R2: Crystal structure, crystal chemistry, physical properties of minerals, crystal growth and applied mineralogy

[R2P-07] Mineralogical study on acicular magnetite exsolution in plagioclase

「発表賞エントリー」

*Ryo Sugaya¹, Masahiko Sato¹, Toshihiro Kogure¹ (1. Univ. Tokyo, Sci.)

Keywords:Magnetite exsolution, Plagioclase, Paleomagnetism, Biotite

Acicular magnetite exsolution in plagioclase has attracted paleomagnetism researchers because of its possibility of a good remanent carrier. Information of magnetic minerals such as formation temperature is essential in order to utilize them to paleomagnetism, but that of this magnetite is not well understood. In this study we observed the fine structure of the acicular magnetite in plagioclase from Duluth Complex by using SEM and TEM, and found that K-feldspar and biotite accompany the magnetite. The biotite is considered to be a reaction product of magnetite and K-feldspar.