粤北棉花坑铀矿床方解石地球化学特征及其地质意义

摘要

Analysis of trace elements in calcite before and after mineralization at Mianhuakeng uranium deposit, and contrast with the normal granite, to explore the rich uranium ore forming fluid properties and calcite mineral sources. The research show that: Value of highly compatible elements Cr, Co, Ni in calcite sample contain was similar with alteration rock's and ore bearing granite's, but significantly different with mafic dikes's. In the scatter plot of La/Ho-Y/Ho, calcite samples at different stages in a same horizontal line, showed that the homology of all calcite samples. The rare earth element distribution curve of calcite was quite similar with alteration rock and country rock of granite, but significantly different with diabase's, showed that the metallogenic material of calcite may originate from ore bearing granite, rather than diabase.%通过对棉花坑铀矿床矿前期、成矿期、矿后期方解石的微量元素分析,以及与正常花岗岩微量元素的对比,探讨了富铀矿成矿流体性质及方解石成矿物质来源.研究结果显示:方解石所含的高度相容元素Cr、Co、Ni 含量与蚀变岩石及赋矿花岗岩较为接近而与基性岩脉区别明显.在La/Ho-Y/Ho 图上,不同期次方解石样品基本沿一水平线分布,表明其同源性.方解石与蚀变岩石及花岗岩围岩的稀土元素配分曲线具有较好的相似性,而与辉绿岩的稀土元素配分曲线则截然不同,说明方解石的成矿组分可能主要来源于赋矿花岗岩而不是辉绿岩.