1. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037;
2. Key Laboratory of Earthprobe and Geodynamics, MLR, Beijing 100037;
3. Research Center on Deep Exploration & Deep Exploration Symposium, Chinese Academy of Geological Sciences, Beijing 100037;
4. School of Prospecting & Surveying Engineering,Changchun Institute of Technology, Changchun 130021
Abstract:
Nenjiang fault zone, located in the Middle Northeast China, and the eastern margin of the Great Xing’an Range, is the basin—controlling fault zone of the western margin of the depression of the Songliao Basin. Tectonically, it is the eastern part of the central Asian oceanic belt, and the boundary between the Xing’an and Songnen blocks. The research of it will shed a light on the evolution of the Songliao Basin, the basin—range coupling relation between the Great Xing’an Range and the Songliao Basin, and the nature of the Xing’an and Songnen blocks. In this paper, by the new deep seismic reflection profile, we revealed the geometry features of the Nenjiang fault zone, which is a flower structure. The Nenjiang fault zone is not the detachment zone in the Inner Songliao Basin, but an ultra—crustal fault. It controls the east—moving of the crustal materials of the Great Xing’an Range and the depression of the Songliao Basin in Mesozoic. The present Nenjiang fault zone is not the successor of the collision zone between Xing’an and Songliao blocks in Late Paleozoic. Moho may act as a decollment surface to induce the east—slipping of the mantle subduction zone.
Xiong Xiaosong,Gao Rui,Hou Hesheng et al. Deep structure geometry features of Nenjiang fault zone and crustal deformation revealed by deep seismic reflection profile[J]. Chinese Journal of Geology, 2016, 51(3): 694-705.