Regional inter-relationships in the Proterozoic geology of Bergslagen and Southeastern Central Sweden

Abstract

The regional tectonic and metamorphic features common to western Bergslagen and to the region lying to the east are described. Metamorphic grade varies from low grade greenschist facies in the west to higher grade amphibolite facies in the east, where migmatized gneisses are also developed. Deformation is also stronger in the eastern region, where E-W trending isoclinal folds predominate, while N-S trending, more open structures are found to the west. Stratigraphic and lateral inter-relationships of the two regions indicate a volcanic proximal area in western Bergslagen, which fed tephra into a depositional basin to the east.