The segmented structure of Cretaceous to early Paleogene granitic batholiths of the Japanese Islands are discussed on the basis of statistics of major element chemistry. It is concluded that they comprise four main segments, the Northern Kyushu, Ryoke, Tohoku and Do-nan, and five across-arc sub-segments, the San-in, San-yo and the Ryoke in the Ryoke main segment and the Kitakami and Abukuma in the Tohoku main segment. The granitic batholiths of Cretaceous Sikhote Alin, Cretaceous Southern Korea and lower to upper Cretaceous Southeastern China show no intimate relations among them. The Sikhote Alin rather resembles to the Do-nan and Uetsu granitic provinces of the Japanese Islands and the Southern Korea to San-in and Shirakawa. The Northern Kyushu batholith is unique and independent of surrounding granitic batholiths.

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From the mode of occurrence and the chemical and mineralogical composition of granitic rocks, three granite provinces, designated, East, Central, and West zones are recognized in northern Kyushu. These zones are separated by the Kokura-Tagawa and Hakata-Futsukaichi tectonic lines, respectively.
Although most granitic rocks in the East zone belong to the ilmenite-series, the granitic rocks in the Central and West zones belong mostly to the magnetite-series and partly to the ilmenite-series.
Recognition of the importance of chlorine complexing in enhancing the solubility of metal sulfides in aqueous solution had led to the view that the chlorine content of intrusive rocks could govern the ability of a magma to separate a metal-rich hydrothermal phase. Relatively high chlorine contents were obtained for apatites, biotites, and amphiboles from the Central zone granitic rocks, low chlorine contents were obtained for the same minerals from the West zone granitic rocks, and the minerals from the East zone granitic rocks are essentially chlorine-free.
From the structure and texture of the granitic rocks and from the chemistry of the granitic rocks, it is suggested that the East and Central zone granitic rocks are high level intrusions compared to the West zone granitic rocks.
If hydrothermal transport of base metals in chloride complexes is accepted, it is suggested that most of hydrothermal base metal deposits in northern Kyushu were associated with the Central zone granitic magmas. The presence of contact metasomatic copper deposits in the Yoshiwara mining district supports the conclusion just mentioned.

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Small stock (13 km²) named as Hobenzan pluton of middle Cretaceous age is located geologically in W-province of Sanyo Belt but is associated with many vein-type copper deposits, which are characterized by the presence of tourmaline and polymetallic ore mineral assemblages including As, Co, Bi and W. The stock is composed of biotite-hornblende granodiorite and granite (12 km² in exposed area) and some biotite aplitic granite (1km²) and trace of quartz monzodiorite. The granodiorite and granite have magnetic susceptibility of magnetite-series values in general but are characterized by low range as 100-565×10^-6 emu/g and also by local ilmenite-series values, on which local reduction due to admixing of sedimentary wall rocks can be considered. The Hobenzan granitoids are after all an independent, intermediate-series between typical magnetite-series and ilmenite-series granitoids. The aplitic granite may be in situ differentiates of the original granodioritic magmas.
Chemically, these granitoids are also intermediate, because the major components are similar to those of the average composition of Japanese granitoids, except for K₂O which is distinctly higher than the average composition. Among trace elements, Cl and S contents show characteristics of magnetite series but Rb, Sr, Pb and Li contents are more akin to those of average ilmenite-series granitoids in Japan. Yet, no strong concentration of Rb, Pb, Li and Sn is observed in well differentiated facies of the pluton. Sulfur isotope ratios of rock and ore sulfur mostly fall between +2.2 and +0.6%s δ⁸⁴S(CDT), indicating magmatic source for the ore sulfur.
The Hobenzan granitoids may have originated in lower continental crust materials that have a moderate Fe₂O₃/FeO ratio and high contents of K₂O, Cl, S, Cu and B. Such a crust may be expected originally in the Asiatic continent. Chlorine may have played most important role to concentrate the ore metals in and around the Hobenzan pluton.

