Electrical structures of the lithosphere along the Jiamusi massif and its eastern edge
LIU Guo-Xing, ZHANG Xing-Zhou, YANG Bao-Jun, WENG Ai-Hua, TANG Jun-Hui, LI Xue-SenCollege of Geoexploration Science and Technology, Jilin University, Changchun 130026, China
The Jiamusi massive and its eastern edge are important geologic structural unit in the northeast part of China, its structure meaning has drawn extensive attention. To detect the relationship of deep crust construction and structure between Jiamusi massive and its east region, a research of MT detection along the Huanan_Raohe line (about 240km) has been conducted. By adopting two_dimensional smooth model to inverse the MT data of Huanan_Raohe MT profile, the result has distinctly revealed electrical structure of the section: (1) In west segment of the section there is a geosphere which has a stable high resistivity feature and stable thickness about 90km, within the depth of more than ten kilometers exists a high conductivity layer, corresponding to Jiamusi massive, (2)The central part of the section obviously contains a geoelectro gradient zone, which indicates the east boundary of the Jiamusi massive and its deep configuration state, (3)The east segment of the section indicates that the east superficial segment of the Jiamusi massive is thrust nappe, and the several high resistivity bodies in the deep are probably earlier subducted lithosphere relic.