Abstract: Seismic Sequence Stratigraphy of the East China Sea

Walter W. Wornardt, Peter R. Vail, Jim Zewei Zhang, Li Peilian, Lyle F. Baie

Interpretation of the relationships of the second- and third-order depositional sequences, their sequence boundaries, maximum flooding surfaces, low stand and high stand systems tracts, and their surfaces were made on three wells in the East China Sea. The age of the sediments is based on the integration of calcareous nannofossils, planktonic, benthic and large forams, and palynomorphs. The maximum flooding surfaces, sequence, and systems tract boundaries were identified and annotated on well logs and on a sequence stratigraphy analysis chart. These surfaces and boundaries on well logs were correlated with a series of seismic reflection profiles.

The lacustrine-fluvial sediments in the Shi Men Tan 1 well were correlated to similar sediments in the Ming Yue Feng 1 well. Lowstand systems track slope fan complexes, that were deposited at the same time as the Andrews and Forties fans in the North Sea, were found in the Shi Men Tan 1 and Ming Yue Feng 1 wells. The slope-fan complexes were deposited in upper bathyal water depths (200-500 m) based on benthic foraminifers. Coastal swamp lagoonal sediments identified in the three wells could be the source rocks for hydrocarbon accumulations in the channels or channel overbank deposits in the slope-fan complexes and the lowstand prograding complexes. Stratigraphically above these deposits, nummulite carbonate banks were identified in the Shi Men Tan 1 and the Ling Feng 1 wells. Several ignificant angular unconformities were recognized at various intervals in the three wells.

AAPG Search and Discovery Article #90982©1994 AAPG International Conference and Exhibition, Kuala Lumpur, Malaysia, August 21-24, 1994