砂岩型铀矿“源-汇”系统  

Source-to-sink system of sandstone uranium mineralization

作　　者：贺锋[1] 张字龙[1] 武正乾 刘鑫扬 刘持恒 李西得[1] HE Feng;ZHANG Zilong;WU Zhengqian;LIU Xinyang;LIU Chiheng;LI Xide(CNNC Key Laboratory of Uranium Resource Exploration and Evaluation Technology Beijing Research Institute of Uranium Geology,Beijing 100029,China;Research Institute No.203,CNNC Xi'an 710086,China;China Nuclear Geology Bureau,Beijing 100013,China)

机构地区：[1]核工业北京地质研究院中核集团铀资源勘查与评价技术重点实验室,北京100029 [2]核工业二〇三研究所,陕西西安710086 [3]中国核工业地质局,北京100013

出　　处：《世界核地质科学》2024年第3期419-433,共15页World Nuclear Geoscience

基　　金：中核集团青年英才项目(编号:地QNYC2301);中核集团集中研发项目(编号:中核科2021-143);中国核工业地质局项目(编号:202201-08、2022-17)联合资助。

摘　　要：把从“源”到“汇”的分析方法应用到我国北方盆地砂岩型铀矿成矿作用研究中来,确定不同时期含铀物质的汇流路径,有利于砂岩型铀矿的富集机理和成矿规律的研究和总结。砂岩型铀矿“源—汇”系统是富铀物质从蚀源区风化剥蚀或从盆地深部富铀烃源岩活化,经汇流体系运移,再到盆地有利赋矿砂体聚集成矿的物理、化学和生物作用的过程,主要包括铀源、汇流体系和富集体系三部分。铀源外源是指在产铀盆地边缘大面积出露的富铀基底和岩石;内源是指含矿目的层本身的含铀建造,是在沉积成岩过程中形成的铀预富集;盆地深部富铀烃源岩在高温-高压条件下排烃,通过活动断裂可为浅部砂岩铀矿提供铀源。富铀物质从铀源区风化或活化搬运迁移到赋矿砂体并在砂体中运移的统一过程称为铀成矿汇流体系,沉积盆地的含铀物质主要在沉积期和成矿期通过汇流体系进入赋矿层位中。铀富集体系是砂岩中还原性物质或微生物等将含铀流体还原沉淀富集成矿的相关整体。鄂尔多斯盆地西南部具有浅部渗入、深部渗出汇流体系特点,渗入与渗出汇流体系的相互叠加改造对铀成矿也起到了比较重要的作用。The application of source to sink analysis method in the study of the formation of sandstone-type uranium deposits in the basins of northern China is conducive to the study and summary of the enrichment mechanism and metallogenic pattern of sandstone-type uranium deposits.The physical,chemical and biological processes of the whole uranium metallogenesis,from denudation of source material to confluence and enrichment,are considered as a complete source-to-sink system of sandstone-type uranium deposits.The source-to-sink system of sandstone uranium deposit is composed of three parts:uranium source,uranium confluence system and uranium mineralization.Uranium sources can be divided into three types:external uranium sources,internal uranium sources and uranium sources in deep basin.The external uranium source refers to the large-scale exposed rich uranium basement and rock at the edge of the uranium producing basin.The internal uranium source refers to the uranium bearing formation of the target layer itself,which is the preconcentration of uranium matter formed in the process of sedimentary diagenesis.The uranium confluence system is the transporting process of the uranium matter from the uranium source area to the sand body and migrating in the ore bearing body.Under the high temperature and pressure of hydrocarbon expulsion,uranium rich source rocks in deep basin can provide uranium sources for shallow sandstone uranium deposits through active faults.The uranium rich matter migrate to the interior of the target layers through the confluence system in the sedimentary and metallogenic periods.The uranium mineralization system is a process of reducing the uranium bearing fluid to precipitation and enrichment by reducing substances or microorganisms in sandstone.Palaeogeomorphology restoration is one of the important methods for the study of source-to-sink system of sandstone-type uranium deposits.The restoration of palaeogeomorphology in sedimentary basins is helpful to determine the distribution characteristics of fa

关 键 词：砂岩型铀矿 “源—汇”系统 铀源 汇流体系 铀富集体系 

分 类 号：P619.14[天文地球—矿床学]