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Geology
Published in Ronald C. Chaney, Marine Geology and Geotechnology of the South China Sea and Taiwan Strait, 2020
A bathymetric map of the strait is presented in Figure 2.12. A review of this figure shows the presence of both shallow and wide shelves covered by water in the East China Sea, the Taiwan Strait, and the SCS along the southeastern Chinese margin. The Huatung Basin with water depths between 4000 and 5000 m lies off the eastern Taiwan coast. North-east of Taiwan lies the back arc basin of Okinawa. The deepest submarine feature of this basin is the Ryukyu Trench, which is south of the Ryukyu Arc with a minimum water depth of more than 6000 m. The deep oceanic Huatung basin is bounded by the Gagua Ridge and N–S trending ridges and troughs with irregular surface characterize the seafloor off southwestern Taiwan. Off south-eastern Taiwan a broad submarine slope dips down to 3000 m in water depth. This slope is dissected by numerous canyons juxtaposed with the SCS slope.
Tectonics and Sedimentation
Published in Supriya Sengupta, Introduction to Sedimentology, 2017
Seismically active subduction zones mark the converging plate margins. On the landward side of these subduction zones, which dip towards the continents, lie volcanic island arcs. On the seaward side occur deep-sea trenches. Orogenic belts are produced out of collision of the lithospheric plates. Intrusion of the subducted material into the lower crust causes doming of the igneous and metamorphic terranes at the zone of convergence, into what are called ‘arc massifs’. These elevated areas at the basin margins serve as the source of sediments while the sediments themselves are deposited in one of the following five areas: within the ocean, on the down-going oceanic plate, within the deep-sea trench, in small basins on the slope of the inner wall of the trench, seaward of the volcanic arc (outer-arc or forearc basin), and behind the volcanic arc (back-arc basins).
Magmatism in the Context of the Present-Day Tectonic Settings
Published in O.A. Bogatikov, R.F. Fursenko, G.V. Lazareva, E.A. Miloradovskaya, A. Ya, R.E. Sorkina, Magmatism and Geodynamics Terrestrial Magmatism Throughout the Earth’s History, 2020
O.A. Bogatikov, V.I. Kovalenko, E.V. Sharkov, V.V. Yarmolyuk
The stress regime changes across the strike of the island-arc system (i.e. from the fore-arc to the arc to the back-arc basin). According to Fedotov et al. (1985) the deep-sea trench is fronted by a stress zone about 200 km wide, manifested by a shallow (up to 50 km) earthquake belt (Fig. 2.4). The earthquake depth shows a regular increase, up to 700 km deep away from the trench toward the continent. The density of earthquake foci decreases drastically at depths of 140–180 km at the site of intersection of the subducted plate by the bases of the volcanoes. Back -arc basins are characterized by a tensional regime, accompanied by sea-floor spreading and submarine basaltic volcanism.
Characteristics of fluid potential and division of hydrocarbon migration and accumulation units in the Shijiazhuang Sag
Published in Petroleum Science and Technology, 2021
Chen Liang, Wenlong Ding, Jia yi Zhou, Ruyue Wang, Ruiqiang Yang
The late Mesozoic started from Late Jurassic to early Cretaceous and was in a period of intense extension. The subduction of the Pacific plate caused back arc extension. Metamorphic core complex and magmatic activity were widely developed in the eastern part of the North China Craton, which resulted in large-scale lithospheric thinning in the eastern part of the craton and formed a series of contemporaneous faulted basins.