Please use this identifier to cite or link to this item: https://ir.swu.ac.th/jspui/handle/123456789/12712
ชื่อเรื่อง: GZ7 and GZ8 – Two Zircon Reference Materials for SIMS U-Pb Geochronology
ผู้แต่ง: Nasdala L.
Corfu F.
Schoene B.
Tapster S.R.
Wall C.J.
Schmitz M.D.
Ovtcharova M.
Schaltegger U.
Kennedy A.K.
Kronz A.
Reiners P.W.
Yang Y.-H.
Wu F.-Y.
Gain S.E.M.
Griffin W.L.
Szymanowski D.
Chanmuang N. C.
Ende M.
Valley J.W.
Spicuzza M.J.
Wanthanachaisaeng B.
Giester G.
Keywords: Binary alloys
Geochronology
Placers
Secondary ion mass spectrometry
Silicate minerals
Titanium alloys
Uncertainty analysis
Zircon
Decay constants
Geothermometry
Mass fraction
Placer deposits
Reference material
Structure-related
U-Pb geochronology
Weighted mean
Lead alloys
วันที่เผยแพร่: 2018
บทคัดย่อ: Here, we document a detailed characterisation of two zircon gemstones, GZ7 and GZ8. Both stones had the same mass at 19.2 carats (3.84 g) each; both came from placer deposits in the Ratnapura district, Sri Lanka. The U-Pb data are in both cases concordant within the uncertainties of decay constants and yield weighted mean 206Pb/238U ages (95% confidence uncertainty) of 530.26 Ma ± 0.05 Ma (GZ7) and 543.92 Ma ± 0.06 Ma (GZ8). Neither GZ7 nor GZ8 have been subjected to any gem enhancement by heating. Structure-related parameters correspond well with the calculated alpha doses of 1.48 × 1018 g−1 (GZ7) and 2.53 × 1018 g−1 (GZ8), respectively, and the (U-Th)/He ages of 438 Ma ± 3 Ma (2s) for GZ7 and 426 Ma ± 9 Ma (2s) for GZ8 are typical of unheated zircon from Sri Lanka. The mean U mass fractions are 680 μg g−1 (GZ7) and 1305 μg g−1 (GZ8). The two zircon samples are proposed as reference materials for SIMS (secondary ion mass spectrometry) U-Pb geochronology. In addition, GZ7 (Ti mass fractions 25.08 μg g−1 ± 0.18 μg g−1; 95% confidence uncertainty) may prove useful as reference material for Ti-in-zircon temperature estimates. © 2018 The Authors. Geostandards and Geoanalytical Research published by John Wiley & Sons Ltd on behalf of International Association of Geoanalysts
URI: https://ir.swu.ac.th/jspui/handle/123456789/12712
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054508859&doi=10.1111%2fggr.12239&partnerID=40&md5=5ca377b4d03c6c75b06a00efe26dea25
ISSN: 16394488
Appears in Collections:Scopus 1983-2021

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