1. Six samples with different colors, textures, etc., were selected according to the depth in the soil derived from granodiorite at Ogoe, Fukushima Prefccture.
2. After the collected materials in wet state were treated with 6% H₂O₂ in order to disolve organic matters, they were dispersed in the NaOH solution with. pH 8.5. These dispersed materials were separated is eight fractions by sedimentation method and centrifugation, and then the iron-hydroxide were removed by using Truog's method.
3. The mineral compositions of the sand fractions with diameter over 0.02mm were quantitatively investigated under microscope. The materials of the fractions of <0.2μ and 0.5-1.0μ were studied by means of X-ray powder photograph, chemical analysis and differential thermal analysis.
4. From these experiments it was confermed that nontronitic montmorillonite, halloysite, kaolinite, degraded illite and their interstratified mineral occur in the soil profile
5. It seems that the nontronitic montmorillonite was formed at the early stage of the weathering of granodiorite rich in bases.
6. It has been followed by the formaticn of halloysite and kaolinite.
7. The change of soil condition seems to be the cause of the formation of interstratified mineral.
8. In finer fraction halloysite is contained far more than kaolinite, while kaolinite is much more in coarser fraction.
9. The degraded illite is a weathering product cf biotite.

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The chromite bodies at the Hiroosa mine consist of massive chromite, of grains disseminated in serpentinite.
In thin section the dusty magnetite and yellowish brown chlorite are abundant in darker variety of serpentinite, but in greenish serpentinite those are scarcity.
Chromite in serpentinite rarely has black margins and is crossed by black opaque material, presumably ferrian chromite or chromian magnetite.
Chromite samples analyzed by the present writer gave a content of CT₂O₃ ranging from 47 to 52% and Cr/Fe ratio of 1.7 to 2.1. It appears likely that there may be systematic variation from spinel molecule to magnetite molecule in composition of the chromite. It seems that FO₂O₃ is concentrated in the residual solutions.

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上述の熔融硫黄中に於ける斑銅鉱の熱的変化を要約すれば
1)120°C以上で斑銅鉱は周囲の硫黄と反応してその周縁部に銅藍帯を形成する。もしこの場合斑銅鉱中亀裂が存在する場合にはそれに沿つて細脈状乃至網状を呈す銅藍の生成をみる。
2) 140°～450°C,1hr.加熱で斑銅鉱中に格子状,レンズ状,滴状,蠕虫状,準細胞状及び懸滴状の黄銅鉱が析出する。そのうち格子状黄銅鉱は140°C～320°C,1hr.加熱で銅藍反応縁の近くに限つて現われ,滴状のそれは前者より高温の240°C～420°C, 1hr.加熱で主として斑銅鉱の内部に現出,一方レンズ状黄銅鉱は屡々2箇一対として析出し,これは高温または長時間加熱によつて滴状黄銅鉱に変化する。これら黄銅鉱の析出は銅藍の生成にともなつて形成された斑銅鉱一黄銅鉱固溶体の離溶現象である可能性が強い。
3)300°C, 1hr.以上の加熱で斑銅鉱様鉱物が主として銅藍反応縁と斑銅鉱との境界部に現出する。この鉱物の性質は略々斑銅鉱に類似するが,異方性が極めて強い。
4) 360°C以上の温度で斑銅鉱及び初生の塊状黄銅鉱中に黄鉄鉱が現出する。
等で,これらの現象と温度との関係を表示すれば,
の様である。以上の実験結果から
a) 天然産鉱石鉱物のあるものは上記の様な熱分解によつて生成される可能性がある。
b) 熱分解によつて生じた2次的固溶体の離溶は実験室丈ではなく地質学的現象にも起る可能性が濃い。
等のことが老えられ,4に鉱床が火成岩の迸入や後期の鉱化作用を蒙むる様な場合に上記の様な現象を期待出来る。

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The Kaaenosawa mine is located about 5km northwest of Horobetsu station, Iburi province, Hokkido.
The hollocrystalline rock, intruded into the Neogene formations,
is found in the neighbourhood of this mine. Especially, the relationship between this plutonic rock and metallic ore deposit, which has been discussed, is clear at this mine.
The geological complex, developed in the adjacent area of this mine, belong to the Neogene Tertiary, various kindes of volcanic, and Quarternary sediments. The Neogene Tertiary consists of the lower green tuff, quartz-diorite intrusived into the former rock (Fg. 3 showing its intruded relation), conglomerate and, upper green tuff in ascending order. The conglomerate is composed chiefy of chert and slate derived from the so-called Palaeozoic, and subordinately of diorite and green tuff derived from the Tertiary member. Its traced distance is very short, the thickness being about 60cm. Covering the Tertiary formations descrived above, the Quarternary sediments and volcanic, are widely developed through the elevated plateau of this district. They are mainly composed of the Noboribetsu mud lava and pumice bed in ascending order.
The ore deposits are embraced in the lowei green tuff, diorite and upper green tuff. Especially, the deposits which are now under mining are a vein-like type in the fault zone striking in N 80°E and in the brecciated none of diorite striking N 10°E. On the other hand, the network type deposits, which had produced. the higher trade ore of Au, Ag in the earlier development of these mine, are embraced in the clayed zone of Lower green tuff. Furthermore, the deposits showing the same mineral assemblage as in diorite, also exsist in the upper green tuff, covering the dicrite and the lower green tuff.
It is clear, accordingly, that the mineralization began after the deposition of the upper green tuff, and then the ore depcsiton here was. ultimately unrelated to the intrusion of quartz diorite. As covered by the Quarternary rocks, the accurate age of mineralization is unclear, but it is doubtlessly younger than the later Kunnui stage.

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