THE MESOZOIC CENOZOIC EAST CHINA RIFT SYSTEM

The Mesozoic-Cenozoic rift system of eastern China extends in a N-S direction over a distance of some 4000 km and has a width of 600-1000 km. To the east, it reaches into the coastal areas of the East and South China Sea and extends onto the continental shelf. This very large rift system evolved on a heterogenous basement consisting of a number of terranes which were amalgamated during the Indosinian orogeny. A first rifting phase spanned Late Jurassic-Early Cretaceous times. It was followed by a period of relative tectonic quiescence and thermal relaxation. A latest Cretaceous phase of compressional tectonics, giving rise to partial basin inversion. was followed by a renewed rifting cycle spanning Eocene Early Neogene times. Development of the East China rift system, involving vertical as well as lateral crustal movements, was probably induced by physico-chemical changes within the Earth's mantle that can be related to activity along the Pacific subduction zones. The Mesozoic-Cenozoic East China rifts contain some important hydrocarbon provinces which rely to a large extent on syn-rift sediments for source and reservoir rocks.