Structural pattern and intrusion mechanism of the Banshanpu massif in eastern Hunan

The Banshanpu intrusive in eastern Hunan is an oral granite body, 21.3 km in length and 17.8 km in width, with a sharp contact with its wall rocks. On the basis the structural characteristics of its main units and wall rocks and from the strain and magnetic fabric analyses of rock, it is suggested that the intrusion of the Banshanpu granite massif involved several stages, that is, production of remelting magma, diapiric uprise, pulsating upwelling, anticlockwide totation and balloon type expansion.