CSAMT在赛汉塔拉凹陷赛汉组砂体识别中的应用研究

Application of CSAMT in sand body identification of Saihan Formation in Saihantala Sag

中文关键词: CSAMT  铀矿勘查  模型正反演  砂体空间展布特征  赛汉塔拉凹陷中图分类号:P619.14文献标志码:A文章编号:1674-7801(2025)02-0327-10

英文关键词: CSAMT  uranium exploration  model forward and inversion  spatial distribution characteristics ofsand body  saihantala Sag

中文摘要:

      二连盆地腾格尔坳陷西部具有良好找矿远景，已发现的铀矿化赋存在下白垩统赛汉组砂体中，因此在赛汉塔拉凹陷开展了可控源音频大地电磁测量(CSAMT)。本文通过模型的正反演计算，选择初始模型为二维原始数据滑动平均模型、第一层厚度为 40 m、圆滑系数为 0.50来对原始数据进行反演处理，认为研究区下白垩统赛汉组共发育 3片大规模砂体，砂体埋深及厚度由南向北逐渐增大，其最小埋深约 20 m，最大埋深 320 m，最大厚度为 380 m，最小厚度为 20 m。上述砂体整体上呈条状分布，整体较连续、稳定且规模较大，砂体物源主要来自于南部的温都尔庙隆起。通过钻孔对比及后期验证，可以看出 CSAMT在该地区地层分层、砂体探测方面应用效果良好，为下一步铀矿勘查工作提供有效依据。

英文摘要:

      The western part of Tengger Depression in Erlian Basin has a good prospecting prospect. The discov-ered uranium mineralization occurs in the sand body of the Lower Cretaceous Saihan Formation. Therefore, thetrolled source audio magnetotelluric survey (CSAMT) was carried out in the Saihantala Sag. In this paper, through.forward and inversion calculation of the model, the initial model is selected as the two-dimensional original datamoving average model, the thickness of the first layer is 40 m, and the smoothness coefficient is 0.50 to invert theoriginal data. It is considered that three large-scale sand bodies are developed in the Lower Cretaceous Saihan For-mation in the study area. The buried depth and thickness of the sand bodies gradually increase from south to north.The minimum buried depth is about 20 m, the maximum buried depth is 320 m, the minimum thickness is 380 m,and the minimum thickness is 20 m. The above-mentioned sand bodies are distributed in strips on the whole, whichare continuous, stable and large-scale on the whole. The source of sand bodies mainly comes from the Wenduer-miao uplift in the south. In stratigraphic stratification and sand body detection in this area, which provides an effec-tive basis for the next step of uranium exploration.