A New Natural Secondary Reference Material for Garnet U-Pb Dating by TIMS and LA-ICP-MS

AYSAL N., Guillong M., Bayanova T., Fukuyama M., Leonard N., YILMAZ İ., ...Daha Fazla

Geostandards and Geoanalytical Research, cilt.47, sa.2, ss.297-310, 2023 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 47 Sayı: 2
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1111/ggr.12493
  • Dergi Adı: Geostandards and Geoanalytical Research
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), Compendex, INSPEC, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.297-310
  • Anahtar Kelimeler: garnet dating, ID-TIMS, LA-ICP-MS, reference material, skarn zone
  • Ankara Üniversitesi Adresli: Evet

Özet

Gem quality andradite-rich garnet (IUC-1), obtained from the Miocene trachyte dome near Ankara city (Turkey), has been identified as a potential natural secondary reference material for U-Pb dating. In this study, U-Pb dating was performed in five different laboratories using isotope dilution TIMS and laser ablation ICP-MS to determine the homogeneity of euhedral garnet crystals. The U-Pb ID-TIMS data for IUC-1 yielded 207Pb/235U and 206Pb/238U ages of 20.9 ± 0.4 and 20.6 ± 0.8 Ma respectively, and these values are consistent with U-Pb LA-ICP-MS analyses, in which different garnet crystals yielded ages of 20.8 ± 0.1, 20.7 ± 0.1, 20.7 ± 0.2 and 20.2 ± 0.1 Ma. An andradite (IUC-2) from the Serçeören wollastonite skarn (Turkey) can be used as a secondary reference material provided detailed imaging of the crystals is undertaken. ID-TIMS data yielded 207Pb/235U and 206Pb/238U ages of 20.4 ± 0.4 and 20.9 ± 1.0 Ma respectively, and yielded U-Pb ages on different grains of 20.5 ± 0.1, 20.7 ± 1.0, 20.8 ± 1.7 and 20.9 ± 1.6 Ma. The assigned weighted mean age of IUC-1 (20.4 ± 0.5 Ma, 2s) is proposed as a 2023 reference value. IUC-1 garnet is expected to contribute significantly to rapidly developing garnet geochronology in the near future.