Geoelectrical Evidence for Characteristics of Lithospheric Structure Beneath the Yuejinshan Collage Zone and Its Vicinity in Northeast Asia

Abstract

AbstractTo make a thorough investigation of the contact relations among northeast Asian Wandashan terrane and its both sides Jiamusi massif and Xingkai massif, and its control functions of the oil‐gas conditions to Yuejinshan collage zone field deposit basin, we have deployed 5 MT sounding profiles with. A total length of 1104 km. The survey results are as follows: (1) The major characteristic of geoelectricity structure in the study area is that the stable high resistivity core of the Jiamusi massif gets thinner from the middle part to south and north directions, the Xingkai massif of high resistivity is deepening and thickening from east to west and the south of Wandashan terrane has much more high resistivity bodies gradually decreasing to the north. (2) The southwest part of the Wandashan terrane shows “ox horn” shape and separates the Jiamusi massif and Xingkai massif apart. Compared with the original joint positions of the Wandashan terrane and Jiamusi massif in the Tongjiang‐Baoqing‐Dangbi belt, the new positions move to the south from Baoqing to the Mashan‐Hualin belt. (3) There are two possible causes for structure formation in the Wandashan terrane, one is emergence by subduction, and the other is thermal upwelling of asthenospheric materials. Maybe the edge of the high resistivity core which exists in the Jiamusi massif is the eastern boundary of the massif. (4) In the 4 basins, except the Boli basin, high resistivity bodies of small scales and many high‐conductivity zones are present in the basements, which are favorable for the generation setting of hydrocarbon.