Data of the fluid inclusion studies•which have been carried out up to date in Japan, are briefly summarized, and the result is discussed from the standpoint of mineral exploration. Homogenization tempera• tures of fluid inclusions in vein-type deposits of Tertiary and Late Cretaceous age, range between 130° and 360°C, but the temperature range of main mineralization is from 200° to 300°C, and the base-metal mineralization is not prominent above 300°C. Systematic change of temperature and salinity is observed in fluid inclusions from the genetically related igneous rocks to veins far from the center of mineralization. Salinities of ore-forming fluids of Tertiary vein-type deposits are generally low, and the stable isotopic composition indicates a high possibility of participation of meteoric water to the mineralization, but there are some exceptions such as the Taishu and Avi deposits where the salinity of fluids reaches as high as 20 wt.%.
It is considered that stockwork orebodies of the Kuroko deposits which are found in rhyolite domes underneath the bedded orebodies have served as pathways for the ore-forming fluids of the bedded orebodies. There• fore, the fluid inclusion studies of the stockwork orebodies provide data on the fluids which were still in solid rocks of the sea floor
and not mixed w;i.th much of cold sea water. At the top of stockwork
orebodies, the'temperatures of fluid inclusions evidently drop but in the deeper places the temperatures are around 300°C and the gradient
of temperature is small. Fluid inclusion data of the Philippine porphyrycopperdeposits are interesting to mention compared with those of hydrothermal veins and genetically related igneous rocks. The de• posits are characterized by the presence of high-salinity and high• temperature polyphase inclusions. From the result of geologic and fluid inclusion study, it is inferred that an intense activity of highsalinity and high-temperature boiling fluids of magmatic origin has participated at the formation of vertically extended pipe-like ore Fourth Joint Meeting MMIJ-AIME 1980, Tokyo 1

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