中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Radiogenic Pb mobilization induced by shock metamorphism of zircons in the Apollo 72255 Civet Cat norite clast

文献类型:期刊论文

作者Zhang, Bidong4,5; Lin, Yangting2; Moser, Desmond E.5; Hao, Jialong2; Liu, Yu3; Zhang, Jianchao2; Barker, Ivan R.5; Li, Qiuli3; Shieh, Sean R.5; Bouvier, Audrey1,5
刊名GEOCHIMICA ET COSMOCHIMICA ACTA
出版日期2021-06-01
卷号302页码:175-192
关键词Zircon U-Pb SIMS Apollo Pb mobilization Shock metamorphism
ISSN号0016-7037
DOI10.1016/j.gca.2021.03.012
英文摘要In situ U-Pb radiometric dating of zircons is regarded as one of the most widely used and reliable methods to acquire geochronologic ages. However, it has been recently reported that radiogenic Pb (Pb*) mobilization within zircon may, in some cases, cause inaccurate age determinations with no geological significance. Such Pb* mobilization can be caused by deformation, a-coil damage, fluid-assisted annealing, and recrystallization. In this study, we report an investigation of Pb* mobilization in shock metamorphosed lunar zircons. NanoSIMS (nanoscale secondary ion mass spectrometry) and IMS 1280HR ion microprobe dating, EBSD (electron backscatter diffraction) and CL (cathodoluminescence) mapping, and scanning ion imaging (SII) were applied to micro-zircon grains from the Apollo 72255 Civet Cat norite clast. Based on the large number of grains with similarities in internal zoning, habit and trace element geochemistry, and host mineral context, the Civet Cat norite zircons are interpreted to be primary, igneous grains. The chronology obtained for three consecutive surfaces (at different depths) by NanoSIMS, SII, and IMS 1280HR, respectively, indicates that the radiogenic Pb distribution of the Civet Cat norite zircons is heterogeneous among different polished or sputtering surfaces. Forty-two NanoSIMS U-Pb ages (beam size of 5 mu m) are concordant on a Wetherill Concordia diagram, and their corresponding Pb-207/Pb-206 ages spread from 4015 Ma to 4459 Ma. More notably, the six oldest spots of the 42 define a concordant U-Pb age of 4460 +/- 31 Ma (2r, MSWD = 0.47, P = 0.92) and a weighted mean Pb-207/Pb-206 age of 4453 +/- 34 Ma (MSWD = 0.056, P = 0.998). These dates are among the oldest in the lunar highland rocks. However, the Pb-207/Pb-206 ages of repolished surfaces of these zircons by IMS 1280HR (beam size of 5 mu m) do not reproduce the NanoSIMS results (up to 300 Ma younger). The SII (spatial resolution of 2 mu m) confirms a heterogeneous distribution of radiogenic Pb within single grains. The EBSD mapping of these zircon grains shows that they have 3-20 degrees of cumulative lattice misorientation. It is proposed that shock-related deformation has facilitated Pb* migration after primordial crystallization. With currently available data, we cannot preclude the possibility that the large errors of the U-Pb ages obscure reverse discordance that would bias our oldest Pb-207/Pb-206 ages to older values. Conversely, our data could be explained by mixing of Pb-retention and Pb-loss nanodomains as seen in shocked terrestrial zircon such that U-Pb date of 4460 +/- 31 Ma approximates the norite formation. (C) 2021 Elsevier Ltd. All rights reserved.
WOS关键词METEORITE SAU 169 ; U-PB ; THERMAL HISTORY ; ATOM-PROBE ; JACK HILLS ; BOULDER-1 ; STATION-2 ; AGE ; ISOTOPE ; IMPACT
资助项目NSERC ; Government of Ontario Early Researcher Award ; UCLA under NASA[80NSSC19K1238]
WOS研究方向Geochemistry & Geophysics
语种英语
WOS记录号WOS:000645903700010
出版者PERGAMON-ELSEVIER SCIENCE LTD
资助机构NSERC ; NSERC ; Government of Ontario Early Researcher Award ; Government of Ontario Early Researcher Award ; UCLA under NASA ; UCLA under NASA ; NSERC ; NSERC ; Government of Ontario Early Researcher Award ; Government of Ontario Early Researcher Award ; UCLA under NASA ; UCLA under NASA ; NSERC ; NSERC ; Government of Ontario Early Researcher Award ; Government of Ontario Early Researcher Award ; UCLA under NASA ; UCLA under NASA ; NSERC ; NSERC ; Government of Ontario Early Researcher Award ; Government of Ontario Early Researcher Award ; UCLA under NASA ; UCLA under NASA
源URL[http://ir.iggcas.ac.cn/handle/132A11/101198]  
专题地质与地球物理研究所_中国科学院地球与行星物理重点实验室
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Zhang, Bidong
作者单位1.Univ Bayreuth, Bayer Geoinst, D-95447 Bayreuth, Germany
2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earth & Planetary Phys, Beijing 100029, Peoples R China
3.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China
4.Univ Calif Los Angeles, Dept Earth Planetary & Space Sci, Los Angeles, CA 90095 USA
5.Univ Western Ontario, Dept Earth Sci, London, ON N6A 5B7, Canada
推荐引用方式
GB/T 7714
Zhang, Bidong,Lin, Yangting,Moser, Desmond E.,et al. Radiogenic Pb mobilization induced by shock metamorphism of zircons in the Apollo 72255 Civet Cat norite clast[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2021,302:175-192.
APA Zhang, Bidong.,Lin, Yangting.,Moser, Desmond E..,Hao, Jialong.,Liu, Yu.,...&Bouvier, Audrey.(2021).Radiogenic Pb mobilization induced by shock metamorphism of zircons in the Apollo 72255 Civet Cat norite clast.GEOCHIMICA ET COSMOCHIMICA ACTA,302,175-192.
MLA Zhang, Bidong,et al."Radiogenic Pb mobilization induced by shock metamorphism of zircons in the Apollo 72255 Civet Cat norite clast".GEOCHIMICA ET COSMOCHIMICA ACTA 302(2021):175-192.

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来源:地质与地球物理研究所

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