河北省赤城县温泉环斑花岗岩的地质特征及形成时代

温泉环斑花岗岩分布于河北省赤城县温泉一带,面积约50km2。在1:25万延庆县幅区域地质调查工作的基础上,笔者研究了该岩体的产出状况、侵入关系等地质特征。结合岩石学、地球化学及同位素年龄等证据,探讨了温泉环斑花岗岩的形成时代。研究表明,该岩体为富钾、过铝、高铁、低钙、低镁A型花岗岩,形成于中元古代,相当于长城纪大红峪期,与北京市密云县沙厂环斑花岗岩可以对比。同时也为华北板块基底的克拉通化时间及其在中元古代发生的裂解事件提供了岩石学及同位素年龄依据。

Geological features and age of the Wenquan Rapakivi granite, Chicheng County, Hebei

The Wenquan Rapakivi granite is distributed in the Wenquan area, Chicheng County, Hebei Province, covering an area of about 50 km2. Based on the regional geological survey of the 1:25000 Yanqing County Sheet, the authors studied the mode of occurrence and intrusive relationships of the Wenquan Rapakivi granite and discussed its age according to the petrological, geochemical and isotope age evidence. Study shows that the intrusion is A-type granite with higher contents of K, Al and Fe and lower contents of Ca and Mg. It was formed in the Mesoproterozoic, which is equivalent to the Dahongyu Stage of the Changchengian System and can be correlated with the Shachang Rapakivi granite, Miyun County, Beijing. In addition, the study also provides petrological and isotope age evidence for the study of the time of cratonization of the basement of the North China plate and event of its break-up during the Mesoproterozoic.