Characteristics and origin of fluxoturbidites from the Carpathian flysch (Cretaceous-Palaeogene), South Poland

Abstract

Fluksoturbidyty z fliszu polskich Karpat: ich cechy charakterystyczne, geneza oraz pozycja w aktualnych schematach klasyfikacji osadów Selected beds (164) of coarse-clastic resedimented deposits, traditionally called fluxoturbidites, were described in detail from various flysch formations (Cretaceous - Palaeogene) of the Polish Carpathians, with particular emphasis given to texture, sedimentary structure and bedding characteristics. The beds were classified into three textural groups. For each of these groups model beds were generated, using vertical-transition count technique. The ideal bed for conglomeratic fluxoturbidites (group CS) and that for pebbly sandstone fluxoturbidites (group PS) correspond basically to Lowe’s (1982) model beds of the deposits of high-density gravelly and sandy turbidity currents, respectively. The ideal bed of sandstone fluxoturbidites (group S) corresponds to the classical turbid'ite showing expanded Bouma Ta division overlain by reduced sequence Tb-e. The classical fluxoturbidites are thus interpreted as the deposits of high-density turbidity currents, although other mechanisms, including cohesionless debris flows and fluidized flow, may have also contributed locally. Composite beds which dominate in the fluxoturbidites represent an effect either of amalgamation of several separate flow events or deposition from surging flows.