气候变化领域集成服务门户(CCPortal): Lithospheric structure and transformation of the Songnen and Jiamusi blocks in the eastern segment of the Central Asian Orogenic Belt revealed by 3D magnetotelluric inversion

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DOI	10.1016/j.tecto.2021.229015
	Lithospheric structure and transformation of the Songnen and Jiamusi blocks in the eastern segment of the Central Asian Orogenic Belt revealed by 3D magnetotelluric inversion
	Xin Z.; Han J.; Liu C.; Liu L.; Tian Y.; Yang B.; Li Z.; Mu Q.
发表日期	2021
ISSN	00401951
卷号	816
英文摘要	The Central Asian Orogenic Belt (CAOB) is the largest accretionary orogenic belt in the world. The Songnen and Jiamusi blocks, which are located along the eastern segment of the CAOB, form a complex structure influenced by the Mudanjiang ocean closure and the Paleo-Pacific plate subduction. Constraints on the deep structure of the Songnen and Jiamusi blocks are critical for studying the evolution, transformation and current activity of the CAOB. This study presents an analysis and interpretation of a 450-km-long magnetotelluric profile that imaged the deep lithospheric structure of these two blocks. The best-fit three-dimensional resistivity model, based on the nonlinear conjugate gradient algorithm, highlights the key lithospheric structures. The results show that the lithosphere beneath the Lesser Xing'an Range in the Songnen block is characterized by a high-resistivity structure, which is mainly related to the granite formed in multiple stages. The crust forming the Sanjiang basin in the Jiamusi block possesses a high–low–high resistivity structure in the transverse direction, corresponding well to the tectonic units. The low-resistivity structure of the Fujin uplift extends to the mantle, which represents mantle material that intruded the crust. There is a low-resistivity structure beneath the suture zone of the two blocks that is homologous with the large-scale low-resistivity anomaly beneath the basin and is related to the subducted Paleo-Pacific plate. Strong dehydration at the inflection point of the plate reduces the solidus temperature of the mantle material, resulting in melt and upwelling of mantle material. The Jiamusi block can be divided into southern and northern parts, possessing different structures. The southern part represents an original part of either the Gondwana continent or Tarim craton. The Sanjiang basin, in the northern part, has been heavily influenced by the subducted Paleo-Pacific plate, and is a region of strong activity. © 2021 Elsevier B.V.
关键词	Deep resistivity structure Jiamusi block Magnetotelluric sounding Paleo-Pacific plate subduction Songnen block
英文关键词	Magnetotellurics; Nonlinear programming; Three dimensional computer graphics; Central Asian orogenic belt; Complex structure; Different structure; Inflection points; Lithospheric structure; Nonlinear conjugate gradient algorithms; Resistivity modeling; Solidus temperature; Plates (structural components)
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/208093
作者单位	College of Geoexploration Science and Technology, Jilin University, Changchun, 130026, China; Key Laboratory of Applied Geophysics, Changchun, 130026, China
推荐引用方式 GB/T 7714	Xin Z.,Han J.,Liu C.,et al. Lithospheric structure and transformation of the Songnen and Jiamusi blocks in the eastern segment of the Central Asian Orogenic Belt revealed by 3D magnetotelluric inversion[J],2021,816.
APA	Xin Z..,Han J..,Liu C..,Liu L..,Tian Y..,...&Mu Q..(2021).Lithospheric structure and transformation of the Songnen and Jiamusi blocks in the eastern segment of the Central Asian Orogenic Belt revealed by 3D magnetotelluric inversion.Tectonophysics,816.
MLA	Xin Z.,et al."Lithospheric structure and transformation of the Songnen and Jiamusi blocks in the eastern segment of the Central Asian Orogenic Belt revealed by 3D magnetotelluric inversion".Tectonophysics 816(2021).