Deep structure geometry features of Haiyuan Fault and deformation of the crust revealed by deep seismic reflection profiling

作者：Wang Hai-Yan^*; Gao Rui; Yin An; Xiong Xiao-Song; Kuang Chao-Yang; Li Wen-Hui; Huang Wei-Yi

来源：Acta Geophysica Sinica, 2012, 55(12): 3902-3909.

DOI：10.6038/j.issn.0001-5733.2012.12.003

• Deep seismic reflection profile
• Haiyuan fault
• Lithosphere structure
• Geometric shape

Because of the incessant uplifting and pushing of the active Qinghai-Tibet Plateau, a number of structural systems with different trends on the Qinghai-Tibet plateau northeastern margin are formed under the joint action of northeastward pushing, blocking of circumjacent blocks, and the squeezing and deformation in the internal block of the northeastern margin of the plateau. Cenozoic tectonic deformation and seismic activity is intense, several large deep fault zones are distributed in the area. The Haiyuan fault is a left strike-slip fault zone with the strongest activities and the largest scale among the arc and active fault zones of the northeastern margin of Qinghai-Tibet Plateau, which is an important tectonic zone boundary fault and also an active fault controlling earthquake activity. The northern part of the high-resolution deep seismic reflection profile completed by CAGS in 2009 was used in this paper, and the preliminary interpretation revealed the deep geometry of the Haiyuan fault zone and the fine structure of the crust and upper mantle of its both sides. The results showed that the Haiyuan fault is not simply steep or moderate, but its geometric shape changes with depth. The continuous reflection characteristics of the Moho under the Haiyuan fault show that Haiyuan fault is not a trans-crust fault breaking up the Moho directly. The research results provide seismological basis for studying the lithosphere deformation mechanism of the northeastern margin of the Qinghai-Tibet Plateau.

• 出版日期2012-12
• 单位中国地质科学院