固体地球物理研究生学术报告第二期(2)

We present a magnetotelluric study of the hot dry rock (HDR) geothermal resources beneath the Guide Basin, Northeast Tibetan Plateau. Data acquired from 92 broadband magnetotelluric sites was used to construct a 3D resistivity model of the geothermal system. The 3D inversion shows that the resistivity has a large lateral variation in the shallow zone (<1km) generally characterized by high resistivity under the Zhacang geothermal field, while the Sanhe Plain heat field is mainly characterized by low resistivity. With the increase of depth, the lower part of Sanhe Plain also shows high resistivity. In the range of 10km~20km, both the Zhacang thermal field and Sanhe plain thermal field show low resistivity feature. Based on the 3-D electrical model, combining with GPS, drill core data, the geodynamic model is proposed to interpret the thermal structure and geothermal genesis mechanism in Guide basin, and provide additional insight into the geothermal processes in the northeastern Tibetan Plateau.