世界核地质科学2025，Vol.42Issue(4)：739-751,13.DOI:10.3969/j.issn.1672-0636.2025.04.005
塔里木盆地塔河地区奥陶纪富铀层系空间分布及富集机理
The spatial distribution and enrichment mechanism of Ordovician uranium-enriched strata in Tahe area,Tarim basin
摘要
Abstract
Tarim basin is a large superimposed sedimentary basin that has undergone multiple tectonic cycles.Multiple energy resources,including oil,natural gas,coal,and uranium,coexist within the same basin,exhibiting vertical superposition and close genetic relationships.Recent exploration has revealed widespread uranium enrichment within the deep Ordovician strata;however,its distribution patterns lack systematic study,and its genetic mechanisms remain controversial.This study comprehensively utilized well logging,seismic data,and core samples to identify and characterize uranium-enriched intervals.Lithofacies hosting uranium enrichment were determined through petrographic analysis and XRF micro-area scanning of typical outcrops and core samples from well locations.The spatial distribution patterns and host positions were revealed based on statistical analysis of drilling data.The results indicate that uranium enrichment is the primary factor controlling the radioactive anomalies within Ordovician strata in Tahe area.High-uranium intervals are predominantly developed at the base of Upper Ordovician Qerbake formation,exhibiting strong stratabound characteristics,regional stability,and facies-controlled differentiation.Integrated petrological and geochemical analyses reveal that the primary uranium-hosting lithofacies is marlstone within the condensed section.Characteristic associated minerals include pyrite,phosphates,and glauconite.Integrating mechanisms of uranium migration/precipitation,Ordovician sedimentary evolution,and secondary hydrocarbon adsorption,a sedimentary-diagenetic-structural tripartite synergistic uranium enrichment model was proposed:1)anoxic,stagnant conditions during rapid transgression,coupled with uranium adsorption driven by organic matter via upwelling currents provided the foundation for the enrichment;2)an acidic,reducing environment generated during early diagenesis promoted uranium precipitation;3)fault systems facilitated migration,and reduction/adsorption by hydrocarbon fluids further enhanced localized uranium enrichment.This interval serves as a marker bed for Middle-Upper Ordovician sequence boundary,indicating paleo-ocean redox conditions and tracing hydrocarbon migration pathways.关键词
γ能谱测井/富铀层系/成因机理/塔河油田Key words
radioactive logging technology/uranium-enriched strata/genesis mechanism/Tahe oilfield分类
天文与地球科学引用本文复制引用
刘昊成,林承焰,董春梅,任丽华,鲁新便..塔里木盆地塔河地区奥陶纪富铀层系空间分布及富集机理[J].世界核地质科学,2025,42(4):739-751,13.基金项目
"十三五"国家科技重大专项(编号:2017ZX05009001)资助 Supported by National Natural Science Foundation of China(No.2017ZX05009001) （编号:2017ZX05009001）
