@article{oai:nagoya.repo.nii.ac.jp:00001403,
 author = {Suzuki, Kazuhiro and Adachi, Mamoru},
 journal = {The Journal of earth and planetary sciences, Nagoya University},
 month = {Dec},
 note = {CHIME (chemical Th-U-total Pb isochron) ages were determined on monazite and zircon from three samples (Nos. 0708A, 0708B and 0709) of the Hirasawa granitic mass (Hirasawa Mass) in the South Kitakami terrane, Northeast Japan. The CHIME monazite ages are 240±20 Ma for sample 0708A, 240±10 Ma for sample 0708B and 240±10 Ma for sample 0709. Zircon from sample 0708A gives a CHIME age of 240±20 Ma. These age data indicate the late Permian to early Triassic emplacement of the Hirasawa Mass. Rocks of the Hirasawa Mass are coarse-grained peraluminous biotite adamellite, having ca. 74% SiO_2,0.22% TiO_2,13.8% Al_2O_3,1.9% total Fe as FeO, 0.6% MgO, 1.5% CaO, 3.5% Na_2O and 4% K_2O. They are generally similar to other late Permian to early Triassic peraluminous granitoids in the South Kitakami terrane, but are discriminated from the 250-260 Ma leucocratic adamellite at Kusayami-zawa in higher CaO/(Na_2O+K_2O) ratios and from the 240-250 Ma leucogranite of the Okuhinotsuchi Mass in lower K_2O/Na_2O ratios and higher TiO_2 contents. The late Permian to early Triassic plutonism in the South Kitakami terrane, which was much extensive and diverse, corresponds to the major tectonic event between Permian and Triassic periods., 国立情報学研究所で電子化したコンテンツを使用している。},
 pages = {1--16},
 title = {240 Ma CHIME Ages of Monazite and Zircon from the Hirasawa Granitic Mass in the South Kitakami Terrane},
 volume = {40},
 year = {1993}
}