caa a22 4500 445301058 CHVBK 20180317142557.0 cr unu---uuuuu 170323e20100201xx s 000 0 eng 10.1007/s11430-009-0166-0 doi (NATIONALLICENCE)springer-10.1007/s11430-009-0166-0 Deep seismic sounding data reveal the crustal structures beneath Zoigê basin and its surrounding folded orogenic belts [Elektronische Daten] [ShiXu Jia, XianKang Zhang, JinRen Zhao, FuYun Wang, ChengKe Zhang, ZhaoFan Xu, JiShun Pan, Zhi Liu, SuZhen Pan, GuoWei Sun] Songpan-Garze massif is located at the turning position of tectonics from the near west-east direction to the near north-south direction in the northeastern margin of Qinghai-Tibet Plateau, with Zoigê basin in the centre of the massif. In this paper, we build a crustal structure model of Zoigê basin and its surrounding folded orogenic belts using the deep seismic sounding data in this region. We also discuss structures and properties of the basement in Zoigê basin, tectonic relations between Zoigê upland basin and its surrounding folded orogenic belts, crustal deformation and thickening in the northeastern margin of Tibetan Plateau, and decoupling and relaxing processes in the crust. The results indicate that a special "Mesozoic basement” is formed of Triassic rocks with high density (2.65-2.75 g/cm3) and high velocity (5.6 km/s) in Zoigê basin. Songpan-Garze tectonic massif was transformed into two types of tectonic units with different crustal structures, i.e., relatively stable Zoigê upland basin and active folded orogenic belts around the basin, in the course of the crustal material of Tibetan Plateau flowing eastward and obstructed by surrounding stable blocks. The thickening of the crust in the northeastern margin of Tibetan Plateau mainly occurred in the mid and lower crust, and the structure characterized by low velocities and multiple reflectors obviously appears in the folded orogenic belts around Zoigê basin. It implies that the mid and lower crust underwent a strong tectonic deformation in the folded orogenic areas. The thickness of the crust is about 50 km in Zoigê basin and the folded orogenic belts at the both southern and northern sides of Zoigê basin. The "Mountain root” cannot be identified. It is inferred that during the later orogenic period the eastwards flowing deep materials moved clockwise along the relatively relaxing southern side around the eastern tectonic knot under the obstructing of surrounding rigid massifs, and it resulted in the strong stretching action of the folded orogenic belts around Zoigê basin. Science in China Press and Springer Berlin Heidelberg, 2010 Zoigê basin nationallicence folded orogenic belt nationallicence deep seismic sounding nationallicence basement structure nationallicence crustal structure and tectonics nationallicence Jia ShiXu Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Zhang XianKang Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Zhao JinRen Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Wang FuYun Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Zhang ChengKe Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Xu ZhaoFan Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Pan JiShun Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Liu Zhi Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Pan SuZhen Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Sun GuoWei Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut Science China Earth Sciences SP Science in China Press 53/2(2010-02-01), 203-212 1674-7313 53:2<203 2010 53 11430 https://doi.org/10.1007/s11430-009-0166-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11430-009-0166-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Jia ShiXu Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 700 1- Zhang XianKang Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 700 1- Zhao JinRen Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 700 1- Wang FuYun Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 700 1- Zhang ChengKe Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 700 1- Xu ZhaoFan Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 700 1- Pan JiShun Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 700 1- Liu Zhi Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 700 1- Pan SuZhen Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 700 1- Sun GuoWei Geophysical Exploration Center, China Earthquake Administration, 450002, Zhengzhou, China aut NATIONALLICENCE 773 0- Science China Earth Sciences SP Science in China Press 53/2(2010-02-01), 203-212 1674-7313 53:2<203 2010 53 11430 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer