含榴花岗片麻岩 Lu-Hf 年代学初探 |
| |
引用本文: | 张超,程昊,J D Vervoort.含榴花岗片麻岩 Lu-Hf 年代学初探[J].地球化学,2012(4):371-379. |
| |
作者姓名: | 张超 程昊 J D Vervoort |
| |
作者单位: | 1. 同济大学海洋地质国家重点实验室,上海200092 2. School of Earth and Environmental Sciences, Washington State University, Washington 99164, USA |
| |
基金项目: | 国家自然科学基金(40973005);中央高校基本科研业务费专项资金 |
| |
摘 要: | 对西大别四道河含石榴子石花岗片麻岩进行了锆石 U-Pb 和石榴子石 Lu-Hf 年代学测试,锆石 U-Pb谐和年龄为(223±1) Ma,石榴子石-全岩 Lu-Hf 等时线年龄为(212.2±0.7) Ma.石榴子石具有极高的母子体同位素比值(176Lu/177Hf =~300).结合锆石和石榴子石的微量元素特征,该锆石 U-Pb 年龄代表的可能是超高压/高压变质时间,石榴子石 Lu-Hf 年龄代表的是石榴子石重结晶时间,可能指示了后期退变质作用流体活动
|
关 键 词: | Lu-Hf 石榴子石 花岗片麻岩 大别 |
Lu-Hf garnet geochronology of granitic gneiss from the West Dabie Mountains |
| |
Institution: | ZHANG Chao1, CHENG Hao1* and J D Vervoort21. State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China;3. School of Earth and Environmental Sciences, Washington State University, Washington 99164, USA |
| |
Abstract: | We dated a garnet-bearing granitic gneiss from the West Dabie Mountains using combined zircon U-Pb and garnet Lu-Hf isochron dating. A weighted-mean 206Pb/238U age of (223±1) Ma is older than the mineral-whole rock Lu-Hf isochron age of (212.2±0.7) Ma. The garnet fractions have extremely high parent/daughter ratios (176Lu/177Hf = ~300). Taking the trace element zoning patterns of both zircon and garnet into account, the zircon U-Pb age is, therefore, interpreted to reflect high-pressure eclogite-facies metamorphism while the Lu-Hf age records a later event of garnet recrystallization, likely indicating fluid activity during retrograde metamorphism. |
| |
Keywords: | Lu-Hf garnet granitic gneiss Dabie |
本文献已被 CNKI 维普 万方数据 等数据库收录! |
|