多数集中于地幔和造山带演化线附近,反映了铅的来源与岩浆活动有关。氢、氧同位素组成显示,成矿流体具有大气降水的性质。研究认为,大桥坞铀矿床成矿物质来源具有壳幔源混合特点。

Lead,Hydrogen and Oxygen Isotopic of Daqiaowu Uranium Ore-deposit,Zhejiang Province

Daqiaowu uranium deposit is one of important uranium deposits in the Gan-Hang volcanic-type uranium metallogenic belt.Based on the Lead,Hydrogen and Oxygen Isotopic and previous studies,the sources of ore-forming fluid are discussed.Results show that Pb isotopic compositions of granite porphyry,tuff,diabase,Pyrite in ore and altered rock have a small variation,which indicate their source is similar.The distribution range of lead projection point is wide from the tectonic mode,while most of them are concentrated in mantle and orogenic belt.This indicates that source of lead has some relationship with magmatism.The composition of hydrogen and oxygen isotopic shows that ore-forming fluid has the property of atmospheric precipitation.The results further support that the material source of Daqiaowu uranium deposit has the mixed crust-mantle.