Cretaceous flysch and pelagic sequences of the Eastern Alps: correlations, heavy minerals, and palaeogeographic implications

Abstract

Flysch and pelagic sedimentation of the Penninic and Austroalpine tectonic units of the Eastern Alps are results of the closure of the Tethyan-Vardar and the Ligurian-Piemontais Oceans as well as of the progressive deformation of the Austroalpine continental margin. The Austroalpine sequences are characterized by Lower Cretaceous pelagic limestones or minor carbonate flysch and various siliciclastic mid- and Upper Cretaceous flysch formations. Chrome spinel is the most characteristic heavy mineral delivered by the southern Vardar suture, the northern obduction belt at the South Penninic-Austroalpine margin and its continuation into the Klippen belt sensu lato of the Carpathians. The South Penninic sequences, e.g. the Arosa zone, the Ybbsitz Klippen zone and some flysch nappes also contain chrome spinel, whereas the sediments of the North Penninic Rhenodanubian flysch zone are characterized by stable minerals and garnet.