大别超高压变质带榴辉岩中金红石SHRIMP原位U-Pb定年及其年代学意义  

In-situ SHRIMP U-Pb Dating of Rutiles in Eclogite from Dabie UHP Metamorphic Belt and Its Geochronological Significance

作　　者：侯晨阳 杨天水[1] 石玉若[2] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质科学院地质研究所北京离子探针中心,北京100037

出　　处：《地球科学与环境学报》2016年第3期334-340,共7页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(41173065);国土资源部公益性行业科研专项经费项目(201311116);中国地质科学院地质研究所基本科研业务费项目(J1403)

摘　　要：对大别超高压变质带榴辉岩中金红石进行了SHRIMP原位U-Pb定年,得到金红石U-Pb年龄为(219±4)Ma,与前人利用TIMS方法获得的金红石年龄结果在误差范围内是一致的,验证了金红石用于SHRIMP原位U-Pb定年的可行性。通过对比发现,不同赋存状态的金红石U-Pb年龄无明显差别。根据本次测得的年龄数据,结合前人的研究成果,金河桥榴辉岩中金红石的UPb年龄为冷却年龄,代表了大别超高压变质带构造折返阶段的时代。In-situ SHRIMP U-Pb dating of rutile in eclogite from Dabie ultra-high pressure（UHP）metamorphic belt was studied.The U-Pb age of rutile obtained is（219±4）Ma,consistent with the previous TIMS results of rutiles within the error range.This consistence points to the feasibility of in-situ SHRIMP U-Pb dating of rutile.The dating results indicate no obvious differences for the U-Pb ages of rutiles from different occurrences.Taking together with the previous dating results,it is suggested that the U-Pb age of rutile in Jinheqiao eclogite is the cooling age,representing the tectonic exhumation time of Dabie UHP metamorphic belt.

关 键 词：年代学 榴辉岩 金红石 SHRIMP U-Pb年龄 封闭温度 大别超高压变质带 

分 类 号：P597[天文地球—地球化学]