Sedimentation of submarine fan deposits in the Pindos foreland basin, from late Eocene to early Oligocene, west Peloponnesus peninsula, SW Greece

摘要

Turbidite facies distribution and palaeocurrent analysis of submarine fan evolution in the Pindos foreland basin of west Peloponnesus peninsula (SW Greece) indicate that this part of the foreland was developed during Late Eocene to Early Oligocene in three linear sub-basins (Tritea, Hrisovitsi and Finikounda). The basin fill conditions, with a multiple feeder system, which is characterized by axial transport of sediments and asymmetric stratigraphic thickness of the studied sediments, indicate that the Pindos Foreland Basin in this area was an underfilled foreland basin. Sediments are dominated by conglomerates, sandstones and mudstones. The flow types that controlled the depositional processes of the submarine fans were grain flows, debris flows and low- and high-density turbidity currents. The sedimentary model that we propose for the depositional mechanisms and geometrical distribution of the turbidite units in the Tritea sub-basin is a mixed sand-mud submarine fan with a sequential interaction of progradation and retrogradation for the submarine fan development and shows a WNW main palaeocurrent direction. The Hrisovitsi sub-basin turbidite system characterized by small-scale channels was sediment starved, and the erosion during deposition was greater than the two other studied areas, indicating a more restricted basin topography with a NW main palaeocurrent direction. The Finikounda sub-basin exhibits sand-rich submarine fans, is characterized by the presence of distinct, small-scale, thickening-upward cycles and by the covering of a distal fan by a proximal fan. It was constructed under the simultaneous interaction of progradation and aggradation, where the main palaeocurrent direction was from NNW to SSE.