日高山脈北部の日勝峠花こう岩体のＲｂ‐Ｓｒ全岩アイソクロン年代 [in Japanese] Rb-Sr whole-rock isochron age of the Nissho Toge granite complex, northern Hidaka Mountains, central Hokkaido, Japan [in Japanese]
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We obtained a Rb-Sr whole-rock isochron age of 17.7±0.6 Ma from the Nissho Toge granite complex, which intruded the upper portion of a ∼20-km-thick crustal section exposed in the northern Hidaka Mountains, central Hokkaido, Japan. The initial <sup>87</sup>Sr/<sup>86</sup>Sr ratio is 0.70422±0.00009. This age is similar to U-Pb zircon ages reported previously for the Pankenushi gabbro and Magarisawa tonalite (18.5±0.3 Ma and 18.7±0.5 Ma, respectively), which are both located in the lower portion of the crustal section examined in the present study. Our result suggests that almost all of the magmatic bodies in the crustal section were emplaced contemporaneously, during the Early Miocene.
- The Journal of the Geological Society of Japan
The Journal of the Geological Society of Japan 117(1), 57-60, 2011
The Geological Society of Japan