@article{OgasawaraFukuyamaHorieetal.2013,
  author    = {Ogasawara, Masatsugu and Fukuyama, Mayuko and Horie, Kenji and Sumii, Tomoaki and Takehara, Mami and Sudo, Masafumi},
  title     = {SHRIMP U-Pb age of SoriZ93 zircon from the Sori Granodiorite, Northeast Japan: a potential reference zircon of Late Cretaceous age},
  series = {ISLAND ARC},
  volume    = {22},
  journal   = {ISLAND ARC},
  number    = {3},
  publisher = {WILEY-BLACKWELL},
  address   = {HOBOKEN},
  issn      = {1038-4871},
  doi       = {10.1111/iar.12041},
  pages     = {306 -- 317},
  year      = {2013},
  abstract  = {SoriZ93 zircon was separated from residual mineral fraction after the preparation of the SORI93 biotite standard from the Sori Granodiorite in the Ashio Mountains, Northeast Japan, and analyzed for its U-Pb age using a sensitive high resolution ion microprobe (SHRIMP). The zircon grains of SoriZ93 are prismatic with pyramidal ends or broken prismatic fragments. Most zircons are 100-250m long and 50-150m wide. The zircons are clear crystals and colorless to pale yellow, although some grains are brown with optically low transparency. Cathodoluminescence (CL) imaging of the SoriZ93 zircons showed a fine oscillatory zoning, which is a typical characteristic of zircons in granitic rocks. A xenocrystic core was not present in the zircons. Although some mineral inclusions were present in the zircons, it is possible to select a typical analytical area with a dimension of 30m necessary for the microbeam technique. The analytical results of the colorless zircons provided a weighted mean Pb-207 corrected Pb-206/U-238 age of 93.9 +/- 0.6Ma (95\% confidence, MSWD=0.97). This Pb-206/U-238 age is 1.3m.y. older than the K-Ar age of the SORI93 biotite, indicating that the granodiorite cooled to a closure temperature of the K-Ar biotite system within a short time interval. Although some grains of the SoriZ93 zircons show high U concentration, a selection of colorless zircons provided the precise age to be used for the calibration and reference for zircons of the Late Cretaceous.},
  language  = {en}
}