SCOTT, R.W., Amoco Production Company, Tulsa, OK; and J. A. SIMO, Department of Geology and Geophysics, Univ. Wisconsin, Madison, WI

ABSTRACT: Sequence Stratigraphic Models of Economic Deposits in Cretaceous Carbonate Platforms

The study of Cretaceous carbonate platforms was promoted by the initial project of The Global Sedimentary Geology Program: Cretaceous Resources, Events, and Rhythms. one of the three principal goals of GSGP is "To improve the ability to find, produce and husband natural resources in sedimentary deposits" (Ginsburg and Beaudoin, 1990).

Cretaceous carbonate platforms are important sources of economic deposits. New sequence stratigraphic models show the relationships between systems tracts and economic deposits. Also essential are the paleogeographic setting and the paleoclimatic and oceanographic conditions. Many of the world's major oil and gas fields produce from Cretaceous carbonate platforms, and hydrocarbon source rocks were deposited in basins associated with these platforms. Major reservoirs occur beneath disconformable sequence boundaries in highstand aggrading and prograding facies tracts, e.g. Sajaa field, UAE. Fields occur in transgressive facies above sequence boundaries, e.g., Fairway field in the U.S. Gulf coast. Highstand slope deposits are reservoirs in the Tamabra field, eastern Mexico. Karstificatio at composited sequence boundaries forms reservoirs, e.g., the Rospo Mare field on the Apulian Platform, Italy.

Significant reserves of bauxite occur in Cretaceous platform carbonates in humid tropical climates upon karstic sequence boundaries. Tectonic factors may be more important than eustasy in controlling exposure. Iron deposits are associated with sequence surfaces on carbonate platforms in the Basque-Cantabrian basin, Spain, and near diapirs in Algeria. Phosphates are developed on platforms in Albania. Cretaceous carbonate platforms are sources of marble, lime and aggregate.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.