Hoh Xil - Bayan Har Triassic Sedimentary Basin Formation And Evolution

The Hoh Xil-Bayan Har Triassic sedimentary basin, which is located in the northeast of Qinghai-Tibet Plateau hinderland, is tectonically bounded by Muztag-South of eastern Kunlun- A'nyemaqen in the north, by Xijir Ulan-Yushu-Jinsha River fault zone in the south, and by Longmenshan nappe structure zone in the east. It's shape likes a huge inverted delta with an area of over 70 sq. kilometers. Sediments in the basin primarily belong to the Triassic turbidite, up to 10×10~3meters in thickness. Because of Hoh Xil-Bayan Har's special geotectonical position and complex genesis, it has been a hotspot and key area in studying Qinghai-Tibet Plateau geotectonics and Tethys. On account of alpine hypoxia, bad weather , poor traffic and other many difficulties as well as low degree in studying, the region is geologically called "Bermuda Triangle". The Hoh Xil-Bayan Har area not only is rich in mineral resources, but also is a birthplace from which many rivers come. And the Qinghai-Tibet highway and railway cross the Hoh Xil in the western region of the basin , Sanjiangyuan nature reserve, Hoh Xil nature reserve and the western route water transfers project from south to north are situated here. So the research on Hoh Xil-Bayan Har Triassic sedimentary basin has important theoretical value and practical significance.Previous studies are mostly restricted to geological tectonics, regional stratigraphy, paleontology and geophysics, etc. The writer has acquired many detailed firsthand basic information by field geological mapping and scientific expedition for a decade.By the formation and evolution of Hoh Xil-Bayan Har Triassic sedimentary basin under the global tectonic framework of Gondwandland split and paleotethys domain, through the theoretical guide on activity and plate tectonics, and research on sedimentary features, paleocurrent, provenance, abyssal radiolarian cherts and magmatism related to the basin, such as basic dyke swarm, ophiolite and subduction arc volcanics, etc. It has been considered a typical remnant ocean basin, moreover, the process of formation and evolution of Hoh Xil-Bayan Har sedimentary basin has been demonstrated.The tectonic realm of Hoh Xil-Bayan Har sedimentary basin includes Muztag- Kunlun-A'nyemaqen tectonic zone, Western Qinling tectonic zone, Hoh Xil-Bayan Har tectonic province and Xijir Ulan-Yushu- Jinsha River tectonic zone from the north to the south, in which the distribution of lithostratigraphy and the characteristics of stratigraphic sequence reflect the filling and distributional laws of strata in the sedimentary basin in different settings and times.The Carboniferous-Middle Permian accretion zone melange abound in Muztag- Kunlun-A'nyemaqen tectonic zone in the southern edge of basin, including ophiolite and abyssal radiolarian cherts association. The Hoh Xil-Bayan Har main tectonic region abound with the...