Geology and Petroleum Systems of the East China Sea Basin

Abstract

The back-arc East China Sea Basin lies on extended continental crust at the leading edge of the Eurasian plate. In this study, the basins are described and subdivided according to their tectono-stratigraphic evolution. In order to distinguish between different phases of deformation in basin development, standard basin evolution patterns related to geodynamic drivers are identified as a first step. On the basis of this, standard patterns are recognized in the sedimentary sequences that characterize the area and its tectonic evolution, and linking them to the petroleum systems present is attempted. This is achieved by characterizing and grouping them into basin cycle-related petroleum system types (PSTs). Finally, the development of plays is examined within the petroleum systems in the context of their tectono-stratigraphic evolution, and groups of sub-basins with similar geological history and, therefore, potentially similar petroleum prospectivity are identified. In the East China Sea Basin, four proven and potential PSTs were recognized: (1) Late Cretaceous to Paleocene oil/gas-prone early syn-rift lacustrine–deltaic PST; (2) Eocene gas/oil prone late syn-rift marine PST; (3) Oligocene to Middle Miocene gas/oil-prone early post-rift fluvial–deltaic PST; (4) gas-prone syn-rift turbiditic PST. The geology and petroleum systems of three major sub-basins of the East China Sea Basin, the Xihu Sub-basin, the Lishui Sub-basin, and Okinawa Trough, are discussed in detail, and their petroleum systems and play development are analyzed. Finally, the sub-basins are grouped into “basin families” distinguished by their tectono-stratigraphic development, namely, Northwest to Northeast Shelf Basin (NWSB–NESB), Southwest to Southeast Shelf Basin (SWSB–SESB), and Okinawa Trough basin families, respectively.

Source‐To‐Sink Links Between East Asia and Taiwan From Detrital Zircon Geochronology of the Oligocene Huagang Formation in the East China Sea Shelf Basin

“…Alternatively, it is also possible that Oligocene sediment in the Xihu Sag and EDB were sourced from nearby structural highs, highs to the north, and/or from the Taiwan‐Sinzi belt to the east (Qin et al, ; Wang et al, ; Yang et al, ). Several recent provenance studies have concluded that the Precambrian zircons in Oligocene units in the Xihu Sag were sourced from basement to the north of the Xihu Sag (Wan & Zhang, ; Qin et al, ).…”

“…Several recent provenance studies have concluded that the Precambrian zircons in Oligocene units in the Xihu Sag were sourced from basement to the north of the Xihu Sag (Wan & Zhang, ; Qin et al, ). Although this possibility cannot be evaluated directly because the age of potential basement sources is unknown, Proterozoic rocks that are an eastward extension of the South China Block may underlie the region (Wang et al, ; Yang et al, ). Early international boreholes located close to the Hupingjiao Uplift, north of Xihu Sag, encountered a series of gneiss and schist (JDZ‐V‐2 by Japan, KV‐1 by South Korea) interpreted to be Precambrian in age (Wang et al, ; Yang et al, ).…”

“…Although this possibility cannot be evaluated directly because the age of potential basement sources is unknown, Proterozoic rocks that are an eastward extension of the South China Block may underlie the region (Wang et al, ; Yang et al, ). Early international boreholes located close to the Hupingjiao Uplift, north of Xihu Sag, encountered a series of gneiss and schist (JDZ‐V‐2 by Japan, KV‐1 by South Korea) interpreted to be Precambrian in age (Wang et al, ; Yang et al, ). Additional age data are needed, however, to confirm or reject this hypothesis.…”

“…Geochemistry, Geophysics, Geosystems to the Hupingjiao Uplift, north of Xihu Sag, encountered a series of gneiss and schist (JDZ-V-2 by Japan, KV-1 by South Korea) interpreted to be Precambrian in age Yang et al, 2010). Additional age data are needed, however, to confirm or reject this hypothesis.…”

Control of strike‐slip and pull‐apart processes to tectonic transition of the southern East China Sea Shelf Basin

“…Division of strata and tectonic stages of the ECSSB (AfterYang, Cui, & Zhang, 2010) its strike-slip property, and there are also some small half-grabens developed inside it. By comparison, in the east, structural types of the Minjiang and the Jilong sags are consistent.Without any flower-like structures, the two sags are characterized by extensional structures like grabens and half-grabens.…”