Seismic stratigraphy of the north-westernmost area of the Malta Plateau (Sicily Channel): The Middle Pleistocene-Holocene sedimentation in a tidally influenced shelf

In this study we present the results of a seismic-stratigraphic analysis of sub-bottom profiles in the north-westernmost area of the Malta Plateau in order to define the depositional mechanisms for the upper Quaternary sequences. During this interval the morphology of the Malta Plateau was characterized by a ramp and bathymetries not exceeding 200 m. Two major unconformities, related to MIS 6 and MIS 2 (the latter corresponding to the Last Glacial Maximum, LGM), characterize the upper Quaternary sequences. The geometries of the recognized seismic units indicate as depositional mechanisms were controlled by subsidence and sea-level fluctuations. In detail, deposits related to the last glacial event were recognized through their seismic pattern and have been interpreted as formed by the interaction between tide and wave dynamics. Contrary to the northern Sicilian continental margin, in the Malta Plateau ramp no LGM-related lowstand prograding wedge was recognized due to the absence of an effective shelf edge. It is considered as a consequence of the morphology and the dominant deposition processes in the Malta Plateau. Afterwards the ramp morphology allowed a rapid drowning of the Malta Plateau instead with the formation and preservation of transgressive deposits revealed as bedforms. The highstand deposits appear as prograding bodies and have been classified as infralittoral prograding wedge.