Syndepositional tectonics affecting Cenozoic and Mesozoic deposition in the Malta and SE Sicily areas (Central Mediterranean) and their bearing on Mesozoic reservoir development in the N Malta offshore region

Abstract

Tertiary sedimentation patterns within the Maltese Islands and SE Sicily (Pelagian Block of the Central Mediterranean) reflect subtle depositional control by the concurrent evolution of the Malta Graben, lying to the south-west, and reactivation of regionally important Mesozoic fault systems. The visible structural style of the Maltese Islands is the product of Malta Graben development and commenced some 24 million years ago. However, north-south oriented structures, identified from Maltese Tertiary facies strike patterns, can be closely related to reactivated Mesozoic faults in SE Sicily. Here, synsedimentary tectonogenesis is recognized in both Mesozoic and Cenozoic strata. Mesozoic synsedimentary faulting was initiated during a former tectonic regime when the Pelagian Block (African Plate) lay at the southern side of a wide Tethys ocean. Reactivation of these fractures during the Tertiary is believed to be related to subsequent African-European plate collision. The unsuccessful oil search in Maltese territorial waters results from the mistaken significance attached to the young, Malta Graben related tectonic pattern of the Maltese Islands. Potential traps are more likely to be associated with a cryptic though formerly dominant Mesozoic tectonic pattern. The hypothesis presented predicts hydrocarbon prospects in horst traps immediately to the north of the Malta shelf. These can be expected to show many of the characteristics of the Gela and Ragusa fields.