中新世の温川黒鉱型塊状硫化物鉱床のカリウム・鉄質緑色粘土の産状と化学組成を光学顕微鏡法,電子線マイクロプローブ分析およびX線回折法により調べ,中新世の南白老黒鉱型塊状重晶石鉱床のそれらと比較した.
温川の緑色粘土は,黒鉱の胚胎層準近くの上盤火山砕屑岩中に,ペレットや空隙の充填物,さちに,マトリックスの交代物また充填物として産する.空隙を充填するセラドナイトを除くこれらの粘土は,その産状タイプに依存しK₂Oと相関しAL₂O₃と逆相関する広範囲のFe₂O₃組成変化を示す.この変化を海緑石―スメクタイト系鉱物による組成変化とすることができる.海緑石―スメクタイトからなる南白老緑色粘土のペレットとマトリックス充填物のタイプも,温川粘土と比べ,同様ではあるが,アルミニウム質スメクタイトへと連なるより幅広い組成変化を示す.加えて,南白老粘土のKとMgの含有量は温川粘土と比べより低い.
これら緑色粘土の産状と化学組成の様相は,温川粘土が熱水起源であったこと,また,砕屑性Al質粘土に由来する南白老粘土のスメクタイトから海緑石への転換が一様ではなっかたこと,によるものであろう.これらカリウム・鉄質緑色粘土は,古海底熱水鉱床である黒鉱型鉱床と生成上の関係を有するものであろう.

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約60個の濃飛流紋岩の試料,および流紋岩の基盤をなす堆積岩の試料数個について,酸素同位体分析および主要・微量元素分析を行った.幾つかの流紋岩については水素同位体分析も行った.流紋岩はすべて脱ガラス作用をうけており,また絹雲母・緑泥石・緑簾石・方解石・スメクタイト・スメクタイト/バーミキュライト混合層鉱物などの変質鉱物を生じている.流紋岩の全岩酸素同位体組成は-5.2～+9.2‰(SMOW)の広い変化を示し,また全岩水素同位体組成は-112～-102‰(SMOW)であった.このような変質をもたらした熱水は,天水起源の循環水であったと考えられる.熱水循環は濃飛流紋岩を完全に浸しながら進行し,基盤の堆積岩中にも及んでいた.流紋岩の少なくとも一部は,300℃以上の温度で,高い水/岩石比の下で,変質作用を蒙っている.¹⁸Oを濃集した岩石が殆どないという事実は,充分な酸素シフトを起こした熱水は殆ど形成されなかったか,形成されても岩石との間の同位体交換反応は不活発であったことを意味しており,殆ど酸素シフトを起こしていない新鮮な水が直接深部にまで達していたことを示している.主要元素を検討した結果,熱水変質により殆どの流紋岩でNa含有量が減少したこと,K含有量にかなりの増減を生じたことが判った.TAKENO(1989)のシミュレーションによれば,このようなNaに不足した岩石は流入帯で形成されたものではないと考えられる.一部のKに富む岩石は流出帯で形成されたものかも知れない.

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Carbonate and phosphate minerals, and boemite in the seven Paleogene coal seams of the Ashibetsu colliery in the Ishikari coalfield, Hokkaido, were investigated by X-ray diffraction for low temperature ash, shale, and tuff. A scanning electron microscope (SEM) equipped with an electron probe X-ray microanalyzer (XMA) was used to observe the morphology of carbonate minerals and apatite.
Calcite is the most abundant among the minerals studied, and is contained in 83% of the seventy five coal samples containing less than 40% ash. Ankerite is also abundant, and was found in 71% of the coal samples. Both calcite and ankerite appear as cleat and fracture fillings in the Ashibetsu coals. Aragonite is rare, and is thought to appear as a part of cleat and fracture fillings. Carbonate minerals are rare in shale. The Ca, Mg, and Fe content in the low ash and pyrite free coals, rich in calcite and/or ankerite, is estimated to be nearly the same as in plants or peats. This indicates that these minerals may have been formed in cleats and fractures by interaction of Ca, Mg, and Fe, and CO₂, released from organic material during the second stage of coalification.
Siderite is found in 20% of the coal samples, and is rare in shale. Siderite occurs as aggregates composed of fine grains or nodules of different sizes from less than 1 μm to 10 μm. Dolomite (ferroan dolomite) appears in only 4% of the coal samples, and also occurs as aggregates of nodules of irregular shape, up to 100 μm. Both siderite and dolomite are syngenetic minerals in the Ashibetsu coals.
Apatite are found in 63% of the coal samples containing less than 40% ash. All of the apatites found in the Ashibetsu coals are thought to be fluorapatite. Detrital apatite appears in the mineral band or mineral rich part of the high ash coal seams, and epigenetic apatite appaers as fracture fillings in the low ash coal seams. Apatite is rare in shale. Goyazite was detected in the samples that were relatively rich in apatite. Goyazite coexists with both detrital and epigenetic apatite. As P correlates well with Sr, these two phosphate minerals are thought to be closely related in origin.
Boemite is detected in 32% of the coal samples, most of low ash content. Organic Al may be the source of boemite.

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Metallic mineralization in the Suehiro vein and its neighbouring veins of the Otome deposit was described. The metallic minerals of the Suehiro vein and its neighbouring veins are ferberite, pyrrhotite, less pyrite, chalcopyrite, sphalerite, molybdenite 2H, goethite, arsenopyrite, cubanite, Ag, Sb-bearing cosalite, bismuthinite, native bismuth, ingodite, Bi-bearing boulangerite, izoklakeite etc.
The mineralization sequence at Otome can be divided into three stages, based on microscopic observation, EPM analyses and fluid inclusion data: Stage I (W mineralization), Stage II (sulphides and sulphosalts), and Stage III (hematite and goethite). Further, the stage II is subdivided into three substages. The fluid inclusion homogenization temperatures ranged from 350°to 250°C for stage I, from 330° to 150°C for stage II and lower than 150°C for stage III.
Temperatures and sulfur activities of stage II mineralization at Otome are estimated as 330° to 150°C, and -11 to -20 in log aS₂ (atm.), based on the FeS contents of sphalerite, mineral assemblages and fluid inclusion data.

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