Abstract: Structural Control on Lithofacies in the Zhu 1 Depression, Pearl River Mouth Basin, South China Sea

John B. Carnes, Joyce M. Novitsky-Evans, David J. Schunk

The structural framework of the Zhu 1 depression, Pearl River Mouth Basin, South China Sea, is expressed in terms of a half-graben rifting model, providing foundation for a predictive model of synrift lacustrine source rock distribution. The Zhu 1 depression includes a northern series of linked half grabens, a southern series of linked half grabens, and a central chain of intrabasinal ridges. The central ridge chain includes both horst blocks (termed high-relief accommodation zones or isolation ridges in the model) and antiforms (termed low-relief accommodation zones or interference ridges in the model). Major fluvial input was from the north, funneled into Zhu 1 through gaps (termed platforms in the model) created by offsets in the border faults of the northern series of half grabens The central ridge chain is interpreted to have controlled sediment distribution within Zhu 1, periodically confining coarse terrigenous clastics within northern half grabens while lacustrine shales accumulated in southern half grabens.

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