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

摘要:

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110~120Ma之间（早白垩世），其形成与华北克拉通岩石圈减薄有关。

Abstract:

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.