この論文では,釜石鉱山の代表的な鉱床である日峰,新山および天狗森鉱床を記載し,互い.に比較する,これらの鉱床は,蟹岳複合岩体の西翼に位置し,ほぼ南北に配列している.これらの鉱床におけるスカルンの累帯配列は,次の通りである.
日峰鉱床:閃緑岩またはホルンフェルス/斜長石-単斜輝石スカルン/ザクロ石-単斜輝石スカルン/単斜輝石スカルン/石灰石
新山8D鉱体:閃緑岩/斜長石-単斜輝石スカルン/緑レン石-単斜輝石スカルン/ザクロ石-単斜輝石スカルン/単斜輝石スカルン/石灰石
新山4D-7D鉱体:閃緑ひん岩/斜長石-角閃石スカルン/緑レン石-角閃石スカルン/緑レン石-単斜輝石スカルン/ザクロ石-単斜輝石スカルン/ザクロ石スカルン/単斜輝石スカルン/石灰石
天狗森鉱床:砂岩/緑レン石-角閃石スカルン/緑レン石-単斜輝石スカルン/ザクロ石-単斜輝石スカルン(I)/単斜輝石スカルン/ザクロ石-単斜輝石スカルン(II)/石灰石
CaO-MgO-AL₂O₃-SiO₂-H₂O-CO₂系およびCaO-Fe-AL₂O₃-SiO₂-H₂O-CO₂-O₂系の相平衡図より,上記のスカルン累帯配列の相違が,生成温度の違いに基づくことが説明される.生成温度は,天狗森鉱床,新山4D-7D鉱体,新山8D鉱体そして日峰鉱床の順に,すなわち,南から北に向って増加していると考えられる.このような結論から,等方性ザクロ石と異方性ザクロ石の転移温度はおよそ400～440℃であることが推定される.このような温度勾配は,蟹岳複合岩体に属する閃緑岩および閃緑竕岩によりもたらされたと考えられる.

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Neogene stress field in Hokkaido has been analyzed, based on the strikes of ore veins. The ore veins formed during the period from late Middle Miocene to Recent are taken into account. Those of E-W and ENE-WSW directions are predominant in both northeast and southwest Hokkaido.
The major veins of thirteen representative mines are formed in the conjugate shear fractures, that is, E-W or ENE-WSW dextral and NW-SE sinistral. The estimated stress field is NW-SE or WNW-ESE compressional and parallel to the direction of the subducting Pacific Plate, even at ore-forming period. The predominance of E-W and ENE-WSW dextral shears might be related to the oblique subduction of the Pacific Plate.

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HCl(1M)とHF(0.1～20M)を含む溶液を用いて,ズニ石, AL₁3Si ₅O ₂₀F ₂(OH, F) ₁₆Clの安定関係を1kb, 300～600℃で決定した.上記の組成となるように酸化物を混合し,これに天然産のズニ石を種として加え,400℃の溶液で処理した産物を出発物質とした.ズニ石の安定領域は比較的狭く, HF濃度が2M以下の溶液中でのみ安定である.1MのHF溶液中で,ズニ石は450℃まで安定であり,これ以上の温度ではトパーズに変わる.HF濃度がこれ以下の場合,ズニ石の安定な温度の上限はほとんど変化しない.HF濃度が3Mの場合,470℃以上ではトパーズが安定で,それ以下の温度ではトパーズにAlF ₃相が加わる.この組合せの安定領域は,HF濃度の上昇とともに高温側に広がる.HFが10Mのような高濃度の領域では,石英+AIF ₃が安定となる.
ズニ石の産出がトパーズに較べて稀なのは,温度の他に,化学的条件が限られていることによる.FとClはこの鉱物にとって不可欠である,しかし,Fの活動度が上昇すると不安定になる.珪長質火山岩の変質帯にズニ石が塊状をなして産出するのは,変質時における極端な溶液の挙動と物理化学的条件を物語っている.

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Propylite is widely developed in the Tertiary volcanic districts of Japan. In particular, it occurs typically in Toi-Seigoshi mining area, Idzu Province (Peninsula) Japan, where many epithermal gold-silver veins are found. KATO (1931) asserted that propylitization of the andesite in this area consists essentially in the formation of albite or potash albite at the expense of original lime-soda feldspars. According to him, the gold-silver mineralization began with the propylitization of andesites, succeeded by formation of gold-silver veins.
The writer has studied the propylites in this area and also in the Kushikino mining area of the southern Kyushu district.
The gold-silver veins of the Seigoshi mine occur both in propylite complex (Yugashima Miocene Formation) and in intruding dolerite or basic andesite dike (Fig. 1). The dolerite or basic andesite of the dike was subjected to weak or no propylitization. The propylitization of propylite complex and dike rocks is not controlled by the vein fissures. The writer concludes that the propylitization has no direct relation with the vein formation. It would be formed by autohydration or deuteric alteration.
The writer recognizes that the feldspar of propylite in this area is intermediate or basic plagioclase. It was replaced by orthoclase within 20-25m from the gold-silver veins. It has been confirmed by the microscopic observation, staining method of potassium in the uncovered thin section, electron microprobe and X-ray diffraction (Fig. 2, 3).
It is certain, I think, that albite or potash albite recognized by KATO in this area corresponds to orthoclase stated above. The formation of orthoclase would be closely related to vein deposition.
The plagioclase in dolerite or basic andesite is also replaced by orthoclase along the veins. The formation of orthoclase, i.e. potassium metasomatism is stronger in the propylite than in the dolerite-basic andesite dike. It would be due to the fact that before the intrusion of the dike potassium metasomatism began along the same fissure as the dike and continued during the dike formation and the vein deposition.
The formation of orthoclase is also recognized in the propylite adjoining the gold-silver veins of the Kushikino mining area, southern Kyushu (Fig. 4).
In the Kushikino mine, the potash feldspar zone grades into the sericite-montmorillonite (or mixed layers of both minerals) zone at the upper parts of the vein (Fig. 5).

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