Ductile and brittle deformation in the Cann Valley Granitoids, Victoria

Foliated portions of the Early Devonian Bega Batholith were developed in an apparent flattening field contemporaneous with their plutonic emplacement. Overprinting the foliated portions of the granites are a series of Early‐Middle Devonian ductile shear zones characterized by mylonitic rocks with dextral horizontal movement. The principal shortening during the ductile shear zone development has a trend of 140°. Brittle deformation, confined to narrow gouge and microbreccia zones, is superimposed on the features of ductile deformation. The brittle features represent deformation at higher crustal levels with the orientation of the principal shortening becoming almost north‐south.