THE TECTONIC ENVIRONMENT OF FORMATION AND MECHANISM OF INTRUSION OF THE KULONGSHAN ALKALI GRANITE BODY IN HEBEI

According to the petrochemical features and trace element features of the Kulongshan alkaligranite body in Hebei, it is considered that this granite body is the product of fracture activity inthe intracontinental extensional tectonic environment. The process of emplacement of the granitebody has been studied from the tectonic setting, regional structure and volcanic structure. It is held that the granite body has the features of passive emplacement and the result of the combinedaction of regional tectonism, caldera engulfment and natural buoyancy of magma.