Suo Y.,Ocean University of China |
Suo Y.,Key Laboratory of Submarine Geosciences and Exploration Technique |
Li S.,Ocean University of China |
Li S.,Key Laboratory of Submarine Geosciences and Exploration Technique |
And 5 more authors.
Acta Petrologica Sinica | Year: 2012
Tectonic migration is common geological process of basin formation and development. However, little is known for tectonic migration on the Western Pacific margins. This paper focuses on the representative regions of East China and its surrounding seas in the Western Pacific domain to discuss Cenozoic tectonic migration and mechanism based on our and previous structural results of the Bohai Bay Basin, South Yellow Sea Basin, East China Sea Shelf Basin and South China Sea Basin and others. The Western Pacific active continental margin is the eastern margin of global convergent system located in the junction among the Eurasia Plate, the Pacific Plate and the India Plate. Under the effects of the India-Eurasia collision and retrogressive or roll-back subduction of the Pacific Plate, the Western Pacific active continental margin has a wide basin-arc-trench system which migrated and jumped eventually seaward and eastward. The migration and jumping are characterized by progressive eastward younging of faulting, sedimentation, depression, termination in and/or within basins, and generation, reservoir, seal, trap, migration and preservation of hydrocarbon and gashydrate. Due to the tectonic migration, the conditions related to hydrocarbon and gashydrate accumulation of East China and its adjacent lands and seas also get younger from west to east, and such a spatio-temporal distribution of Cenozoic hydrocarbon and gashydrate is significant for the oil and gas exploration in East China. Finally, this paper discusses the mechanism of Cenozoic intrabasinal and interbasinal tectonic migration in terms of interplate, intraplate and underplating processes. The migration or jumping mechanism of tectonism-magmatism-basin foramtion- hydrocarbon-gashydrate accumulation is the Late Mesozoic extrusion tectonics and the Cenozoic NW-directed crustal extension, the regional far-field eastward flow of the western asthenosphere due to the India-Eurasia plate collision accompanying with eastern jumping and back-rolling of subduction zones of the Pacific Plate.