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Isotopic composition is determined for ore sulfur from 16 skarn-type deposits associated with Cretaceous felsic igneous activities in the westernmost part of the Inner Zone of Southwest Japan. Together with the data available in the literature, a trend of gradual increase in ³⁴S content to the north is recognized in the area, that is, isotopically light ore sulfur as-7 to -10‰ (CDT) in the southern deposits close to the Ryoke belt and heavier ore sulfur as 0 to +3‰ in the northwestern deposits. This trend is in harmony with, and consequently is supposed to be caused by, the lateral variation of the nature of the granitic rocks intruded in the studied area. The trend seems to be continuous to the Gyeongsang basin, the southeastern corner of the Korean peninsula. Any significant difference, however, is not observed between isotopic compositions of ore sulfur from the deposits distributed at the both sides of the Kokura-Tagawa fault zone, where an abrupt change is reported in the nature of the granitic rocks from ilmenite series to magnetite series.

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Granitic rocks of the Iwakuni-Yanai district in the southwestern Japanese mainland (Honshu) have been classified into three distinct series: Sanyo, Ryoke (younger and older) and Sannin types. The present study involeves the former two.
Examinations of the mode of occurrences and petrographical studies including the variation of chemical compositions of Sanyo and Ryoke granites revealed that they are in reality cogenetic. They can be called as the "Ryoke-Sanyo" series. This study points out also the existence of migmatitic concordant granites occurring in small dimensions in the Ryoke metamorphic rocks of high grade part.
No compositional differences were observed between slightly metamorphosed sediments of the Kuga formation (Jurassic) and Ryoke metamaophic rocks constituting the country rocks of these granites. The latter can be considered as metamorphic (green schist facies to high grade part of the amphibolite facies) equivalent of the former.
Granite masses of the "Sanyo type" granites are intruded discordantly into their country rocks (the Kuga formation and low grade part of the Ryoke metamorphics). They are homogeneous in each masses with great dimensions of batholithic order. They manifest on the variation diagram, compositions of advanced differenciation characterized by extremely poor MgO content and Q: Or: Ab ratio close to that of the "ternary minimum (or eutectic depending on vapour pressure) composition of the granite system".
The "Younger Ryoke" granites are intruded discordantly into the country rocks. Dimensions of each individual masses of this types are much smaller than those of the "Sanyo" granites. The varaiation range of their chemical compositions are wider than that of the "Sanyo" granites, but the trend is same. It is considered from the mode of occurrences and petrographical characters that the granites of the "Younger Ryoke" granites represent rock facies formed in levels deeper than olaces where the "Sanvo" granites were consolidated.
Besides these discordant granites, there are gneissose granites of small dimensions in several places (typical example can be seen at Oshima) in high grade part of the Ryoke metamorphics. They are concordant to the country rock. Their chemical composition is different from above two types and show the same trend in MgO-AL₂O₃, Total Fe-AL₂O₃, TiO₂-AL₂O₃ and K₂O-MgO relations as those of the Kuga formation and Ryoke metamorphic. These granites (migmatites) are considered to be formed in situ in the Ryoke metamorphics through partial fusion of metamorphic rocks whose compositions were modified by the metasomatic replacement caused by percolation of fluids of deep origin.
From these obserations, it is concluded that granites of the Sanyo and Ryoke type of the district belong to the same series named as the "Ryoke-Sanyo" granite series.

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Chlorine and fluorine contents of the Neogene granitic rocks in Kyushu were analyzed by an X-ray fluorecence analyzer and a specific ion electrode. Based on the petrography, Kyushu is divided into the. Inner zone, the Outer zone I and the Outer zone II from NW to SE. With some exceptions, chlorine and fluorine decrease as SiO₂ increases in each granitic mass. From the halogen contents in large granitic masses in the three zones, it is suggested that the chlorine content decreases and the F/Cl ratio increases toward the Pacific Ocean side. These trends correspond with those of other geochemical data which have been explained by the differences in modes of generation and granitic magma emplacement. On the other hand, the hypabyssal rocks in this region show a different pattern of halogen content from the plutonic rocks, indicating that the mode of emplacement affects the behaviour of halogen elements.
Granitic rocks of the Inner zone associated with base metal mineralization are rich in chlorine. Those of the Outer zone I are characterized by rather high fluorine content. Whereas, some hypabyssal rocks closely related to tin mineralization in the Outer zone I contain high chlorine concentrations or minerals with high chlorine contents. Hence, it is thought that chlorine plays an important role in transportation of tin, but that fluorine is enriched during differentiation process or by later greinsenization. There are some small tungsten-tin ore deposits in the Outer zone II. It is thought that there is no intense mineralization in the Outer zone II, because of the low chlorine content of the granitic rocks..

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