Print this pageCarbonate Platform-Basin Transition in SW Sicily. Implications for the Petroleum Exploration in the Maghrebian Thrust and Fold Belt
The interplay between paleotectonic structures and the accretion of orogenic wedges is of crucial importance in evaluating the petroleum potential in fold and thrust belts (FTB). A Triassic/Jurassic carbonate platform to basin transition, nearly orthogonal to the thrust propagation, has been recently revealed by the carbonate facies analysis in the Apenninic-Maghrebian FTB from SW Sicily.
The shelf edge records the evolution from an Upper Triassic Dachstein-type reef to a Bahamian-type sandy margin during Early Jurassic times, as consequence of the T/J biotic crysis. Large slope-aprons in adjacent deep-water successions consist of reef-derived carbonate breccias and by oolitic-skeletal turbidites. Middle Jurassic pelagic sediments seal the carbonate system.
A complex Meso-Cenozoic sedimentary dynamics of the shelf margin has been traced on the base of several outcrop sections. Multiple erosional or stepped discontinuity surfaces, swarms of neptunian dykes associated with volcanics and megabreccias account for a Jurassic transtensional activity and a Late Cretaceous basin inversion along the shelf edge. During the Neogene, oblique thrusting along the paleomargin, coupled to right-lateral transpression and clockwise rotations, resulted in a complex stack imbricate. The imbrication of thin tectonic slices of Permian deep-water sediments could suggest that the Triassic paleomargin is a Late Paleozoic inherited structure. The orientation of this paleomargin is nearly parallel to the the NW-SE margin of the Streppenosa basin in the Hyblean region and to the Malta Escarpment. The collected stratigraphic dataset, associated with previous structural interpretations, allows us to suggest that the reconstructed shelf to deep-water transition in SW Sicily (Sciacca area) can be considered as a deformed segment of the rifted southern passive margin of the Permo-Triassic Ionian Tethys.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009