The greywacke zone
is a band of Paleozoic sedimentary rocks
in the Austrian Alps
. The zone is part of the Austroalpine nappes
Mesozoic limestones crop out north of the greywacke zone, forming the Northern Calcareous Alps. South of the zone basement rocks of the Austroalpine and Penninic nappes form the Central Eastern Alps.
The lithologies of the greywacke zone are:
The rocks have formed at a passive margin of the Paleo-Tethys Ocean, when the Austroalpine terrane was part of the microcontinent Avalonia. Together with the other Austroalpine units, they were thrusted over the European plate during the Alpine orogeny.