The Austro-Alpine Quartzphyllites and Related Palaeozoic Formations

Abstract

The Austro-Alpine quartzphyllites and related clastic- and volcanic-rich sequences are interpreted as the infilling of an Early Ordovician to Early Carboniferous basin. The basin may have been initially formed as a back-arc basin on a Late Cadomian/Pan-African metamorphic crust during the Ordovician. A pulse of renewed rifting during Silurian and Early Devonian probably led to the opening of a nearby oceanic basin and formation of a passive margin which is mainly represented by a Middle to Late Devonian carbonate platform. Contraction and basin closure occurred during Visean to Early Westphalian. It was accompanied by: (i) rapid subsidence due to lithospheric loading by thrust sheets, (ii) formation of a foredeep with orogenic flysch deposits in front of incoming thrust sheets, and (iii) weak metamorphic processes.