【摘要】 栖霞金矿集区位于胶东半岛中部,是胶东金矿集中区的重要组成部分,其成因是否与花岗岩有关存在不同的认识。栖霞金矿集区花岗岩体LA-ICP-MS锆石U-Pb年龄分析结果表明,其年龄为122～118 Ma,与金矿成矿年龄基本一致,暗示金矿与花岗岩可能存在成因联系。花岗岩SiO₂含量为65%～70%, Na₂O/K₂O=0.96～1.27,多数样品大于1.0; Na₂O+K₂O值为7.48%～8.06%,铝指数A/CNK=0.90～1.0,属于高钾钙碱性准铝质Ⅰ型花岗岩;这些花岗岩以高Sr（Sr>600μg/g）、低Y和Yb（Y<13μg/g, Yb<1.1μg/g）、相对亏损高场强元素（如Nb、Ta、Zr和Hf）及轻重稀土元素分馏强烈（（La/Yb）N=32.86～53.24）为特征,与胶东地区郭家岭花岗闪长岩地球化学特征十分类似,均属于高钾钙碱性埃达克质岩石,可能是在华北克拉通破坏背景下,拆沉下地壳的镁铁质岩石部分熔融形成的。更多还原

【Abstract】 The Qixia gold concentration area located in the central part of the Jiaodong Peninsula is an important part of the Jiaodong gold province. The relationship between the gold mineralization and the granite magmatism in the region is still controversy. LA-ICP-MS zircon U-Pb dating of the granites in the Qixia area yield ages of 122 to 118 Ma. The ages of the granites are consistent with that of the gold mineralization, which suggests a genetic relationship between the gold mineralization and granites. The granites in the Qixia area have SiO₂ contents of 65% to 70%, Na₂O+K₂O contents of 7.48% to 8.06%, Na₂O/K₂O ratios of 0.96 to 1.27（mostly higher than 1.0）, aluminum index（A/CNK） of 0.9 to 1.0, therefore, the granites belong to high potassium calc-alkaline metaluminous I type granite. The granites are characterized by enrichment in Sr（Sr>600 μg/g）, depletion in Y（Y<13 μg/g）, Yb（Yb<1.1 μg/g） and high field strength elements（HSFE） such as Nb, Ta, Zr and Hf, and strong rare earth element fractionation（LaN/YbN=32.86 to 53.24）. These geochemical features and the Guojialing granodiorites in Jiaodong alike belong to high-K calc-alkaline adakite. It can be inferred that the granites in the Qixia area are possibly partial melts of the delaminated lower crustal mafic rocks under the tectonic regime of the destruction of the North China Craton.更多还原