Accurate U‐Pb Age and Trace Element Determinations of Zircon by Laser Ablation‐Inductively Coupled Plasma‐Mass Spectrometry

Geostandards and Geoanalytical Research - Tập 28 Số 3 - Trang 353-370 - 2004
Honglin Yuan1,2, Shan Gao3,1, Xiaoming Liu1, Huiming Li4, Detlef Günther5, Fu‐Yuan Wu6
1Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xian 710069, China
2Laboratory of Inorganic Chemistry, ETH Hönggerberg, CH-8093 Zürich, Switzerland
3Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China
4Tianjin Institute of Geology and Mineral Resources, Chinese Academy of Sciences, Tianjing 300170, China
5Laboratory of Inorganic Chemistry, ETH‐Hönggerberg, CH‐8093, Zürich, Switzerland
6Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

Tóm tắt

Various zircons of Proterozoic to Oligocene ages (1060‐31 Ma) were analysed by laser ablation‐inductively coupled plasma‐mass spectrometry. Calibration was performed using Harvard reference zircon 91500 or Australian National University reference zircon TEMORA 1 as external calibrant. The results agree with those obtained by SIMS within 2s error. Twenty‐four trace and rare earth elements (P, Ti, Cr, Y, Nb, fourteen REE, Hf, Ta, Pb, Th and U) were analysed on four fragments of zircon 91500. NIST SRM 610 was used as the reference material and 29Si was used as internal calibrant. Based on determinations of four fragments, this zircon shows significant intra‐and inter‐fragment variations in the range from 10% to 85% on a scale of 120 μm, with the variation of REE concentrations up to 38.7%, although the chondrite‐normalised REE distributions are very similar. In contrast, the determined age values for zircon 91500 agree with TIMS data and are homogeneous within 8.7 Ma (2s). A two‐stage ablation strategy was developed for optimising U‐Pb age determinations with satisfactory trace element and REE results. The first cycle of ablation was used to collect data for age determination only, which was followed by continuous ablation on the same spot to determine REE and trace element concentrations. Based on this procedure, it was possible to measure zircon ages as low as 30.37 0.39 Ma (MSWD = 1.4; 2s). Other examples for older zircons are also given.

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Tài liệu tham khảo

10.1016/S0012-821X(01)00406-X

10.1016/S0009-2541(02)00195-X

10.1130/0091-7613(2001)029<0383:TAOPIR>2.0.CO;2

10.1039/b203028b

10.1046/j.1440-0952.2001.485894.x

10.1007/s00410-002-0364-7

10.1016/S0009-2541(03)00165-7

10.1016/S0009-2541(00)00233-3

10.1039/a901765h

EgginsS.M. KinsleyL.P.J.andShelleyJ.M.G.(1998)Deposition and element fractionation processes during atmospheric pressure laser sampling for analysis by ICP‐MS. Applied Surface Science 127–129 278–286.

Fryer B.J., 1995, The design, operation and role of the laser ablation microprobe coupled with an inductively coupled plasma‐mass spectrometer LAM‐ICP‐MS in the Earth sciences, Canadian Mineralogist Journal, 33, 303

10.1111/j.1751-908X.2002.tb00886.x

10.1039/B202988J

10.1007/s00216-001-1148-z

10.1039/a901648a

10.1039/a701423f

10.1016/S0584-8547(99)00011-7

10.1016/S0009-2541(02)00058-X

10.1016/0016-7037(95)00144-1

Horn I., 2000, Precise elemental and isotope ratio determination by simultaneous solution nebulization and laser ablation‐ICP‐MS: Application to U‐Pb geochronology, Chemical Geology, 167, 405

Hoskin P.W.O., 1998, Minor and trace element analysis of natural zircon (ZrSiO4) by SIMS and laser ablation ICP‐MS: A consideration and comparison of two broadly competitive techniques, Journal of Trace and Microprobe Techniques, 16, 301

JaffeyA.H. FlynnK.F. GlendeninL.E. BentleyW.C. EsslingA.M.(1971)Precision measurement of half‐lives and specific activities of235U and238U. Physical Review C 4 1889–1906.

10.1016/S0009-2541(01)00341-2

10.1038/36554

10.1016/S0009-2541(00)00394-6

10.1039/JA9961100899

10.1007/s0021663550538

Ludwig K.R., 2003, ISOPLOT 3: A geochronological toolkit for microsoft excel, Berkeley Geochronology Centre Special Publication, 4, 74

10.1039/a903304a

10.1111/j.1751-908X.1997.tb00538.x

10.1016/S0009-2541(01)00355-2

10.1016/S0039-9140(02)00053-X

10.1007/s00410-002-0432-z

10.1111/j.1751-908X.1995.tb00147.x

10.1007/BF02900661