中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
首页 机构 成果 学者
  
  1. CAS IR Grid
  2. 地质与地球物理研究所
  3. 中国科学院地质与地球物理研究所
  4. 岩石圈演化国家重点实验室
Validation of clinopyroxene-garnet magnesium isotope geothermometer to constrain the peak metamorphic temperature in ultrahigh-temperature ultramafic-mafic granulites

文献类型：期刊论文

作者Gou, Long-Long2; Zhai, Ming-Guo1,2; Zhang, Cheng-Li2; George, P. M.2; Huang, Kang-Jun2; Xu, Xiao-Fei2; Lu, Jun-Sheng2; Zhao, Yan2; Ao, Wen-Hao2; Hu, Yu-Hua2
刊名AMERICAN MINERALOGIST
出版日期2022-09-27
卷号107期号:9页码:1697-1708
ISSN号0003-004X
关键词Clinopyroxene-garnet Mg isotope geothermometer Mg isotope fractionation garnet pyroxenites high-pressure mafic granulites
DOI10.2138/am-2022-8058
英文摘要Conventional Fe-Mg exchange geothermometers generally are not effective means to measure the peak metamorphic temperatures of granulites because of Fe-Mg diffusion during the re-equilibration during the exhumation and cooling. Therefore, it is essential to find alternative geothermometers. In this study, we investigated the magnitude of Mg isotope fractionation between the coexisting clinopyroxene and garnet in garnet pyroxenites and high-pressure mafic granulites from southern India. The clinopyroxene and garnet from the garnet pyroxenites have delta Mg-26 values of -0.04 to -0.07 parts per thousand, and -0.65 to -0.64 parts per thousand, respectively, with Delta Mg-26(Cpx-Grt) = delta Mg-26(Cpx) - delta Mg-26(Grt) = 0.62 and 0.57 parts per thousand. The delta Mg-26 values of the coexisting clinopyroxene and garnet in the high-pressure mafic granulites are 0.03 to 0.07 parts per thousand and -0.54 to -0.55 parts per thousand, respectively, with Delta Mg-26(Cpx-Grt) = 0.57 and 0.62 parts per thousand. The inter-mineral Mg isotope fractionations between the clinopyroxene and garnet of the garnet pyroxenites are similar to those of the high-pressure mafic granulites and more or less fall within the equilibrium fractionation lines at peak metamorphic temperatures. The measured peak temperatures for all four samples indicate equilibrium Mg isotope fractionations between the clinopyroxene and garnet. The clinopyroxene-garnet Mg isotope geothermometer of Li et al. (2016) yields temperatures of 994 +/- 60 degrees C and 1048 +/- 89 degrees C for the garnet pyroxenites, and 1048 +/- 89 degrees C and 994 +/- 65 degrees C for the high-pressure mafic granulites, which are slightly lower than those at both 10 and 12 kbar from the clinopyroxene-garnet Mg isotope thermometer of Huang et al. (2013). Compared with the peak metamorphic conditions from phase equilibrium modeling, the clinopyroxene-garnet Mg isotope thermometry yielded temperatures corresponding to the peak metamorphic conditions of the garnet pyroxenites and the high-pressure mafic granulites, whereas the conventional clinopyroxene-garnet Fe-Mg exchange thermometry yielded lower temperatures corresponding to the retrograde metamorphism. These results underscore the inter-mineral Fe-Mg exchange between clinopyroxene and garnet during the retrograde cooling of the ultrahigh temperature (>900 degrees C), which, however, did not disturb their Mg isotope fractionation equilibrium attained during the ultrahigh-temperature metamorphic condition. Therefore, we conclude that clinopyroxene-garnet Mg isotope thermometry, together with phase equilibrium modeling, is a valid tool to constrain the peak metamorphic temperature conditions even for ultramafic-mafic granulites that have undergone ultrahigh-temperature metamorphism.
WOS关键词U-PB GEOCHRONOLOGY ; INDIA IMPLICATIONS ; CRUSTAL EVOLUTION ; SILICATE MELTS ; KOLLI-MASSIF ; SALEM BLOCK ; FRACTIONATION ; MG ; HETEROGENEITY ; KIMBERLITE
资助项目National Natural Science Foundation of China[41890831] ; State Key Laboratory of Continental Dynamics[SKLCD-04]
WOS研究方向Geochemistry & Geophysics ; Mineralogy
语种英语
出版者MINERALOGICAL SOC AMER
WOS记录号WOS:000846936300004
资助机构National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics ; State Key Laboratory of Continental Dynamics
源URL[http://ir.iggcas.ac.cn/handle/132A11/108382]  
专题地质与地球物理研究所_岩石圈演化国家重点实验室
通讯作者Zhai, Ming-Guo
作者单位1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China
2.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Peoples R China
推荐引用方式
GB/T 7714		 Gou, Long-Long,Zhai, Ming-Guo,Zhang, Cheng-Li,et al. Validation of clinopyroxene-garnet magnesium isotope geothermometer to constrain the peak metamorphic temperature in ultrahigh-temperature ultramafic-mafic granulites[J]. AMERICAN MINERALOGIST,2022,107(9):1697-1708.
APA Gou, Long-Long.,Zhai, Ming-Guo.,Zhang, Cheng-Li.,George, P. M..,Huang, Kang-Jun.,...&Zhou, Feng.(2022).Validation of clinopyroxene-garnet magnesium isotope geothermometer to constrain the peak metamorphic temperature in ultrahigh-temperature ultramafic-mafic granulites.AMERICAN MINERALOGIST,107(9),1697-1708.
MLA Gou, Long-Long,et al."Validation of clinopyroxene-garnet magnesium isotope geothermometer to constrain the peak metamorphic temperature in ultrahigh-temperature ultramafic-mafic granulites".AMERICAN MINERALOGIST 107.9(2022):1697-1708.

入库方式： OAI收割

来源：地质与地球物理研究所

浏览0
下载0
收藏0
其他版本

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。