A kinematic analysis of the southernmost part of the Bega Batholith

Abstract

The foliation developed in parts of the Bega Batholith is related to the mode of granite emplacement and the regional tectonic setting. In the Cape Conran area in Victoria, folding and metamorphism coincide with the intrusion of the granite. During emplacement and cooling, a primary homogeneous syntectonic foliation (S) was developed and deformed by ductile shear bands (C), the S C fabric suggesting a minimum easterly displacement of approximately 3 km within the granite body. Quartz c‐axis fabrics in the granite define girdle patterns lying at high angles to an eastward shear direction and these are characteristic of a subsolidus deformation in the granite. These observations are compatible with plutonism during east‐west compression in an eastward shear regime. Similar examples in east Gippsland suggest that eastward shearing was a characteristic kinematic element of this part of the Lachlan Fold Belt during the late Middle Devonian.