天姆尖破火山机构——潜在的富大铀矿找矿远景区  

Tianmujian caldera——a potential area for locating rich and large uranuim deposit

作　　者：林子瑜 徐金山 陈名佐 蒋金元 范洪海 程崎 

机构地区：[1]中国核工业地质局270研究所,江西南昌330200

出　　处：《铀矿地质》2001年第2期76-82,共7页Uranium Geology

摘　　要：本文通过对天姆尖地区地质、遥感、重磁、地化等资料的综合分析和野外地质调查 ,初步查明了天姆尖破火山机构的成生及展布特征 ,识别出该区大面积分布的碎斑熔岩体系。认为该火山盆地经历了热隆起和破火山机构形成两个演化阶段 ,该区存在大型隐伏富铀花岗岩体 ;区内岩浆在垂向演化过程中 ,铀表现为下部富集而上部贫化带出的特点 ,大量成矿物质随岩浆热液向上进入破火山机构中成矿。此外 ,查明了该区以北东向断裂为主导的北东 北西向菱格状基底构造格局 ,强调了基底断裂对本区岩浆活动、火山盆地形成和铀成矿的控制作用。在对天姆尖地区铀成矿地质条件进行综合分析的基础上 ,指出该破火山机构具有形成富大铀矿床所必备的“源、运、聚、保”等各项条件和有利的多元成矿信息显示 ,是寻找富大铀矿床极为有利的远景区。Based on the comprehensive analysis on geologic, remote sensing, gravimetric, magnetic and geochemical data, and the field geologic investigation, this paper has preliminarily ascertained the formation and the distribution characteristics of the Tianmujian caldera, and recognized the porphyroclastic lava system which is extensively distributed in the area. The authors suggest that the Tianmujian volcanic basin experienced two evolution stages——the thermal uplifting and the formation of caldera, that large concealed uranium-rich granitic massif occurs in the area, and during the vertical evolution process the uranium showed its concentration in the lower part and depletion in the upper part, and large amount of ore-forming material moved upward along with the magmatic hydrothermals entering the caldera to form uranium deposit. In addition, it is clarified that the NE-NW rombic-formed basement structural pattern is predominated by the NE-trending fault. At the same time, the important role of the basement faults in controlling the magmatic activities, in the formation of volcanic basins, as well as the formation of uranium mineralization is emphasized. On the basis of the above comprehensive analysis the authors suggest that the Tianmujian caldera is a quite favourable potential area for possessing the basic conditions necessary for the formation of rich and large uranium deposit including uranium“source, migration, concentration, preservation” and favourable multiple metallogenic information is displayed in the Tianmujian area.

关 键 词：破火山机构 铀矿床 找矿远景 成矿地质 控矿作用 

分 类 号：P619.140.8[天文地球—矿床学]