Recent advances in various aspects of experimental petrology is reviewed. It is noticed that the research projects have been shifting from the studies on the rocks and minerals on or near the Earth's surface, to those in the crust and finally to those in the upper mantle, corresponding to the progress in the high pressure experimental technique. EPMA and Mossbauer spectrograph have been prooved indispensable as the identification method in these fields.
At first origin of granites is discussed by means of various studies on the system albite-orthoclase-quartz-H₂0, with or without anorthite or various mafic minerals. It is now generally agreed that majority of granites are formed from liquid phases, either the primary magmas or secondary liquids resulted from melting of pre-existing rocks.
Formation of basaltic magmas by partial melting of lherzolite in the upper mantle is discussed by means of the studies on the forsterite-diopside-silica system at atmospheric pressure or higher pressures. It is evident from these studies that pressure has close relation to the composition of the magmas thus formed, indicating increase in alkalis with increasing pressures.
Olivine (α-form) and spinel (γ-form) transition in the system Mg₂Si0₄ Fe₂SiO₄ has been studied at several laboratories at pressures up to 250kb. During these studies an intermediate phase of “modified spinel” (β-form) has been found in the compositions close to pure Mg₂SiO₄, making the phase diagram of Mg₂SiO₄-Fe₂SiO₄ very complicated. Decomposition of clinopyroxenes of the system MgSiO₃-FeSiO₃ into spinel and stishovite at very high pressures was also found. Behaviors of several minerals of the upper mantle, such as amphiboles and garnets, have been studied at moderate pressures. It is noted that ugrandite-and pyaralspite-series of garnets form continuous solid solutions at higher pressures.
Genesis of andesite, one of the most fascinating subjects in modern petrology, is discussed with the results of experimental works, especially by the study of forsterite-diopside-silica-H₂0 system at various pressures. Kushiro presented a hypothesis of direct derivation of andesite from hydrous lherzolite by partial melting at depths of about 80 km. Relation between andesite magma generation and the plate tectonics is also discussed.
Shock-wave experiments can produce ultrahigh pressures and temperatures up to 10Mb and 10, 000°C, though the time being in the order of 10^-6 second, and provide a basis for experimental studies of shock metamorphism, which has been observed only in some terrestrial impact craters. Importance of this new category of metamorphism is discussed.
In spite of remarkable advances in the experimental studies under high pressures, the author still believes that atmospheric pressure studies have to be continued as the basis on which high pressure studies are constructed. They also provide many informations relevant to the interpretation of ystallization of magmas and metamorphic processes of crustal rocks on the Earth's surface.
Finally interdisciplinary and international nature of the experimental petrology is discussed.

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Natural rhyolitic tuff and green tuff (Miocene age) were subjected to alter in sodium hydroxide solution under 200°C and 20kg/cm². When these were treated at 200°C for 50 hours, analcime (NaAISi₂O₆•H₂O) was formed as an alteration product, whose X-ray reflections were gradually intensified with the duration of treatment. From the diffraction intensities, it was found that the alteration products of green tuff contained about 3 times more analcime than in the case of rhyolitic tuff. A comparison of chemical compositions between the original green tuff and its alteration products showed that SiO₂ was much dissolved out in the process of analcimization. On the basis of the present result, it is considered that the analcime zone surrounding Kuroko deposits is formed by the reaction between highly saline alkaline solution and tuffaceous sediments of middle Miocene age. The solutions are considered to have been heated by submarine volcanism and/or exhalative activities, thus accelerated the alteration.

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