(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. 河南省有色金属矿产探测工程技术研究中心，郑州 450016；
4. 河南省有色金属地质勘查总院，郑州 450052)
摘 要: 姚冲斑岩型钼矿床位于东秦岭-大别山钼成矿带，矿体产于花岗岩外接触带大别片麻杂岩中。矿体下部的隐伏岩体岩性主要为二长花岗岩和花岗斑岩。LA-ICP-MS锆石U-Pb定年结果表明：二长花岗岩和花岗斑岩的侵位年龄分别为(139.6±2.0) Ma和(139.8±2.2) Ma，形成于晚侏罗世-早白垩世。锆石Hf同位素分析结果表明：姚冲钼矿区花岗岩的εHf(t)值范围为-30~-22.8，位于地幔演化线之下，tDM2值范围为2.21~2.60 Ga，表明其源于扬子板块北缘的古老地壳，其组成类似于扬子板块北缘TTG型岩浆岩。姚冲钼矿床形成于晚侏罗世-早白垩世构造体制从挤压收缩向区域性伸展的大转换阶段，扬子板块拆沉作用导致软流圈上涌，诱发加厚下地壳部分熔融产生的花岗质岩浆，为姚冲钼矿床成岩成矿作用提供了物质来源。
关键字: 大别山；姚冲钼矿床；LA-ICP-MS锆石；U-Pb年龄；Hf同位素
（1. Key Laboratory of Nonferrous Metal Ore Forecast, Ministry of Education,
Central South University, Changsha 410083, China;
2. School of Geosciences and Info physics, Central South University, Changsha 410083, China;
3. Non-Ferrous Mineral Exploration Engineering Research Center of Henan Province, Zhengzhou 450016，China;
4. Henan Institute of Geological Exploration for Non-ferrous Metal, Zhengzhou 450052, China）
Abstract:Yaochong Mo deposit is located at Qinling-Dabie metallogenic belt, the deposit is produced in Dabie metamorphic complex at the exocontact zone. Yaochong concealed stock consists of the monzogranite and granite porphyry, which yield LA-ICP-MS zircon U-Pb ages (139.6±2.0) Ma and (139.8±2.2) Ma, respectively, indicating that Yaochong granite was formed at the Late Jurassic-Early Cretaceous magmatism. According to zircon Hf isotope analyses, the εHf(t) values of the granite range from -30 to -22.8, which is located below the depleted mantle line. The tDM2 values range from 2.21 Ga to 2.60 Ga, which indicates the granite was formed from the lower crust of Yangtze Block. The component of the granite porphyry is similar to Neoproterozoic TTG magmatic rocks. The mineralization of Yaochong Mo deposit was formed in the Late Jurassic-Early Cretaceous period of the transformation of tectonic regime. The granitic magma was derived from the patial melting of ancient crust triggered by asthenosphere upwelling, which probably provides diagenesis and ore-forming material of Yaochong Mo deposit.
Key words: Northern Dabie Mountain; Yaochong Mo deposit; LA-ICP-MS zircon; U-Pb age; Hf isotope
