The structural geology of the Rapid Bay – Second Valley area, South Australia

Abstract

The area is structurally homogeneous with respect to a single fold axis.

The style of folding is recumbent, with the axial plane dipping gently to the east. It is postulated that the anticlines close \to the south, in accord with the regional anticlinorium. Extensive thrust faulting has accompanied this folding.

There is some evidence for a second, minor period of deformation superposed on the first.

The pressure exerted during the intense folding of the area is thought to be the dominant cause of metamorphism, with only relatively low temperatures involved. The rocks contain low grade mineral assemblages, and are assigned to the quartz m- albite – epidote – biotite subfacies of the greenschist facies.