Relationship between shear zones and igneous activity: the Closepet granite of southern India

Abstract

The late Archaean Closepet granite of southern India is bounded by N-S trending shear zone. At the southern end of the granite both charnockite and granite veins are spatially associated with ductile shears. These shears continue further north and are confined to the contact zones in the central part of the granite outcrop. The main component of the shear zone are highly deformed granite sheets, augen gneisses and mylonites. Field observations and microstructural fabric of mylonites indicate a dextral sense of shear movement. Field evidence suggests that shear deformation was active throughout the evolution of the Closepet granite.