LOIACONO F.
Facies di conoide alluvionale nei depositi Pleistocenici del bacino di S. Arcangelo (alta valle del F. Sinni) – Recognition of alluvial fan in the Pleistocenic deposits of St. Arcangelo Basin (upper F. Sinni valley)
Pages 31-38
Abstract
Preliminary results of sedimentological researches carried out on Plio-Pleistocenic deposits of the Sant’Arcangelo basin are reported. Alluvial fan deposits are recognized in the western area. Three facies are distinguished: facies A, due to debris flow, reveals a fanhead in the western sector; facies B, due to stream flood and sheet-flood, and facies C, as channelled deposits, show an evolution to water-laid deposits. A dispersal pattern, inferred from pebble imbrication, reveals north-western provenance of detrites in the western outcrops, and some eastward coalescing alluvial fans. The relationships between setting, thickness and distribution of coarse-grained facies and the deltaic facies of the eastern part of the basin, suggest the existence of a basin affected by a general uplift, more remarkable along its eastern margin that could limited the axial development of alluvial fans. The western and southern margin were represented by fault escarpments.