Sr and Nd isotopes on granitoids from eastern Inbi Intrusives, Inner Zone of Southwest Japan

Abstract

In the present study, whole-rock analyses, and Sr and Nd isotope analyses for granitoids (Ningyo Toge Granite, Tottori Granite, and Sangenya Granodiorite) from eastern Inbi Intrusives were carried out in order to discuss the plutonic magma history of the San-in Belt, Inner Zone of Southwest Japan. Whole-rock chemical characteristics categorize these granitoids as I-type. Rb-Sr isochron age for six samples of Ningyo Toge granites is given as 66.1 +/- 5.0 Ma (1 sigma). Relationship of epsilon NdI vs. epsilon SrI suggests that the parental magma of the Ningyo Toge Granite is probably not linked to that of the Tottori Granite.