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苏鲁造山带及毗邻华北地块,是中国东部地学研究的热点区域,研究其深部结构可以为讨论苏鲁超高压变质带以及华北克拉通演化提供重要的证据.对横切苏鲁造山带获得的一条大地电磁测深剖面资料进行了解释,剖面沿SE129°,西起华北地块,跨郯庐断裂带、苏鲁超高压变质带、苏鲁高压变质带,止于扬子地块.大地电磁反演解释采用了二维非线性共扼梯度法,用TE和TM联合模式得到了关于测区地下150km以上的电性剖面.该电性剖面在横向上,沿剖面自西而东,划分出了7个电性分区,电性边界带与郯庐断裂带、海州-泗阳断裂以及嘉山-响水断裂等重要的边界断裂具有很好的对应关系;纵向上,划分出6个电性构造单元.发现了在华北地块与扬子地块内存在着(壳内的)高导区,而苏鲁造山带下部没有发现高导区,这一点与大别造山带存在较大的差异.发现了在50~90km之间层位,存在较连续的相对低阻带,推测为上地幔顶部的软弱带,在该低阻带下部分别对应华北地块上地幔浅部相对高阻区、苏鲁造山带上地幔浅部相对低阻区以及扬子地块上地幔浅部相对高阻区.从整个二维电性结构模型来看,在苏鲁造山带及邻区上地幔浅部不存在异常低的电阻率,这表明现今已不存在与岩石圈减薄有关的热软流圈物质.
The Sulu orogenic belts and the adjacent North China block are the hot spots in the geo-geosciences research in eastern China, and studying the deep structure can provide important evidence for discussing the Sulu UHP metamorphic belt and the evolution of the North China Craton. The data of the earth’s electromagnetic sounding profile are explained along the section of SE129 °, the North China block in the west, the Tan-Lu fault zone, the Sulu UHP metamorphic belt and the Sulu high-pressure metamorphic belt and the Yangtze block. A two-dimensional non-linear conjugate gradient method was proposed, and the TE and TM joint model was used to obtain the electrical profile about 150 km above the ground in the survey area. The electrical profile was divided into seven sections from west to east along the section There is a good correspondence between the sextric and electrical boundary zones and the important boundary faults such as the Tan-Lu fault zone, the Haizhou-Siyang fault and the Jiashan-Xiangshui fault. In the longitudinal direction, 6 electrical structural units are found. There is a high (in-shell) high-conductivity zone in the North China block and the Yangtze block, but no high-conductivity zone is found in the lower part of the Sulu orogenic belt, which is quite different from that in the Dabie orogenic belt. ~ 90km between the horizon, there is more The continuous relatively low resistivity zone is presumed to be the weak zone at the top of the upper mantle. Corresponding to the relatively high resistivity zone of the upper mantle in the North China block, the relatively low resistivity zone of the shallow mantle in the Sulu orogenic belt, From the two-dimensional electrical structure model, there is no exceptionally low resistivity in the shallow mantle in the Sulu orogen and its adjacent area, indicating that there is no such relationship between rock mass and rock Thinning related to the hot asthenosphere material.