Various Ca-zeolites such as wairakite, yugawaralite, laumontite and epistilbite have been found in veinlets cutting the weakly metamorphosed basaltic rocks of Miocene age in Kuroishi near Hirosaki. The mineral assemblages of the host rocks indicate that they were subjected to the prehnite-pumpellyite facies metamorphism. Microprobe analyses were obtained for these Ca-zeolites.
Each of these Ca-zeolites usually occurs in different veinlets, but sometimes wairakite is replaced by one of the other Ca-zeolites. Probably they were formed at different stages of the metamorphism and hence under different P-T conditions in the order of wairakite, yugawaralite, laumontite and epistilbite.
The feebly metamorphosed basaltic rocks should have experienced a geothermal gradient as high as in active geothermal fields. Such steep geothermal gradient was probably not rare in the Miocenc metabasite areas in the environs of Hirncnki.

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The Cretaceous Hanawa pluton and neighboring metamorphic rocks are described from the geological and petrological viewpoints. The Hanawa pluton consists of, in order of formation, fine-grained quartz diorite and tonalite, foliated tonalite and granodiorite, and main granodioritic rocks. The granodioritic rocks are subdivided into porphyritic type, large sphene-bearing type, mylonitic type, and fine-grained equigranular type.
In general the younger the rocks are, the richer in potash feldspar and quartz and the poorer in mafic minerals. Chemical compositions of 13 granodioritic rocks vary within a rather narrow range (SiO₂ 67-73%), and are similar to those of average Japanese granitic rocks. Mg/(Mg+Fe) ratio of biotite and An content of plagioclase decrease toward the southwestern side of the granodioritic pluton.
High-grade metamorphic rocks including orthopyroxene-bearing granulite are distributed far away from the Hanawa pluton, whereas medium-grade metamorphic rocks near or in the pluton. This finding suggests that the intrusion of the Hanawa pluton does not play an important role in the formation of the high-grade metamorphic rocks.

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So-called late Cretaceous-Paleogene quartz monzodiorite stock (13 km²) and small dolerite dike in the Arashima-dake-Nakatatsu Pb-Zn mine area were dated as 18.3-20.9 Ma and 24.8 Ma, respectively. Thus, Miocene plutonic cycle should be added to the plutonic activity of eastern Fukui Prefecture, where Jurassic and late Cretaceous-Paleogene ones were recognized before. The Kadohara quartz monzodiorite is high-level portion of volcano-plutonic complex, which is a part of intense andesitic activity of the Green Tuff orogeny.

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Dolomite was found in Sanbagawa pelitic and basic schists from the Bessi and Asemigawa-Sarutagawa areas in central Shikoku. The dolomite occurs in two modes: (1) as independent and coarse crystals of 0.2-1.0mm in size; and (2) as rounded and small (0.01-0.1mm in size) crystals dispersed in large calcite crystals. The independent crystals of dolomite are always replaced by secondary calcite and included in garnet porphyroblasts, and hence they are regarded as a product of the Sanbagawa prograde metamorphism. The small dolomite crystals of the second type are probably an exsolution product formed by re-equilibration of Mg-rich primary calcite during retrograde metamorphism.
The coexisting independent crystals of dolomite and calcite show equilibrium temperatures of about 540-570°C and 580-620°C in the albite-biotite and oligoclase-biotite zones, respectively.
Dolomite+quartz assemblage occurs mostly in the oligoclase-biotite zone of the highest grade, and was not observed in the chlorite and garnet zones of lower grade. On the other hand, tremolite+diopside+calcite+quartz and talc+ calcite+quartz assemblages occur in crystalline limestones and basic schists in the garnet and albite-biotite zones. These facts suggest that (1) X_co2 of metamorphic fluid was limited to low value in the low grade zone of the Sanbagawa terrain, and (2) X_co2, value of the metamorphic fluid in the oligoclase-biotite zone tends to be higher than that of the lower grade zones.

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