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在占我国最著名的金矿域─胶北金矿域的金矿储量86．3％的招掖金矿带内，广泛分布的燕山期花岗岩类与金矿化作用密切相关。然而，这些花岗岩类的形成时代却是长期困扰地学界的棘手问题，并一直阻碍着有关金矿化问题的探讨。精确的单颗粒钻石U－Pb年代学研究表明，招掖金矿带内花岗岩类：玲珑型花岗岩和郭家岭花岗闪长岩均形成于145Ma（分别为145．9±05Ma和144．1±0．8Ma）左右的燕山早期（晚侏罗世）。其中存在年龄为2.7Ga左右的继承性锆石，这显示了这些花岗岩类为壳源重熔的产物，而胶东岩群可能为其重要源岩之一。综合已有资料分析，该区与花岗岩类有关的金矿化作用可能发生于100～120Ma区间内。
The widespread Yanshanian granitoids are closely related to the gold mineralization in the Zhaoyu gold belt, which accounts for 86.3% of the gold deposits in the Jiaobei Gold Mine, the most famous gold mine in our country. However, the age of formation of these granitoids has been a thorny issue that has plagued academics for a long time and has hindered the exploration of gold mineralization. The accurate monograin diamond U-Pb chronological study shows that the granitoids within the Zhaoyuan gold belt: extrusive granites and Guojialing granodiorites were formed at 145 Ma (145.9 ± 05 Ma and 144.1 ± 0 respectively .8Ma) Early Yanshanian (Late Jurassic). Among them, there are inherited zircons with an age of about 2.7Ga, indicating that these granites are the products of remelting of the crust, and that the Jiaodong Formation may be one of the important source rocks. According to the existing data analysis, the gold mineralization related to granitoids in this area may occur in the range of 100 ~ 120Ma.