変成作用における金平糖様鉱物の成長と流体移動速度

抄録

There appears common occurrence of flower like shape of garnet, albite, and quartz which is surrounded by the matrix minerals such as chlorite, micas, and amphiboles in the regional metamorphic rocks, and of dendritic grains of cordierite, garnet, staurolite and plagioclase in the contact metamorphic rocks of thermal aureole. The latter is probably due to the rapid growth under the high degree of supersaturation, but the former is surely derived from the growth instability as like as the formation of icicle and hail which is characterized by regular spikes. This type of grain shape appears in the Japanese classic sugar ball something like small cake called as Kompeito in Japan which has also the periodic spikes on the surface. In this talk, the author intends to call this type of flower like grain as the kompeito grain hereafter and discuss the fluid flux producing the kompeito growth of albite by means of Mullins-Sekerka instability at the replacement of albite after chlorite.