Crystallisation of Ca-bearing nepheline in basanites from Kajishiyama, Tsuyama Basin, Southwest Japan

Abstract

Ca-bearing nepheline found in the Kajishiyama basanite, Tsuyama Basin, southwest Japan, was investigated to clarify its genesis in silica-undersaturated magmas. The Kajishiyama basanite contains olivine and augite as phenocrysts and microphenocrysts, and Ca-bearing nepheline, olivine, augite, ulvöspinel, plagioclase, alkali feldspar, apatite and zeolites in the groundmass.