Facies Variation and Evolution of a Peri-Adriatic Carbonate Platform in the Region of Sorrento, Southern Italy

J. Robson

In the region around Sorrento, Cretaceous carbonates attributed to inner platform facies outcrop, and farther south lithologies indicate deposition in a foreslope/basin environment. Sedimentological logging shows significant changes in facies associations from the Aptian to the Cenomanian-Turonian. These changes indicate variation in depositional environment through time with respect to the stability of the western margin of the platform.

Aptian rocks of restricted platform facies (dolostones, poorly fossiliferous dolomicrites, and micrites) are overlain by sediments of higher-energy shoal environments (rudist rudstones/floatstones and cross-bedded bioclastic grainstones). Basal Albian sediments indicate deposition in an intertidal environment with the recurrence of dolomicrites and ostracod wackestones. In contrast, upper Cenomanian-Turonian sediments include rudist rudstones/floatstones, foraminiferal wackestones, micrites, and occasional bioclastic grainstones. These facies are attributed to an open marine lagoon or back-reef environment. The youngest exposed Cretaceous carbonates are represented by bioclastic debris flows of platform detritus which pass abruptly into Tertiary pelagic mudstones. These have been inte preted as representing the western margin of the platform.

This sequence represents part of the Campania-Lucania platform, which has been described as analogous to the present-day Bahamas: a fault-bounded platform with deep marginal basins. Although there is evidence for fault control along the eastern margin of the Campania-Lucania platform, this does not appear to be the case for the western margin. The Bahamian model must be substantially modified to accommodate the patterns of sedimentation seen in the Campania-Lucania platform.

AAPG Search and Discovery Article #91032©1988 Mediterranean Basins Conference and Exhibition, Nice, France, 25-28 September 1988.