韓国・蔚山鉱山のFe-W鉱床は, 慶尚盆地の白亜系分布域に狭小な "島" を成し超苦鉄質岩類を伴って発達し, かつ広義の仏国寺花崗岩系列に属する "加大里花崗岩プルトーン" に貫かれた時代不詳の石灰岩層に胚胎する石灰質スカルン鉱床であって, 複雑な多金属鉱化作用により特徴づけられる. そして, この鉱床はいくつかの Ni-Fe-Co 系砒化物・硫砒化物を伴っている. これら鉱物は紅砒ニッケル鉱, ランベルスベルジャイト, レーリンジャイト, 硫砒ニッケル鉱硫砒鉄鉱および輝コバルト鉱を包含する. しかし, レーリンジャイト・硫砒鉄鉱を除いたほかの鉱物の産出量はごく僅かである.
この論文は, 主として鉱石顕微鏡および電子プローブX線マイクロアナライザ(EPMA)によるこれら鉱石鉱物の研究結果を述べたもので, それらの産状および鉱物学的諸性質(主に光学的並びに化学的データ)が提示されている. そして, 著者らはこれら鉱物に含まれる Ni および Co め起源の問題に言及し, それは近くの超苦鉄質岩体に由来したことを示唆している.

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古生代火山岩累層中に胚胎される日立鉱山の多数の鉱床は,下位の酸性片岩と上位の塩基性片岩に挾まれる藤見鉱床群と厚い塩基性片岩中の不動滝鉱床群に区分される.層準の異なる両鉱床群の鉱石および鉱石鉱物の化学的性質を,主として藤見鉱床と不動滝鉱床において比較した.
黄鉄鉱のコバルト,ニッケル含有量は両鉱床間で有意の差が認められ,不動滝鉱床において多い.コバルト,ニッケル含有量の相違は,両鉱床をもたらした鉱液の両元素の含有量の違いに起因しているものと推論される.また両元素は一般に酸性火山岩に比較して, 塩基性火山岩に多く含まれるので,鉱液中の含有量は,鉱床下盤を構成する火山岩中の含有量を反映しているものと考えられる. 黄鉄鉱のセレン含有量,硫黄同位体比にも両鉱床間で明瞭な相違が認められる.鉛,バリウムは塩基性火山岩に比較して,酸性火山岩に多く含まれることが知られている.方鉛鉱の産出は両鉱床とも少量であるが,藤見鉱床の鉱石にわずかに多く含まれる. 重晶石は藤見鉱床の特に閃亜鉛鉱に富む鉱石に認められ,不動滝鉱床には産しない.
塩基性火山岩起源の片岩に伴う別子型鉱床の鉱石,鉱石鉱物の既存のデータは,調べた全ての元素について, 大旨不動滝鉱床に類似し,酸性火山岩に伴う黒鉱鉱床のそれらは藤見鉱床に類似している.これらの鉱床をもたらした鉱液は,鉱床に伴う火山岩の花学的性質を反映していると考えると都合が良いことになる.

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東アジアの各地には, 中生代～第三紀初期のおもに花こう岩質マグマの活動に密接に関連して生成された鉛・亜鉛鉱床と銅鉱床との広域的水平帯状分布がしられている. 最も顕著なのは日・韓両国, 次いで中国の東南部のものである. ソ連沿海州の鉛・亜鉛帯は日・韓両国の鉛・亜鉛帯の東方の延長にあたるものと思われる.
この帯状分布をおこした最大の地質的背景の1つは海洋プレートのもぐり込みによる大陸プレートの変動である. 上述の地質時代を通じ, 海洋プレートはほとんど絶え間なく当時のアジア大陸プレートの下にもぐり込んでいた. その結果, もぐり込みを受けた大陸プレートは押上げられ, 変動を受け, その一部にマグマが発生し, これに密接に関連して鉛・亜鉛鉱床と銅鉱床が生成された. その際, 鉛・亜鉛鉱床は大陸プレートの上部のより酸性の部分に生じたマグマに, 銅鉱床はその下部のより塩基性の部分に生じたマグマに関連して生成され, その結果両者の広域的水平帯状分布が生じた. 銅帯は当時の大陸プレートの縁辺部に位置し, 鉛・亜鉛帯はこれをふち取るようにその外側(大陸側)に位置する. この場合, 海洋プレートのもぐり込みの角度が小さい場合ほど, それぞれの帯の幅が広大となったものと思われる.
日・韓両国における同時代の鉛・亜鉛帯と銅帯とのずれからみて, 日本列島の南への相対的移動はこれらの帯の生成後, ほぼ5000万年前に開始されたものと思われる.

