柴达木盆地北缘油气与砂岩型铀矿化关系研究  

Relationship between Oil-gas and Sandstone-type Uranium Mineralization in the Northern Margin of Qaidam Basin

作　　者：王继斌 廉康 陈擎 王刚 WANG Jibin;LIAN Kang;CHEN Qing;WANG Gang(No.203 Research Institute of Nuclear Industry,Xi’an 710086,China)

机构地区：[1]核工业二〇三研究所,陕西西安710086

出　　处：《东华理工大学学报（自然科学版）》2023年第5期510-517,共8页Journal of East China University of Technology(Natural Science)

基　　金：中央财政铀矿战略选区项目(202105);中央财政铀矿调查评价项目(202218)。

摘　　要：柴达木盆地北缘油气资源丰富,近年来发现了较多与油气有关的砂岩型铀矿化线索,初步评价具有较好的铀成矿潜力。基于区内铀源、铀储层、构造及水动力体系等铀成矿地质条件的分析,结合柴北缘油气分布和运聚、放射性异常分布特征,对铀矿化与构造、油气的时空关系进行解析,提出构造作为中间媒介,将具有还原性质的油气与层间含铀含氧水在时间和空间上联系起来,形成动态化、系统化的砂岩型铀成矿体系。深部油气沿断裂、节理等构造向浅部地层近垂向耗散运移并在背斜构造中汇聚成藏,斜切背斜的断裂使背斜靠近断裂的一端抬升,形成构造高差,促进层间含铀含氧水向断裂运移排泄,油气和含氧水在断裂附近交汇,形成氧化还原过渡带,驱使高价铀还原富集,并在被断裂切错的背斜构造附近成矿。综合分析认为,柴北缘新生代铀矿化受断裂和褶皱构造联合控制作用明显,发育断裂构造的背斜油气藏附近是砂岩型铀成矿的有利部位。The northern margin of Qaidam basin is rich in oil and gas resources.In recent years,sandstone-type uranium mineralization clues related to oil and gas have been found,showing good uranium mineralization potential.Based on the inductive analysis of uranium metallogenic geological conditions such as uranium source,uranium reservoir,structure and hydrodynamic system in the area,and combined with the characteristics of oil and gas distribution,migration and accumulation,and radioactive anomaly distribution in the northern margin of Qaidam basin,the spatial and temporal relationship between uranium mineralization and structure,oil and gas is analyzed.It is proposed that the structure is used as an intermediate medium to link the reducible oil-gas with the oxygenated water containing uranium in time and space,forming a dynamic and systematic sandstone-type uranium metallogenic system.Deep oil and gas migrate vertically along faults,joints and other structures to shallow strata and accumulate in anticline structures.The fault of the oblique cutting anticline uplifts one end of the anticline near the fault to form a structural height difference,which promotes the migration and excretion of interlayer uranium and oxygen-containing water to the fault.The intersection of oil-gas and oxygen-containing water near the fault forms a redox transition zone,which drives the reduction and enrichment of high-valence uranium and mineralization near the anticline structure that cut by the fault.Comprehensive analysis shows that the Cenozoic uranium mineralization in the northern margin of Qaidam basin is obviously controlled by the combination of faults and fold structures,and the anticline reservoirs with fault structures are favorable sites for sandstone-type uranium mineralization.

关 键 词：砂岩型铀矿 油气 断裂构造 柴达木盆地北缘 

分 类 号：P619.14[天文地球—矿床学]