THERMODYNAMIC STRUCTURES AND EMPLACEMENT MECHANISM OF THE ZHOUKOUDIAN INTRUSION

The Zhoukoudian intrusion is a composite stock character ized by two intrusive activities. Studies of the structures of the country rocks concordant with the intrusion, flow structure of the intrusion, measurements of the strain of the xenoliths, features of the strong deformation zone on the northwestern margin of the intrusion and minor ductile shear zoaes indicate that the Zhoukoudian intrusion is a typical body resulting from oblique diapiric intrusion and with a ballooning-like model. The "gneissic structure" in the strong deformation zone on the northwestern margin of the intrusion is compression schisto sity （s） formed by magmatic pulsation rather than primary flow structure. Shear schistosity （c） in the minor ductile shear zone in the northwestern part of the intrusion was formed later than compression schistosity （s）. These conclusions have been verified by the fabric analysis of quartz in the ductile shear zone.