EBERLI, GREGOR P., University of Miami, Miami, FL; DANIEL BERNOULLI and DIETHARD SANDERS, Geological Institute, ETH, Zurich, Switzerland; and ADAM VECSEI, Technische Hochschule, Darmstadt, Germany

ABSTRACT: Aggradation to Progradation of the Cretaceous Maiella Platform (Italy) and of Its Tertiary Counterpart, the Great Bahama Bank

In the Maiella Mountains (Italy), the exhumed Lower Cretaceous to Upper Miocene portion of the Apulian platform displays an excellent example for (1) the evolution of an isolated platform with a steep escarpment, (2) a Cretaceous platform that did not drown in the mid-Cretaceous but was instead subaerially exposed during the late Albian to early Cenomanian, and (3) a platform transformation from aggradation to progradation. This two-stage evolution is analog to the early development of Great Bahama Bank (GBB). In both cases, the initial topography was responsible for the timing of progradation as excess relief had to be buried prior to progradation.

During the aggradational stage, the Maiella platform was non-rimmed and stationary. On the platform rudist biostromes, calcareous sand waves, peritidal and lagoonal sediments accumulated, while the escarpment was onlapped by basinal sediments. Platform aggradation was several times interrupted by erosional phases during which deep channels were cut into the margin. The channels were subsequently filled with coarse-grained breccias, bioclastic sand and silt over which peritidal carbonates and rudist biostromes re-established. This facies succession demonstrates how destructive processes compete with the growth potential of a platform. During the Campanian, the escarpment became buried by the onlapping strata enabling the platform to prograde.

This platform development is similar to the evolution of GBB. Most striking is the similar anatomy that developed during the transformation of the escarpment into a progradational slope. We speculate that facies distribution

and processes are similar in both platforms and their evolution might reflect a common pattern during expansions of shallow-water facies belts.

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