河北窟窿山碱性花岗岩形成的构造环境及侵位机制

本文根据窟窿山碱性花岗岩的岩石化学成分和特征指数、微量元素及区域构造的综合分析，认为它属于大陆内部拉张构造环境中，非造山期的Ａ型花岗岩。其产出位置恰好在上黄旗－乌龙沟深断裂带内，一些ＮＥ走向张性断裂发育，该区早期破火山口的塌陷作用，为碱性花岗岩的侵入提供了有利的空间条件，并具有被动侵位的特点。从已测得Ｋ－Ａｒ法年龄值（１０８Ｍａ），推断其侵位时代上限为早白垩纪晚期。

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.