中文摘要：

为探究南秦岭柞水-山阳矿集区内两期花岗岩体在岩石成因、成岩物质来源及成岩动力学背景方面的联系,对矿集区内燕山期几个代表性花岗岩体进行主微量元素、锆石U-Pb及Lu-Hf同位素地球化学研究。结果显示,两期岩体具有相似的地球化学特征,均为准铝质-过铝质钙碱性或高钾钙碱性Ⅰ型花岗岩;Sr-Nd-Pb-Hf数据表明两期岩体均为壳幔混合岩浆的产物,可能均以南秦岭基底耀岭河群变基性火山岩为岩浆主要源区;印支期岩体成岩年龄为197~246.8Ma,集中于210~230Ma,燕山期岩体形成于138.1~150.2Ma。印支期岩体形成于主造山期后伸展环境,因构造体制由挤压向伸展转换,引发强烈壳幔相互作用;燕山期岩体形成于晚侏罗世-早白垩世中国东部构造体制转换阶段,造山带处于伸展应力状态下,诱发岩石圈的拆沉减薄,软流圈抬升及强烈壳幔相互作用。

英文摘要：

In order to decode the relationships of petrogenesis,material sources and petrogenic geodynamic settings between the Indosinian and Yanshanian granites in the Zhashui-Shanyang ore cluster district in the Southern Qinling,a comparisonal study on the Indosinian and Yanshanian granites has been undertaken based on our analyzed major and trace elements,zircon U-Pb ages and Lu-Hf isotopes of seven representative Yanshanian granite bodies in the area. The results indicate that the Indosinian and Yanshanian granites have similar geochemical characteristics. They both belong to metaluminous-peraluminous calc-alkaline to high-K calc-alkaline Ⅰ-type granites. Zircon U-Pb ages of the Indosinian granites vary from 197 Ma to 246. 8 Ma（ mainly from 210 to 230 Ma）,while those of the Yanshanian granites vary from 138. 1 Ma to150. 2 Ma. Sr-Nd-Pb-Hf isotopic compositions suggest that both granites could be derived from a common mixed crustmantle source similar to that the Yaolinghe meta-basic volcanics of the South Qinling basement. It is believed that the Indosinian granites in the area were formed in a post-orogenic extensional environment due to the strong crust-mantle interaction caused by the transition,from compression to extension,of tectonic setting. However,the Yanshanian granites wereformed in the transition,from compression to extension,of tectonic regime of the Eastern China in a period from Late Jurassic to Early Cretaceous. The extension of the Qinling orogenic belt induced the delamination and thinning of lithosphere,the uplift of asthenosphere,and the strong crust-mantle interaction.