Characteristics and Tectonic Implications of Lithospheric Density Structures beneath Western Junggar and Its Surroundings
Xu Shunfang
Chen Chao
Du Jinsong
Sun Shida
Hu Zhengwang
Abstract：Structures in the crust and uppermost mantle beneath western Junggar and its surroundings,the key to better under-standing of the tectonic evolution of the Junggar basin,are studied in this paper.Firstly,the Bouguer gravity anomaly is calcu-lated from the satellite gravitational field model.Then 3D inversion technique is utilized,and the density imaging is operated in the crust and uppermost mantle beneath the western Junggar and its surroundings and finally the anomalous density structure at the depth range of 0-80 km is obtained.Crustal density distribution in the ancient oceanic crust of the Junggar indicates the possible subductions under the Siberian plate northeastwardly and the western Junggar northwestwardly.Density distribution in the uppermost mantle suggests that the relatively low density beneath Altay fold belt may have resulted from the thick sialic layer of the ancient continent,and Kazakhstan plate & Junggar basin are dominated by a relatively whole high-density structure while the significant density changes beneath the Tianshan fold belt describe the ultra-crustal deep faults and also the nicks of the tectonic activities and the lithospheric deformations.
Keywords：western Junggarsatellite gravityBouguer gravity anomalydensity imaginglithospheric density structuretectonicsgeophysics
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 1556-1565 )