科研之友
微信
新浪微博
Facebook
分享链接
摘要
The Northeast China region geologically lies to the east of the Central Asian Orogenic Belt (CAOB), where is approximately in the centre of the ancient Siberia Plate, North China Plate and the Pacific Plate. Therefore, it is a critical area for solving the tectonic evolution of the East-Asian continent and has drawn much attention. The Erguna massif and the Xing' an massif are two important tectonic units in the west part of the Northeast China, a 300 km longmagnetotelluric sounding profile of 63 broadband MT sites across the eastern margin of the Erguna massif and the western margin of the Xing' an massif has been completed. Data process and analysis include calculation of the 2D skewness and electric strike of the MT profile, and the nonlinear conjugate gradient (NLCG) 2D inversion is adopted to invert the data with combined TE and TM modes. An electrical structure model of crust and upper mantle was obtained, which can be divided into three tectonic units: the Erguna massif, the collision belt and the Xing' an massif, which is consistent with the regional geology. The research shows that the upper crust of the study area may be igneous rocks representing multi-periodic magmatic activities, the conductive bodies in the middle-lower crust of the Erguna massif and Xing' an massif imply that the crust is non-rigid and may be formed in the post orogenic extensional environment. The Derbugan Fault may be a crustal fault. The conductive bodies in the middle-lower crust of the collision belt connected with the below conductive bodies may indicate the upwelling material channel of the mantle reflecting the rising of the mantle material is an important impetus of the extension, and the formation of the Hailar Basin may be related to the thermal uplifting.
- 出版日期2017-2
- 单位吉林大学; 中国地质科学院; 中国地质大学（北京）
