日本の隕石学  [in Japanese] Meteorite study in Japan  [in Japanese]

Meteorite studies in Japan made a great progress both quantitatively and qualitatively since about 1975 by the discovery of the Antarctic meteorites. Though meteorite study includes Petrology, mineralogy, geochemistry, and geophysics, petrological and mineralogical studies are reviewed in this paper. Detailed microprobe works on the constituents of chondrites, such as chondrules, matrices, mineral and "lithic" fragments and inclusions showed that the chondrules are secondary products which were formed from the aggregate of the pre-existing minerals through incomplete or complete melting and that the matrix materials are extremely primitive which were condensed from the nebular gas. They have offered important informations for the estimation of chemical and physical conditions and processes which occurred in the early solar nebula. Mineralogical studies on achondrites succeeded to reconstruct the layered structure of their parental body (or bodies) with the radius of several hundred km. These studies have given important points of view for Japanese earth scientists, especially for geologists, to look at the earth as one of the planets of the solar system and to consider the origin and evolution of the earth.