(1. 中南大学 有色金属成矿预测教育部重点实验室，长沙 410083；
2. 中南大学 地球科学与信息物理学院，长沙 410083；3. 湖南省有色地质勘查局一总队，郴州 423000；
4. 湖南省有色地质勘查局，长沙 410007)
摘 要: 新生矿区花岗岩体岩性为黑云母花岗岩和黑云母二长花岗岩。花岗岩总体上具有富钾、高硅的特征，为钙碱性到弱过铝质花岗岩的过渡(A/CNK为0.93~1.13)。花岗岩具有强烈的Eu负异常(δEu为0.15~0.35)，稀土元素配分曲线呈不对称的“海鸥型”，与典型过铝质A型花岗岩的特征一致。花岗岩的10 000Ga/Al为3.62(3.47~4.00)，与世界A型花岗岩平均值3.75相接近。锆石U-Pb年龄为(147.5±3.5) Ma(MSWD=2.6)，显示岩体形成于燕山早期第二阶段。锆石的εHf(t)为-5.79~-4.15，暗示岩浆来源于均一源区，锆石的Hf同位素两阶段模式年龄(TDM2)为1.208~1.290 Ga，平均为1.227 Ga，说明岩浆源区有中元古代的古老地壳物质的加入。花岗岩构造环境判别图解显示为造山后(A2)的板内花岗岩。成矿花岗岩是在燕山早期晚阶段板内拉张背景下侵入地壳，并带来成矿物质形成矽卡型铜多金属矿床。
关键字: 铜多金属矿床；A型花岗岩；锆石U-Pb定年；Hf同位素
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals
Ministry of Education, Central South University, Changsha 410083, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
3. First General Geological Team of Hunan Nonferrous Metal Geo-exploration Bureau, Chenzhou 423000, China;
4. Hunan Nonferrous Metal Geo-exploration Bureau, Changsha 410007, China）
Abstract:The Xinsheng granite bodies are distinguished as biotite granite and biotite monzogranite in mining area, the granites can be classified to be calc-alkaline granite and weakly peraluminous granite with K-rich, Si-high (the values of A/CNK are 0.93-1.13). The granites have obvious Eu negative anomaly, the REE distribution patterns be long to the type of “gull”, which are the same as that of typical A-type granite. The average value of 10 000Ga/Al of granites is 3.62 (3.47-4.00), which is close to 3.75, the average value of A-type granite worldwide. The zircon U-Pb age of granite bodies is (147.5±3.5) Ma (MSWD=2.6), which shows that they formed in the second stage of early Yanshan movement. The values of εHf(t) are -5.79- -4.15, indicating that the magma mainly derived from a uniform resource. The model ages of two-stage range of zircon Hf isotope (TDM2) are 1.208-1.290 Ga (average value is 1.227 Ga). This feature indicates that the granite bodies originated from melting of early crustal materials formed in mesoproterozoic. The discrimination diagrams for tectonic background of granites prove that the granites formed in intra-plate extension environment, and the granites are A2-type, so, the granite body intrusived to lower crust in extension environment, and brought enough mineralizing material to form skarn type copper polymetallic deposit.
Key words: copper polymetallic deposit; A-type granite; zircon U-Pb dating; Hf isotope
