中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Metamorphism, P-T path and zircon U-Pb dating of Paleoproterozoic mafic and felsic granulites from the Kongling terrane, South China

文献类型:期刊论文

作者Liu, Bo1,3; Zhai, Ming-Guo1,2; Zhao, Lei3; Cui, Xia-Hong4
刊名PRECAMBRIAN RESEARCH
出版日期2019-10-01
卷号333页码:18
关键词Kongling terrane similar to 2.0 Ga metamorphic event Mafic granulite Felsic granulite P-T path
ISSN号0301-9268
DOI10.1016/j.precamres.2019.105403
英文摘要The Kongling terrane, the best Archean outcrops exposed in South China, is considered as an ideal target to reveal the crustal formation and evolution of the Yangeze Block in Precambrian. Since the ancient Archean zircon was reported, considerable studies on geochronology have been conducted. Except for the Archean magmatic events, Paleoproterozoic metamorphism in the Kongling terrane is also widespread. In this study, metamorphism in Paleoproterozoic is primarily investigated compared with previous studies. The studies on metamorphism and zircon U-Pb geochronology of four mafic granulite samples and one felsic granulite sample in the Kongling terrane were conducted. Multi-stage metamorphism is recognized through petrographic observation. In the mafic rocks, the mineral assemblage of peak metamorphic stage is represented by garnet + orthopyroxene + clinopyroxene + plagioclase + quartz, and the retrograde stage is represented by the coronas of orthopyroxene + plagioclase + hornblende and orthopyroxene + plagioclase around garnet. The P-T conditions of the two stages obtained from two samples of them are at 811-853 degrees C, similar to 11 kbar; 700-728 degrees C, 5.1-6.0 kbar and 837-869 degrees C, similar to 11 kbar, 749-764 degrees C, 4.5-5.6 kbar, respectively. The calculated P-T conditions reveal that the mafic rocks underwent a stage of granulite facies metamorphism and a subsequent stage of high-amphibolite to low-granulite facies retrograde metamorphism, which defines a near isothermal decompression P-T path and may be associated to a continental collision process. Metamorphic zircons from mafic granulite rocks have weighted mean Pb-207/Pb-206 ages of similar to 2.0 Ga. These suggest that the terrane may be influenced by the assemblage of the Paleoproterozoic Nuna Supercontinent. Besides, felsic granulite is recognized in this study, and studies on its metamorphism and geochronology are conducted for the first time. The mineral assemblages of the peak and retrograde metamorphic stage are garnet + orthopyroxene + plagioclase + quartz and symplectite of orthopyroxene + cordierite surrounding garnet, respectively. The peak P-T conditions are at 875-936 degrees C, 8.3-10.4 kbar. The weighted mean Pb-207/Pb-206 age of this felsic granulite is also at similar to 2.0 Ga. Moreover, a period of magmatic event is recorded in this sample, which have a weighted mean Pb-207/Pb-206 age of 2945 +/- 18 Ma, corresponding to the widespread magmatism generating rocks at 2.9 Ga in the Kongling terrane. The Kongling terrane used to be thought of lacking orthopyroxene in both of the meta-felsic and metasedimentary rocks. But because of the high weathering rate in this area, good observations were not achieved in the field, so the geological implication of the felsic granulite also requires further studies.
WOS关键词NORTHERN YANGTZE CRATON ; GA CONTINENTAL-CRUST ; HF ISOTOPE ; TRACE-ELEMENT ; IGNEOUS ROCKS ; AGE ; EVOLUTION ; COMPLEX ; GARNET ; GROWTH
资助项目National Natural Science Foundation of China[41530208]
WOS研究方向Geology
语种英语
WOS记录号WOS:000493218900007
出版者ELSEVIER
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 ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China
源URL[http://ir.iggcas.ac.cn/handle/132A11/95756]  
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.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
2.Univ Chinese Acad Sci, Key Lab Computat Geodynam, Beijing 100049, Peoples R China
3.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
4.Hebei GEO Univ, Shijiazhuang 050031, Hebei, Peoples R China
推荐引用方式
GB/T 7714
Liu, Bo,Zhai, Ming-Guo,Zhao, Lei,et al. Metamorphism, P-T path and zircon U-Pb dating of Paleoproterozoic mafic and felsic granulites from the Kongling terrane, South China[J]. PRECAMBRIAN RESEARCH,2019,333:18.
APA Liu, Bo,Zhai, Ming-Guo,Zhao, Lei,&Cui, Xia-Hong.(2019).Metamorphism, P-T path and zircon U-Pb dating of Paleoproterozoic mafic and felsic granulites from the Kongling terrane, South China.PRECAMBRIAN RESEARCH,333,18.
MLA Liu, Bo,et al."Metamorphism, P-T path and zircon U-Pb dating of Paleoproterozoic mafic and felsic granulites from the Kongling terrane, South China".PRECAMBRIAN RESEARCH 333(2019):18.

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来源:地质与地球物理研究所

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