断层的地电响应特征及其在砂岩型铀矿地质解译中的作用——以巴楚隆起地区为例  

Electrical Response of Fault and Its Impact in Sandstone Uranium Exploration:A Case Study of Bachu Uplift

作　　者：王恒 程纪星[1] 胡英才[1] 陈闫[2] 陈汉波[3] 张濡亮[1] WANG Heng;CHENG Jixing;HU Yingcai;CHEN Yan;CHEN Hanbo;ZHANG Ruliang(Beijing Research Institute of Uranium Geology,Beijing 100029,China;College of Exploration Science and Technology,Jilin University,Changchun,Jilin 130061,China;College of Earth Sciences,Guilin University of Technology,Guilin,Guangxi 541006,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]吉林大学地球探测科学与技术学院,吉林长春130061 [3]桂林理工大学地球科学学院,广西桂林541006

出　　处：《铀矿地质》2024年第4期765-772,共8页Uranium Geology

基　　金：核能开发项目(编号:物HTLM2101-04)资助。

摘　　要：砂岩型铀矿成矿理论认为,适宜的构造斜坡带可发展为有利的铀成矿区。斜坡带内受重力、挤压等因素形成的断裂对铀成矿和保矿都有非常重要的作用。北方沉积盆地内,利用大地电磁法进行断裂解译的精度不仅受沉积地层绝对电阻率的影响,也受地层间相对电阻率影响。为准确解译隐伏断裂,建立了不同电性差异下的正、逆断层地电模型,正反演模拟了不同电阻率差异及不同性质断层模型的一维、二维反演电阻率断面。正反演模拟结果表明:正、逆断层在反演地电断面上具有不同的特征,即正断层在断层斜面处呈倾斜形态,而逆断层在断层斜面处呈凹陷形态;一维反演结果对断裂的识别效果要优于二维反演结果。通过断层地电相应特征规律的总结,为巴楚隆起西部凹陷大地电磁剖面隐伏断裂的解译提供了依据与指导。According to the theory of sandstone type uranium mineralization,the suitable structural slope is favorable for uranium metallization.The faults formed by gravity and extrusion in the slope zone play an important role in uranium mineralization and ore preservation.In sedimentary basins,the accuracy of fault interpretation by magnetotelluric method is affected not only by the absolute resistivity,but also the resistivity difference between strata.In order to accurately interpret the potential faults,the geoelectric models of normal and overthrust fault under different electrical differences were established,and the 1D and 2D inverse resistivity cross sections of the fault models with different resistivity differences and different properties were simulated.The simulated results showed that the normal and overthrust fault have different characteristics in the geoelectric inversion section,the normal faults are inclined at the slope of the fault plane,while the overthrust faults are concave in fault plane.The effect of 1D inversion is better than that of 2D inversion.The summarized corresponding characteristics of fault provided the basis and guidance for fault interpretation of magnetotelluric profile in the western depression of Bachu uplift.

关 键 词：巴楚隆起 断层模拟 电磁测深 地电断面 

分 类 号：P631[天文地球—地质矿产勘探]