松辽盆地地浸砂岩型铀矿勘查及其找矿方向

20世纪90年代开始,在松辽盆地开展了地浸砂岩型铀矿区域评价工作.盆地的西南部投入数万米钻探工作量开展以第三系和上白垩统嫩江组、姚家组为目的层的找矿工作,取得了较大突破,发现并提交了我国第一个板状砂岩型铀矿床,所建立的双混合叠造铀成矿模式丰富了地浸砂岩型铀成矿理论.在此基础上总结出白垩系砂岩型铀成矿控矿因素和找矿标志.盆地东部构造反转有利于形成砂岩型铀矿床.第三系以潜水氧化为主,还原物质缺乏,而且新构造运动对其改造微弱,总的成矿条件不理想,不宜作为主攻目的层.盆地坳陷阶段沉积的泉头组、青山口组、姚家组为主要找矿目的层,找矿重点在盆地东南部通辽-双辽-德惠地区.下一步科研工作重点为:完善QJD砂岩型铀矿模式、盆地油气与铀成矿关系、白垩纪古水文地质条件的研究.

EXPLORING DEGREE AND PROSPECTING GUIDE TO IN-SITU LEACHING SANDSTONE URANIUM DEPOSIT IN SONGLIAO BASIN

Since 1990 a large amount of regional evaluation work for exploring in-situ leaching sandstone uranium deposit has been done in Songliao Basin and hundreds of thousands of total footage drilled inYaojia Formation, Nenjiang Formation of Upper Cretaceous Series, and the first medium-sized lathlike sandstone uranium deposit in our country has been found. Metallogenic control factors are summarized, exploration criteria for the sandstone uranium deposit in Cretaceous System set up. The double-mixed superposed-transformation metallogeneic model of Qianjiadian deposit enriches the ore-forming theory of in such leaching uranium deposit. Structure inversion can contribute to formation of the sandstone uranium deposit in Southeast Songliao Basin. Tertiary rock can not be main target layer for uranium exploration because of epigenetic phreatic oxidation, low organic matter content, weak transformation of neotectonic movement. Quantou Formation,Qingshankou Formation, Yaojia Formation which deposited in depression period of Songliao Basin are the main target layers, The prospective areas are in Tongliao-Shuangliao-Dehui area in Southeastern Songliao Basin. The next research is to consummate metallogenic model of QianJiadian uranium deposit, reveal relationship between gas-oil and uranium mineralization and study sandstone paleo-hydrogeological conditions of upper Cretaceous Series.