Magmatic evolution in the Northern Kita-Hakkoda

Abstract

In this study, we discuss the magma evolution process of calc-alkaline rocks from the Northern Kita-Hakkoda based on topographic analysis, geological survey, bulk rock chemical composition and petrography. Compositional trends of compatible elements of calc-alkaline series are liner on the Harker’s diagrams, in contrast with those tholeiitic series. Some calc-alkaline rocks contain disequilibrium mineral assemblages and disequilibrium textures in the phenocryst. From the chemical variation of trace elements and from the disequilibrium textures, we conclude that the calc-alkaline series magma were formed by magma mixing.