Contrasting styles of siliciclastic flysch sedimentation in the Upper Cretaceous of the Silesian Unit, Outer Western Carpathians: sedimentology and genetic implications

Abstract

This study reports on a new set of sedimentological data and related interpretations of the Santonian– Campanian siliciclastic deposits in the Western Flysch Carpathians based on natural outcrops in the uppermost Godula Formation and lowermost Istebna Formation. The rationale was to confront the characteristics of this flysch succession with current controversies and state of knowledge on deep-water clastic sedimentation. The sedimentological analysis of the field data allowed for multi-scale synthetic classifications of the depositional components in the investigated flysch. The hierarchical and practical nature of the suggested classification schemes allows for their application to similar deposits in other regions. The siliciclastic deposits are products of gravity-driven terrigenous sediment redeposition via submarine slumps, debris flows, and turbidity currents. Sediment reworking by tractional bottom currents is considered as an accompanying factor. Point-sourced turbiditic fan lobe fringes from the submarine piedmont ramp and linearly supplied debritic covers along the slope apron are proposed as dominant. The innovative linking between the textural-structural descriptive features of the deposits and the critical determinants of specific sediment gravity-flow processes and architectural elements of the deepwater clastic depositional systems is a significant contribution to this research field.