Micro inclusions in anorthite megacryst from Take-shima, Kagoshima Prefecture, Japan

Abstract

Anorthite megacrysts of about 1 cm in maximum diameter are found as phenocrystsin the basaltic lavas from Take-shima, Kagoshima Prefecture, Japan. The anorthite megacrysts show slight optical zoning. Zonal arrangement of the micro inclusions of opaque minerals and bubbles are common in the specimens. From Back-scattered electron images and qualitative analyses, four types of micro inclusions of opaque minerals can be recognized within the megacryst: (1) Fe bearing vesicular fragment, (2) Fe bearing solid platelet, (3) Fe bearing solid particle, and (4) Fe bearing particles with Cu and S rich part and cavities.