山东崂山花岗岩形成时代——锆石SHRIMP U-Pb定年

Forming Ages of Granites in Laoshan Area of Shandong Province——Zircon SHRIMP U-Pb Dating

白垩纪崂山超单元花岗岩由二长花岗岩、正长花岗岩、碱长花岗岩类组成,自早到晚存在明显的富钾演化特征。根据新的SHRIMP U-Pb锆石定年结果,该超单元早期相浮山亚超单元的浮山二长花岗岩年龄为（120±2）Ma,晚期相崂顶亚超单元的崂山碱长花岗岩年龄为（114±2）Ma。所以,可把崂山超单元花岗岩时代限定在110～120 Ma之间（早白垩世）,其形成与华北克拉通岩石圈减薄有关。

Granites in Cretaceous Laoshan superunitis composed of monzogranite,syenite granite and alkali feldspar granite.It has obvious characteristics of K-rich evolution from the early to late period.According to new SHRIMP U-Pb zircon dating results,the age of Fushan monzogranite in Xiangfushan sub-superunit in early period of Laoshan superunit is（120±2） Ma,while the forming age of alkali feldspar in the late period of Laoshan superunit is（114±2） Ma.Thus,the forming age of granites in Laoshan superunit can be determined as 110～120Ma（early Cretaceous）.Its formation has close relation with lithospheric thinning of the north China craton.