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Anlin Guo, northwest university (China)
Guowei Zhang, northwest university (China)
Juan Qiang, northwest university (China)
Yangui Sun, northwest university (China)
Guang Li, northwest university (China)
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The Zongwulong tectonic belt situated in between the Northern Qaidum Tectonic Zone and the Southern Qilian orogen is composed of late Paleozoic and early-middle Triassic strata as well as Carboniferous ophiolite and Permian arc intermediate-acid volcanics. Three Hercynian-Indosinian granites: the Tianjunnanshan (248 Ma), Qinghaihunanshan (238 Ma) and Erlangdong (215 Ma) granites outcropping in the southern Zongwulong belt are associated with subduction and post collision stages, respectively. Two obvious deformation phases represent the Indosinian orogenic structures and Tertiary intracontinental tectonic imprints. The former is characterized by a more than 300 km long and a few km wide ductile shear zone and the latter mainly is large-scale and south-verging thrusting. Different from the Northern Qaidum Tectonic Zone to its south and the Qilian Orgen to its north, the Zongwulong tectonic zone is an independent Indosinian organic belt which was developed on the early Paleozoic Caledonian orogenic basement and experienced a complete plate tectonic evolution of continental rifting, oceanic basin and sunduction-coliision.
To east via the Qinghaihunanshan and the Xiangpishan areas, the late Paleozoic and early-middle Triassic sedimentary association of the Zongwulong belt can connect with the contemporaneous Shangdan relict marine basin of the west Qinling orogenci belt. This setting gives the Zongwulong belt a critical position in the interrelationship between the Qinling, Kunlun and Qilian orogens. The late Paleozoic rifting of the belt separated the jointed three orogens from one another, while during the Indosinian orogenesis, the close-up of the Zongwulong belt welded the separated orogens together, forming a final amalgamation of the Qinling-Kunlun-Qilian orogens in China continent.
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