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the Kosaka mine situated in the northern part of Japan is a typical kuroko deposit mine.
Recently, oxidized ores are found in upper part of black ore, just below the Quaternary sediments in the Uchinotai-Nishi ore body. These ores are mainly composed of barite, quartz, cerussite, and goethite with small amounts of anglesite, galena, sphalerite, and malachite enriched in gold and silver.
With respect to the occurrence and mineral assemblage, four specific types can be distinguished. "A" type is sandy ore which is further subdivided into "A1" and "A2". "A1" is white colored and is composed solely of barite and quartz. "A2" includes a little goethite and cerussite in addition to the minerals of "A1" and has a brown color. The "B" type is characterized by barite, goethite, cerussite and quartz with minor amounts of anglesite and galena. It is a massive and porous ore, containing high amounts of gold and silver. The "C" type consists of barite and cerussite with anglesite, galena and sphalerite and has the highest content of gold and silver. Copper is concentrated as malachite in occasional parts of the "C" type ore. The "D" type is a sericite-rich clayey ore and contains barite, quartz and cerussite.
These ores evidently reveal zonal arrangments both vertically and laterally. In this paper it has been suggested that the ores were formed in situ by the supergene processes of black ore. By use of a Eh-pH diagram, conditions under which respective ore types were formed are inferred.

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Alabandites from Pretertiary bedded- and Tertiary vein-type manganese deposits in Japan have been examined for their sulfur isotopic composition. δ³⁴S (CDT) value ranges widely from -31 to +1.1‰ in 12 specimens taken from 10 bedded type deposits. While the mineral is no more than a minor constituent in most of the deposits, the isotopic features clearly indicate that these alabandites are of bacteriogenic sedimentary origin, thus raising an important constraint for the genesis of this group of deposits. A cluster of δ³⁴S around -30‰ implies an open-system, steady-state reduction (SCHWARCZ and BURNIE, 1973) from a source SO₄^2- with the isotopic level of ca. +20‰. The inferred source is likely to have been in the Triassic sea. Current conjectures upon the age of host sedimentary rocks of the deposits concerned are in favor of this view.
Alabandites from the Tertiary (Miocene) vein type deposits show only a minor variation in δ³⁴S, +4 to +5‰. The data are very similar to the average isotopic composition of sulfides of the Miocene, "Green Tuff", mineralization represented by the kuroko type deposits. The remarkable consistency in sulfur isotopic composition of the Green Tuff mineralization over an extensive area may require a huge, common reservoir of sulfur in some form, which still remains an enigma.

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The Kamioka Pb-Zn deposits are pyrometasomatic and hydrothermal replacements in Hida metamorphic rocks. The ore is divided into two types: The early "Mokuji" ore that is skarn-type ore with hedenbergite and epidote and the later "Shiroji" ore with quartz and calcite. Sericite occurs in the Shiroji ore or as an alteration product in the wall rock of the Shiroji. K-Ar ages of five sericite samples were determined to be 65.3, 65.1, 66.1, 67.5 and 63.8 Ma. The results show that the Shiroji mineralization took place near the end of Cretaceous. The Mokuji mineralization may be not much older than the Shiroji.
Recent finding of metamorphic skarn accompanied by pyrrhotite and sphalerite and crystalline limestone containing primary sphalerite and pyrrhotite suggests that the initial concentration of metals in this area can be traced back to a period prior to the Hida metamorphism. The K-Ar ages of sericites represent the time when the deposits took the present form.

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Two-dimensional frequency distribution of geochemical data was determined by computation of two-dimensional cumulative frequency and its partial differentiation with respect to two variables without any assumption on the type of statistical distribution of data.
The technique was applied to actual geochemical exploration data, which proved the superiority of twodimensional distribution to one-dimensional distribution for defining geochemical anomalies and partitioning a composite population into constituting single populations.
Characteristics of two-dimensional normal distribution and apparent correlation in a composite population were also briefly discussed.

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