Regional Tectonic Characters And Meso-Cenozoic Basin Evolution In Northeastern China

Northeastem(NE) China, located between Siberian plate and North China plate, contains many Meso-Cenozoic basins. It is one of significant petroleum industrial bases and has broad exploration prospects. Based on plate tectonic theory, this paper mainly discusses regional tectonic characters and Meso-Cenozoic basin evolution and its geodynamic background in NE China, by combining basin and its tectonic evolution with orogeny, and by using methods of field geology survey and indoor synthetic analysis. Fieldwork includes the studies of regional tectonic characters and typical cross sections;and regional tectonic characters, seismic section and structural history profiles are analyzed synthetically in door based on seismic and well-logging data. In addition, synthetic analyses of litho-geochemical characteristics, stratigraphy sequence and sedimentary facies are adopted in this paper. The main results are summarized as follows:1. Tecto-orogenic processes of Pre-Mesozoic can be mainly characterized by amalgamation among different plates and finally collides with Siberian plate and North China plate. Multistage and different directions amalgamation orogenesis forms orogenic belts with different structural directions.2. Basin evolution in NE China goes through four stages: early Jurassic rift basin, middle-late Jurassic partitioned foreland basin, late late Jurassic-Cretaceous rift basin and Cenozoic rift basin. Early Jurassic rift basin is typified by small scale basins with E-W distribution in Daqingshan in Inner Mongolia and Yanshan area. Middle-late Jurassic partitioned foreland basins are mainly distributed in Erlian area, southeast Songliao basin and Yanshan area, with a distribution direction of nearly EW or NE on the whole. Late late Jurassic-Cretaceous rift basins are typified by Erlian-Hailaer basin, Songliao basin and Sanjiang basin, which could be divided into west, central and east zone. Basin evolution can be clearly divided into two rift episodes and one inversion compression episode. Cenozoic rift basin is characterized by linear distribution along Yilan-Yitong fault and Dunhua-Mishan fault.3. Meso-Cenozoic basin evolution in NE China is controlled by interactions ofneigbouring plates and deep structural process. Plate collision was quiet in early Jurassic in Eastern China and post-orogenic extension collapse has begun to occur in some place in NE China. During middle-late Jurassic. East China went through paleo-pacific plate subduction in SE Asia and subduction and collision of Okhotsk ocean;and partitioned foreland basin controlled by thrusting were formed in NE China. In late Jurassic-Cretaceous, the main drives for complicated zoned-basins include extension and collapse of thickened lithosphere, deep underplating, delamination and the strike-slip subduction of Paleo-Pacific margin. In Cenozoic typical back-arc rift basins are formed in NE China where is the back-arc area of pacific plate subduction zone.