Episodic rifting and subsidence in the South China sea

Journal Article · Mon Sep 01 04:00:00 EDT 1986 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6887650

Ru, K; Pigott, J D

The South China Sea experienced at least three stages of rifting and two intervening stages of sea-floor spreading since the Early Cretaceous. Its evolution can be described by an episodic model of tectonism, one of thermal cooling and subsidence, pulsed by temporally and spatially confined heating events. Analysis of regional geologic and geophysical data suggests episodes of rifting and associated thermal activities initiated during the Late Cretaceous, the late Eocene, and the late early Miocene. The rift system corresponding to the first episode trends northeast-southwest, whereas those of the second and third trend east-west. These two trends coincide with the orientations of the major tectonic lineations within the basin. Age estimates from heat-flow and bathymetric data suggest the oceanic crust in the Southwest subbasin is considerably older (55 Ma) than that in the Northwest (35-36 Ma) or East (32 Ma) subbasins. In terms of hydrocarbon potential, the episodes of rifting and drifting would be conducive to the development of overprinted structures and the deposition of several discrete transgressive packages of source rocks and reservoirs, separated by widespread unconformities. The thermal maturity of sedimentary organic matter affected by episodic rifting and subsidence may be greater than expected on a purely passive margin of equivalent age that had not experienced repeated heating. 21 figures.

• Research Organization: Univ. of Oklahoma, Norman
• OSTI ID: 6887650
• Journal Information: Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 70:9; ISSN AAPGB
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ASIA
CHINA
CRETACEOUS PERIOD
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GROUND SUBSIDENCE
MESOZOIC ERA
MINERAL RESOURCES
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCES
SEDIMENTARY BASINS
SOURCE ROCKS
TECTONICS