ABSTRACT: Petroleum Geologic Characteristics of East China Sea Basin

Li Desheng

The East China Sea is a major Cenozoic epicontinental rift-depression basin, covering an area of 770,000 km². The basin is bounded by the Minzhe uplift to the west and by the Ryukyu Island arc to the east. The thickness of sedimentary strata is greater than 10 km. Basin evolution has been dominated by taphrogenesis and orogenesis attributable to the westward subduction of the Pacific plate. The basin history of the East

China Sea can be divided into four stages: (1) Late Cretaceous-Paleogene rifting stage, (2) Eocene-Oligocene rifting-depression stage, (3) Miocene depression stage, and (4) Pliocene-Quaternary draping stage. The Okinawa Trough is a new rifting zone related to the subduction of Ryukyu Island arc. Recent geophysical exploration and petroleum drilling activities in the East China Sea basin show that Paleogene lacustrine and Neogene marine facies strata include multiple suites of hydrocarbon source rocks. Eight structures have tested gas and oil. The Pinghu gas and oil field was discovered and delineated on the west slope of Xihu depression. Various types of traps, dome anticlines, rollover anticlines, fault blocks, buried hills, and reef carbonates, are good prospects.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990