Petrography revived: the science of rock texture
Petrographyの復権: 岩石組織学のすすめ

Masaaki OBATA
2007 Japanese Magazine of Mineralogical and Petrological Sciences  
Recent advances in petrologic studies on kelyphite and symplectite, the reaction textures in metamorphic rocks, are reviewed. Kelyphitization of garnet is a phase transition phenomenon accompanied by a long range material transfer between garnet and olivine crystals. The microstructure of kelyphite is mostly constructed at the reaction front via short range material transfer along the garnet crystal surfaces and by the topotaxial crystal growth of pyroxenes and spinel. The law of normality and
more » ... w of normality and the principle of constant volume of the kelyphitization are proposed. Structural similarities among the kelyphites, symplectites, pearlite (of Fe C alloy) and columnar joints, developed in basaltic lavas, are pointed out and discussed. In general discussions, I re define petrography as the science of rock texture and discuss in a more general context its relation to tectonics in solid earth sciences.
doi:10.2465/gkk.36.168 fatcat:qapnd6qquzfipcz2l5l6wallae