济源-开封坳陷西南部电性结构研究及地热资源远景区预测

应用大地电磁测深(MT)法对济源-开封坳陷西南部深部地层结构和隐伏断裂进行探测研究,共布设了4条MT剖面,获得了84个测深点。通过对大地电磁测深数据的处理、分析和反演,获得了研究区内6 km以浅的二维地电结构模型。结合以往地震和区域地质资料,地层由上至下依次划分为第四系-新近系、古近系、三叠系、二叠系-石炭系、下古生界-元古界。推断了老鸦陈断裂F1与推断断裂F2的位置、产状,其中F1断裂西侧缺失古近系沉积,二者可能对新生代地层沉积厚度有明显的控制作用。认为研究区内有利热储层位应为新近系馆陶组及断裂交汇处附近的三叠系地层。

Electrical structure and forecast of geothermal prospective areas in southwest of the Jiyuan-Kaifeng depression

The magnetotelluric sounding (MT) method was used to detect the deep structure and hidden faults in the southwest of the Jiyuan-Kaifeng depression. Four MT profiles with 84 sounding sites were deployed. Through processing, analysis and two-dimensional inversion of the MT data, a two-dimensional geoelectrical structure model above the depth 6km beneath the study area was constructed. Combining with previous seismic and regional geological data, the strata are divided into Quaternary- Neogene, Paleogene, Triassic, Permian-Carboniferous and Lower Paleozoic-Proterozoic from top to bottom. The location and occurrence of the Laoyachen fault F1 and inferred fault F2 are deduced. Of them, Paleogene sediments lacks on the west side of the F1 fault. Both the faults may have a significant control on the Cenozoic sediment thickness. It is considered that the favorable thermal reservoirs in the study area should be in the Neogene Guantao Formation and Triassic strata near the fault junction.