A Giant Slide within the Upper Cretaceous Limestones as an Indicator for Fault Activity Dating and Basin Evolution

Abstract

The studied section, up to 10m thick with 17 different carbonate beds, showed the interaction between a giant slide and the pre-existing normal faults, during the upper Cretaceous time. There are three major points in the studied section: 1. The presence of two slump horizons, up to 1m thick each, within the stratigraphic column, related with the basin floor instability due to normal listric faults activity. 2. The presence of many normal with listric geometry faults, with a ESE-WNW direction, and mostly west dipping. These faults, acted during the sedimentation processes, produced the basin floor inclination for the slumping, when still the sediments were unconsolidated. This tectonic activity seems to terminate in the upper part of the stratigraphic column. 3. After the development of the slumps and the normal fault activity, that produced a displacement up to 30cm, a new event was characterized the region. The completely studied block rotated to the west and the instability of the sediments produced a giant slide, with up to 7m thick and movement up to 0.9m, cutting the pre-existing normal faults. According to the knowledge of the regional evolution, as it represents the Apulian Platform Margins, with extensional tectonic during Jurassic to early Miocene, that was inverted to compressional regime, during middle Miocene, and the presence of a major fault along the studied section, with a NNW-SSE direction, it seems that the studied section was situated on the hangingwall of the fault, the downthrown block, during the extensional regime.