CSAMT方法在腾格尔坳陷西缘下白垩统赛汉组砂体识别中的应用  

Application of CSAMT Method in Sand Body Identification of Lower Cretaceous Saihan Formation in the Western Margin of Tengger Depression

作　　者：张伟[1,2,3] 李英宾 张俊伟 张占彬[1,2,3] 魏滨 李毅 ZHANG Wei;LI Yingbin;ZHANG Junwei;ZHANG Zhanbin;WEI Bin;LI Yi(Airborne Survey and Remote Sensing Center of Nuclear Industry,Shijiazhuang,Hebei 050002,China;CNNC Key Laboratory of Uranium Resources Geophysical Exploration Technology,Shijiazhuang,Hebei 050002,China;Hebei Provincial Key Laboratory of airborne detection and remote sensing technology,Shijiazhuang,Hebei 050002,China)

机构地区：[1]核工业航测遥感中心,河北石家庄050002 [2]中核集团铀资源地球物理勘查技术中心(重点实验室),河北石家庄050002 [3]河北省航空探测与遥感技术重点实验室,河北石家庄050002

出　　处：《铀矿地质》2021年第6期1112-1120,共9页Uranium Geology

基　　金：中国核工业地质局基金项目“内蒙古二连盆地腾格尔坳陷可控源音频大地电磁测量”(编号:201901-8)资助。

摘　　要：为查明腾格尔坳陷西缘找矿目的层下白垩统赛汉组砂体的发育特征,在布图莫吉凹陷进行了可控源音频大地电磁(CSAMT)测量,通过对测量数据进行正反演处理,获得了该地区沉积盖层的电性结构特征,综合岩石电阻率参数及地质、钻孔等资料解译分析,认为研究区下白垩统赛汉组发育两片大规模砂体,其中查干诺尔凸起东部斜坡带砂体粒度由西向东逐渐变小,越靠近蚀源区砂体粒度越大,反演电阻率值也越高。砂体埋深及厚度由南西向北东逐渐增大,最小厚度约40 m,最大厚度达240 m;布图莫吉凹陷分布的砂体比查干诺尔凸起东部斜坡带砂体粒度要小,其埋深与厚度自南西向北东起伏变化,最小厚度约30 m,最大厚度达340 m。上述砂体呈蛇曲状分布,成因为河流相,整体上较连续、稳定且规模较大,反映该地层发育河流相沉积体系,为后续钻探工程的布设提供了参考。In order to find out the development characteristics of sand bodies in the lower Cretaceous Saihan Formation in the western margin of Tengger depression,controlled source audio frequency magnetotelluric survey(CSAMT)was conducted in Butumoji sag.With the forward and inverse processing of the measured data,the electrical structure characteristics of sedimentary cover rocks in the study area were obtained.Based on the characteristics of rock resistivity parameters,geological and drilling data analysis,it was considered that two large-scale sand bodies were developed in the Saihan Formation of Lower Cretaceous in the study area.The granularity of sand body in Butumoji sag is smaller than that in the eastern slope of Chagannuoer uplift,and its buried depth and thickness fluctuate from southwest to northeast,with a minimum thickness of about 40 m and a maximum thickness of 240 m.The sand bodies distributed in Butumoji sag are finer than those in the eastern slope zone of Chagannuoer uplift,and their buried depth and thickness change from southwest to northeast,with a minimum thickness of about 30 m,the maximum thickness is 340 m.The above-mentioned sand bodies are the product of meander river,which was continuous,stable and large-scale,and provides a reference for the layout of drilling engineering.

关 键 词：CSAMT 砂体发育特征 下白垩统赛汉组 腾格尔坳陷西缘 

分 类 号：P631.325[天文地球—地质矿产勘探] P619.14[天文地球—地质学]