Sr-Nd-Pb isotopic and bulk rock chemical compositions of Wakurayama dacite from the Matsue city, southwest Japan

Abstract

Late Miocene to Pliocene Wakurayama dacite is distributed within a 5km radius in Matsue city, Sanin district, southwest Japan. We clarified the Bulk rock chemical compositions and Sr-Nd-Pb isotopic ratios of Wakurayma dacite. It has been understood that the chemical compositions of all Wakurayama dacite is extremely similar to the adakite. And it is also similar to chemical compositions of Quaternary Daisen volcano of Sanin district. In addition, a lot of Quaternary adakitic rocks are reported to the Sanin district. It may be explained that the adakitic magma source is exist in the Subducted Philippine Sea plate, and Wakurayama dacite might have been a beginning activity of adakite at 5Ma in the Sanin district.