含煤盆地砂岩型铀矿勘查中的地球物理方法——以二连盆地中东部为例  

Exploring sandstone-hosted uranium deposits in coal-bearing basins using geophysical methods:A case study of the east-central Erlian Basin

作　　者：梁建刚 匡海阳 曹占宁 杨为民[6] LIANG Jiangang;KUANG Haiyang;CAO Zhanning;YANG Weimin(Hohhot General Survey of Natural Resources Center,China Geological Survey,Hohhot 010090,China;Innovation Base for Gold Exploration Technology in the Northern Margin of North China Craton,Hohhot 010013,China;Tianjin Center,China Geological Survey(North China Center for Geoscience Innovation),Tianjin 300170,China;Key Laboratory of Uranium Geology,China Geological Survey,Tianjin 300170,China;Chinese Academy of Geological Sciences,Beijing 100037,China;Shanxi Geophysics and Geochemical Prospecting Institute,Yuncheng 044004,China)

机构地区：[1]中国地质调查局呼和浩特自然资源综合调查中心,内蒙古呼和浩特010090 [2]华北克拉通北缘金矿勘查技术创新基地,内蒙古呼和浩特,010013 [3]中国地质调查局天津地质调查中心(华北地质科技创新中心),天津300170 [4]中国地质调查局铀矿地质重点实验室,天津300170 [5]中国地质科学院,北京100037 [6]山西省地球物理化学勘查院,山西运城044004

出　　处：《煤田地质与勘探》2025年第3期208-219,共12页Coal Geology & Exploration

基　　金：中国地质调查局项目(DD20190121-07,DD20211549)。

摘　　要：【背景】砂岩型铀矿是我国铀资源增长的关键类型,广泛分布于陆相及海陆交互相沉积岩中。当前,我国对其勘查研究多集中于北方中新生代沉积盆地。【目的和方法】二连盆地具有“铀−煤−油”共生特点,以盆地中东部为研究对象,综合运用区域重力、航磁、航空放射性测量等资料,同时布设6条共130 km二维地震剖面,并采用土壤瞬时测氡法,剖析砂岩型铀矿关键控矿要素的地质特征与地球物理响应,构建找矿预测模型,旨在为含煤区找矿提供技术支撑。【结果】研究发现,重力反演揭示了基底隆−坳结构与铀矿富集的关系,航磁、航放明确了蚀源区及铀元素的迁移特征。区域重磁与航放数据识别出苏尼特隆起和巴音宝力格隆起两大蚀源区,揭示了物源供给边界;二维地震圈定了含铀砂体和蚀源区构造“天窗”;氡气测量异常经钻探验证,在马尼特坳陷南部圈定了一条长约20 km、宽1~3 km新的铀成矿带。【结论】区域重磁与航放数据为宏观成矿背景分析提供了重要依据,二维地震与氡气测量在含铀砂体定位及矿化异常识别中优势显著。综合运用多种地球物理方法,实现了多尺度地球物理方法融合,为含煤盆地砂岩型铀矿找矿突破奠定了坚实基础。[Background]Sandstone-hosted uranium deposits,critical to the uranium resources growth in China,are extensively distributed in continental and marine-continental transitional sedimentary rocks.Currently,the exploration and research on these deposits in China focus primarily on the Meso-Cenozoic sedimentary basins in the northern regions.[Objective and Methods]The Erlian Basin exhibits the coexistence of uranium,coals,and oil.This study investigated the east-central part of this basin using multiple geophysical data,including regional gravity survey,aeromagnetic survey,and airborne radioactivity survey(ARS).Furthermore,six 2D seismic profiles totaling 130 km in length were deployed,and instantaneous soil radon measurement as employed.Accordingly,this study analyzed the geological characteristics and geophysical responses of key ore-controlling factors of sandstone-hosted uranium deposits in the region and constructed a prospecting prediction model,aiming to provide technical support for uranium exploration in coal-bearing regions.[Results]Gravity inversion revealed the relationships of the uplift and depression structures in the basement with uranium enrichment,while aeromagnetic survey and ARS determined denudation-related provenance areas and uranium migration patterns.Specifically,the Sonid and Bayinbaolige uplifts were identified as two major provenance areas using regional gravity,magnetic,and aeroradiometric data,with the material supply boundaries delineated.Besides,uranium-bearing sand bodies and the structural skylights of denudation-related provenance areas were delineated using 2D seismic profiling.Through validation of radon anomalies by drilling,this study delineated a new uranium metallogenic belt measuring about 20 km in length and 1‒3 km in width in the southern Manite Depression.[Conclusions]Regional gravity,magnetic and aeroradiometric data provide an important basis for the analysis of the macroscopic metallogenic setting,while 2D seismic survey and radon measurement excel in the localization

关 键 词：砂岩型铀矿 含煤盆地 地球物理方法 二连盆地中东部 

分 类 号：P619.14[天文地球—矿床学]