Magmatic evolution of Akita-yakeyama volcano, northeastern Japan, has been investigated based on bulk chemistry (major and trace), Sr isotopic features and mineral chemistry in combination with stratigraphical study.
The main body of the volcano was built by eruptions of a large amount of hypersthene-augite andesite magma and a minor amount of olivine bearing hypersthene-augite andesite magma as lava flows and pyroclastic falls, and an edifice of stratovolcano was built. No evidence of magma mixing or crustal assimilation can be recognized in the olivine free andesite, but olivine-pyroxene disequilibrium in the olivine bearing andesite indicates magma mixing. After a repose period, a series of eruptions began from the central vent and erupted hypersthene-augite andesite magma as fine ash fall and hypersthene-augite-olivine andesite magma as lithic-rich pyroclastic falls. As stated above the olivine-free andesite has no evidence of magma mixing, but the olivine bearing andesite has the mineralogical and chemical evidence of magma mixing, such as disequiliblium phenocryst assemblage, reverse zoning of pyroxene and dusty plagioclase. Flank eruptions followed and erupted quartz bearing olivine-hypersthene-augite andesite magma, quartz bearing augite-hypersthene andesite magma and augite-hypersthene dacite magma as lithic-rich pyroclastic falls, lava flows and pumice fall. Among them quartz bearing andesites have high ⁸⁷Sr/⁸⁶Sr ratios, suggesting the involvement of crustal assimilation. At the end of these eruptions, augitehypersthene dacitic lava dome and olivine bearing augite-hypersthene dacitic lava dome intruded into central crater. Dacite magma of the lava domes has no or little evidence of magma mixing or crustal assimilation. Chemical variation of trace elements (Zr, Rb, Y) from the hypersthene-augite andesite of the main body to the augite-hypersthene dacite of the domes cannot be accounted for by fractional crystallization, and difference of degree of partial melting of the source material is required.

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The Hiroshima Granite is Late Cretaceous large batholithic intrusion in Sanyo belt of southwestern Japan. It is composed of the following rock types; quartz diorite (QD), medium-grained hornblende biotite granite (MG), medium to coarse-grained biotite granite (CG) and fine-grained biotite granite (FG). QD occurs as xenolith in MG. The main parts are composed of upper CG and lower MG, and CG intrudes into MG. FG, the latest stage intrusion, is located at the upper most part beneath the roof. Thus, the Hiroshima Granite is vertically zoned. SiO₂ decreases from 76 to 71 wt% downward from the roof.
This vertical zonation may have been firstly formed by gravitational fractionation. Then, more differentiated liquid moved under the roof and resulted in the upper most FG.

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Laumontite and babingtonite associated with other secondary minerals have been found in a hydrothermally altered andesite of early Miocene age from the Fukaura district, Aomori Prefectture. This rock has a grey matrix characterized by the secondary mineral assemblage of chlorite+prehnite+epidote, but the minute primary plagioclase laths in its groundmass are chiefly repleced by laumontite. It also contains many white spots mainly filled with laumontite. The laumontite is close to the Ca-end member formula in composition. Babingtonite is found only in the dark green patches, irregularly distributed in the rock. The babingtonite has a restricted compositional field deviating from the idealized chemical composition with substitution of Mn²⁺ and Mg for Fe²⁺, and Al for Fe³⁺. The secondary minerals in the matrix except laumontite crystallized under the prehnite-pumpellyite facies conditions, followed by the hydrothermal formation of laumontite and then babingtonite. The babingtonite is considered to have crystall. ized under the conditions of the order of 100°C and 50 Pa P_totai.

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The Northern Marginal Zone of the Limpopo Belt is an Archean high-grade metamorphic terrane in Zimbabwe. It is mainly composed of charnockites and opx-free quartzofeldspathic gneisses (biotite-gneiss) with minor amounts of mafic and pelitic gneisses.
Temperature conditions of both the charnockite and the biotite-gneiss are estimated to be about 500-680°C from the compositions of coexisting magnetite and ilmenite. Oxygen barometry (fo₂) of the charnockite, estimated from ilmenite-magnetite and opx-magnetite-quartz assemblages, is higher and the range smaller than that of the biotite-gneiss. It suggests that the increase in the fo₂ level of quartzofeldspathic rocks above the QFM-buffer brought about charnockitization: The increasing fo₂ appears to be responsible for lowering a H₂O or elevating a CO₂, because of breakdown reaction of biotite and/or hornblende to form opx.

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