1991•Journal of Mineralogical and Petrological SciencesRequires access
K-Ar dating on felsic igneous rocks along the Kamiyakawa-Ikegawa Tectonic Line.
Naomichi Umehara, Tetsumaru Itaya, Shin-ichi Yoshikura
Open publisher page 0 citations
Abstract
K-Ar dating was carried out on the Yanagino dacite and Takaiwa rhyolite which form part of a roughly E-W chain of small felsic intrusions along the Kamiyakawa-Ikegawa tectonic line in central Shikoku. K-Ar whole rock ages of the Yanagino dacite range from 15.2 ± 0.4 Ma to 16.9 ± 0.4 Ma and its biotite yields a little younger age of 14.2 ± 0.4 Ma. A K-Ar whole rock age of 15.0 ± 0.5 Ma was determined for the Takaiwa rhyolite. Present study confirms the felsic intrusions are correlated in age with the Miocene Ishizuchi Group and related intrusions distributed to the north of the tectonic line.