Neodymium isotopic compositions of the standard monazites used in U-Th-Pb geochronology

doi:10.1016/j.chemgeo.2012.09.034

	Neodymium isotopic compositions of the standard monazites used in U-Th-Pb geochronology
	Liu, Zhi-Chao 1; Wu, Fu-Yuan 1; Yang, Yue-Heng 1; Yang, Jin-Hui 1; Wilde, Simon A.2
刊名	CHEMICAL GEOLOGY
	2012-12-12
卷号	334 页码:221-239
关键词	Monazite LA-(MC)-ICP-MS U-Th-Pb dating Sm-Nd isotopes
ISSN号	0009-2541
DOI	10.1016/j.chemgeo.2012.09.034
文献子类	Article
英文摘要	As an important carrier of thorium, uranium and trace elements, monazite is widely used in U-Th-Pb geochronology and Sm-Nd isotopic studies. The combination of U-Th-Pb age and Sm-Nd isotopic composition makes monazite one of the most versatile minerals in the study of crustal evolution. Nevertheless, most monazites are small and have complex internal textures that require isotopic measurements with high spatial resolution. The widely utilized in situ analyses, such as secondary ion mass spectrometry (SIMS) and inductively coupled plasma mass spectrometry (ICP-MS), have emphasized the importance for uniform and homogeneous monazite standards for external calibration. Here we performed in situ simultaneous measurement of U-Th-Pb and Sm-Nd isotopes, as well as trace element determinations, of several monazite standards using a 193 nm excimer laser ablation system coupled with an Agilent 7500a quadruple (Q)-ICP-MS and a Neptune multi-collector (MC)-ICP-MS. For U-Th-Pb isotopic analysis, instrumental mass bias and elemental fractionation were corrected by calibrating against a homogeneous monazite standard (44069), which makes it possible to precisely and accurately date other monazite grains. In terms of the Sm-Nd isotopes, the interference of Sm-144 on Nd-144 was corrected by using the interference-free Sm-147/Sm-149 for the Sm mass fractionation, and the fractionation between 144Sm and 144Nd was corrected by calibrating against an external monazite standard Manangoutry, which is homogeneous in Sm-Nd isotopic composition. The obtained Sm-Nd isotopic compositions for synthetic LREE glass and natural monazite samples are all consistent with the values obtained by isotope dilution thermal ionization mass spectrometry (ID-TIMS), which indicates the reliability and robustness of our method. Our results demonstrate that the Manangoutry monazite from Madagascar and the Namaqualand monazite from South Africa are relatively uniform and homogeneous in their Sm-Nd isotopic compositions, and hence can serve as standards for external calibration during in situ Sm-Nd isotopic analysis. (C) 2012 Elsevier B.V. All rights reserved.
WOS关键词	MC-ICP-MS ; IONIZATION MASS-SPECTROMETRY ; TRACE-ELEMENT ANALYSIS ; RARE-EARTH-ELEMENTS ; LASER-ABLATION ; ELECTRON-MICROPROBE ; ACCESSORY MINERALS ; ID-TIMS ; LU-HF ; ZIRCON
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000313306600019
资助机构	National Natural Science Foundation of China(41130313) ; National Natural Science Foundation of China(41130313) ; National Natural Science Foundation of China(41130313) ; National Natural Science Foundation of China(41130313) ; National Natural Science Foundation of China(41130313) ; National Natural Science Foundation of China(41130313) ; National Natural Science Foundation of China(41130313) ; National Natural Science Foundation of China(41130313)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/84596]
专题	中国科学院地质与地球物理研究所
通讯作者	Liu, Zhi-Chao
作者单位	1.Chinese Acad Sci, State Key Lab Lithospher Evolut, Inst Geol & Geophys, Beijing 100029, Peoples R China 2.Curtin Univ Technol, Dept Appl Geol, Perth, WA 6845, Australia
推荐引用方式 GB/T 7714	Liu, Zhi-Chao,Wu, Fu-Yuan,Yang, Yue-Heng,et al. Neodymium isotopic compositions of the standard monazites used in U-Th-Pb geochronology[J]. CHEMICAL GEOLOGY,2012,334:221-239.
APA	Liu, Zhi-Chao,Wu, Fu-Yuan,Yang, Yue-Heng,Yang, Jin-Hui,&Wilde, Simon A..(2012).Neodymium isotopic compositions of the standard monazites used in U-Th-Pb geochronology.CHEMICAL GEOLOGY,334,221-239.
MLA	Liu, Zhi-Chao,et al."Neodymium isotopic compositions of the standard monazites used in U-Th-Pb geochronology".CHEMICAL GEOLOGY 334(2012):221-239.