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Keywords:

  • Canyon fill;
  • Crotone;
  • density-flow deposits;
  • Pleistocene;
  • regional uplift;
  • sea-level changes

Abstract

A middle Pleistocene coarse-grained canyon fill succession (the Serra Mulara Formation) crops out in the northern sector of the Crotone Basin, a forearc basin located on the Ionian side of the Calabrian Arc and active from the Serravallian to middle Pleistocene. This succession is an example of coarse-grained submarine canyon fill, which consists of a north-west to south-east elongated body (4·25 km long and up to 1·5 km wide) laterally confined by a deep-water clayey and silty succession and located behind the modern Neto delta (north of Crotone). The thickness of the unit reaches 178 m. The lower part of the canyon fill is dominated by gravelly to sandy density-flow deposits containing abundant bivalve and gastropod fragments, passing upward into a succession composed of metre-scale to decimetre-scale density-flow deposits forming sandstone–mudstone couplets. Sandstone deposits are mostly structureless and planar-laminated, whereas the clayey layers record hemipelagic deposition during quieter phases. This succession is overlain by another composed of thicker structureless sandstones alternating with layers of interlaminated mudstones and sandstones, which contain leaf remnants and fresh water ostracods, and are linked directly to river floods. The canyon fill is overlain by gravelly to sandy continental deposits recording a later stage of emergence. Facies analysis, together with micropalaeontological data from the hemipelagic units, suggests that the studied canyon fill records, firstly, a progressive gravel material cut-off during deposition due to an overall relative sea-level rise, leading to a progressive increase in the entrapment of sediment in fluvial to shallow-marine systems, and secondly, a generalized relative sea-level lowering. This trend probably reflects high-magnitude glacio-eustatic changes combined with the regional uplift of the region, ultimately leading to emergence.