Sulfide minerals such as horomanite, pentlandite-like mineral, digenite, covellite-like minerals are found in plagioclase lerzorite from Horoman peridotite massif, hokkaido. Occurence, mineral assemblage, chemical composition of these minerals are report.

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Mantle peridotites overlying the metamorphic sole from the Oman ophiolite were examined. They are predominated by harzburgite and lherzolite, and their degree of serpentinization notably decreases upward from the base. Olivine is Fo90.7 to 92.5, and the Cr# of spinel varies from 0.2 to 0.6. Recrystallized (neoblastic) pyroxenes are characteristically low in Al and Cr. Horblende is commonly found in the peridotites. These characteristics indicate low-temperature metamorphism assisted by aqueous fluids suppled from the metamorphic sole.

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In this paper, we examined the performance of quantitative mineralogical analysis using Rietveld pattern fitting method. Synchrotron X-ray powder diffraction data of an artificial mixture of two to four mineral phases composed of five natural heavy minerals which include garnet, epidote, titanite, hornblende and clinopyroxene were used in the analyses. Quantitative information was extracted from refined individual scale factors and unit-cell volumes (derived from refined unit-cell parameters), obtained with a Rietveld program, RIETAN-FP. The method developed was applied to the provenance study of ancient ceramics.

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The Victoria gold deposit was classified as a low-sulfidation epithermal deposit. However, high-sulfidation state minerals are identified at deeper levels in the Victoria gold deposit in this study (e.g. luzonite, enargite and colusite). luzonite group minerals and chalcopyrite often overprinted the pre-existing vein materials. Luzonite group minerals of this type often replace tetrahedrite group minerals, and often show a small scale flaky intergrowth structure and banding structure of submicron order, with chalcopyrite. It is considered that these structures are formed by decomposition of intermediate-products which replaced tetrahedrite group minerals. The sulfidation-state of a mineralizing fluid during the last stage corresponds to high-sulfidation.

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Obira deposit zone belong Sengendera deposit mines mainly Sn, and is characterized by occurrence of borosilicate. Sengendera skarn deposit is rich in Fe and is known the source of borate : vonsenite occurred pneumatolytic deposit of high temperature. Vonsenite occurs with black aggregate acicular and columnar and with together pyrrhotite and andradite. Hulsite resemble vonsenite and are associated magnetite and greenish black amphibole have abnormal interference color occur in a part. Hulsite contains Sn component average of 9.83wt% and 0.16mol% and is not reported in Japan. (Ferri-)Ferro-hornblende contains Sn component maximum of 1.33wt%, and there are few report examples of Sn-bearing amphibole.

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Mineral paragenesis of massive chromium deposit from Higashi-Akaishi peridotite mass has studied. The rim of ore body has altered, and much chromian chlorite, Cr-diopside, Cr-amphibole, phlogopite, and a small amount of uvarovite. Chlorite and diopside are identified two type by amount of Cr. Chromite has 0.83 Cr#(=Cr/(Cr+Al)) on the average. Some chromite has referable to magnesiochromite, because these has Mg#(=Mg/(Mg+Fe)) over 0.5. Sulfides are some kind of Fe-Ni sulfides and Cu sulfides.

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Ternary feldspars in Garnet-bearing felsic gneiss from the Mt. Riiser Larsen in Napier Complex, East Antarctica have the characteristic exsolution lamellae. Although the metamorphic temperature was estimated from the re-integrated chemical composition of ternary feldspar, the formation mechanism of the microtextures in feldspar had not been studied well. In this study, we classified the exsolution textures in term of character of exsolution lamellae occurrence. Furthermore, the orientations of interfaces between each exsolution lamellae were determined using EBSD and the microtextures in feldspar were observed using TEM. We revealed a formation process of the typical textures in ternary feldspars and gave some constraint to the cooling process of the felsic gneiss.

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Mid Miocene volcanic rock (Utsuno volcanic rock) that is occurred in backbone range of NE Japan was observed to understand that forming process by OM, SEM-EDX, TEM. The phenocrysts of augite, orthopyroxene and plagioclase were crystallized at 1100 degrees C, >10kbar in the magma. After that, the magma mixed another Fe-rich magma and augite and orthopyroxene were altered to pigeonite at 1100 degrees C, 5-<10 kbar. In addition, plagioclase was resolved and made reveres zoning rim. Finally, rapidly erupted to the near the surface.

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