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Volume 42 (1958)
- Issue 6 Pages 261-
- Issue 5 Pages 207-
- Issue 4 Pages 161-
- Issue 3 Pages 101-
- Issue 2 Pages 53-
- Issue 1 Pages 1-
Volume 42, Issue 6
Displaying 1-7 of 7 articles from this issue
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Iichiro Takahashi1958 Volume 42 Issue 6 Pages 261-271
Published: December 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSThe sulphur deposit of the Narugo mine is mainly muddy sediment on the bottom of a lake on the top of a volcano, which is accompanied by several minor deposits of sublimation and impregnation types. Muddy deposit occurs partly in minute laminae and partly in lenticular or irregular bodies. It is so fine-grained and muddy that some special treatments are necessary for its mining and extraction, for which the knowledge of its mineral paragenesis is desirable. The present study is made for this purpose with the following results.
Infered from the results of microscopic, electron-microscopic, chemical, differential thermal and X-ray studies, the ore consists of sulphur and pyrite, associated with, enumerated in decreasing order, kaolinite, halloysite, glassy fragments, pumice, quartz, silicified rock, opal, cristobalite, montmori-llonite, diatom crust, sericite, alunite, plagioclase, limonitic material, a titanium mineral and hypersthene.
The most part of the ore has been formed by free chemical precipitation but some minor portion by impregnation. This is infered from the evidence of replacement of some other minerals and rock fragments by sulphur and pyrite.
Some relations of the ore paragenesis to its mining, dressing and smelting are also mentioned.View full abstractDownload PDF (1140K) -
Toshiaki Suzuki1958 Volume 42 Issue 6 Pages 272-279
Published: December 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSRing ores occur in many volcanic sulphur deposits which are mainly composed of iron sulphides. These ring ores can be classified into two types, lava type and shale type, on the basis of their mode of occurences and structural characters.
Lava type is widely found, and it has been reported that such ores were formed by the Liesegang´s phenomenon.
Aaccording to the present studies it can be believed that these rings were formed by the replacement along the onion-like cracks.
The shale type is found rarely, and it seems that these rings were formed by the inward diffusion of the reacting solution.View full abstractDownload PDF (1053K) -
Keiichi Omori, Shuzo Hasegawa1958 Volume 42 Issue 6 Pages 280-284
Published: December 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSMain constituent minerals of the pegmatite are microcline perthite, plagioclase, quartz, muscovite and tourmaline. A considerable amount of platy crystal of ilmenite, sometimes attaining to 10cm in diameter and 1cm in thickness, occurs associating with pinkish microcline perthite of which composition is represented as Or68.1 Ab31.4 An0.5. Euxenite, less than 1×3mm in size, is found in close association with ilmenite. The results of chemical analyses of ilmenite and euxenite are shown in the table 2 and 4 respectively. Ilmenite has excessive amounts of Fe2O3 and Ti02 which were derived from the mingling of unmixing hematite and titania mineral (rutile ?). The chemical formula of euxenite is calculated as (Ca0.10 Mn0.01 Th0.02 Ce0.04 Y0.54 U0.16 Fe+20.12)0.99 (Mg0.03 Fe+30.05 Al0.02 Ti1.20 Nb0.43 Ta0.25 Si0.08)2.06 (0, OH)6.34.View full abstractDownload PDF (755K) -
Ryohei Ota1958 Volume 42 Issue 6 Pages 285-295
Published: December 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSDownload PDF (695K) -
Yôtarô Seki1958 Volume 42 Issue 6 Pages 296-301
Published: December 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSThe regional metamorphism which produces glaucophanites can be regarded as metamorphism under low temperature and high pressure. It has been expressed by many authors including the present writer that the glaucophanites have no special characteristics in the chemical composition.
However, it is evident from the statistical study of the available chemical data that the metamorphic rocks, especially the green schists in the glaucophanitic regional metamorphic terrains have generally higher content of Na2O and higher ratio of Fe2O3: FeO than the metamorphic rocks subjected to other types of regional metamorphism. These features are considered to be due to the soda-metasomatism and rather high water vapour pressure prevailing in some glaucophanitic regional metamorphic terrains.View full abstractDownload PDF (311K) -
Hitoshi Momoi1958 Volume 42 Issue 6 Pages 302-308
Published: December 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSThe determination of radium was made by the solution method, using the ionization chamber. The samples were collected from six granite bodies in Kyushu: Tsushima, Okue-yama, Ichifusa-yama, Shibisan, Takakuma-yama, and Osumi granite bodies.
All of these bodies, which are composed exclusively of fine-grained biotite granite containing dark or light brownish-red or reddish-brown zircons, are intruded into Paleozoic or Mesozoic sediments accompanied by both thermo-metamorphic effect and pneumatolytic ore deposits on their north or south side, showing small circular exposures from 4 to 10km in diameter.
As regards radium content, the Tertiary granites investigated are distinguished from older granites by the following characters:
(1) The Tertiary granites are richer in radium than older ones; (2) The mean radium content of each Tertiary or Cretaceous granite body generally increases with increasing silica, while that of each Permo Triassic Ryoke granite body tends to decrease; (3) As to an individual granite body, the radium content of Cretaceous granite varies sympothetically with silica, but that of the Ryoke granite is in antipathetic relation to silica. Such relations between radium and silica contents cannot clearly been perceived in any Tertiary granite body, because there observed little variation of silica if present; (4) The orders of intrusion of the Ryoke and Cretaceous granites have been known well: the former granite shows the tendency that radium is more concentrated in younger intrusions, while the latter in the older. In the case of the Tertiary granites, however, the order of intrusion has not yet been decided.View full abstractDownload PDF (330K) -
Nobuhide Murakami1958 Volume 42 Issue 6 Pages 309-318
Published: December 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSSome types of syenite are found in granitic rocks in southwestern Japan. They are devided into four types, A, B, B', and C, according to the combination of principal minerals. Type A is potash-syenite, bearing hornblende or biotite as principal minerals. Type B is composed mainly of pyroxene, hornblende, andradite, and albite with often relict of potash-feldspar, while principal minerals in B are epidote, albite and potash-feldspar. Type C is characterized by epidote, chlorite, albite and/or potash-feldspar.
By field occurence and textural relation, the genesis of these syenites can be attributed to the metasomatic acition of alkali-emanation, eliminated as volatile vapor from the deeper granitic magmas. So, Type C might be produced either in shallower regions or in lower temperatures in deuteric stage, than A and B. Type A and C can be found in normal granitic rocks, but the source of emanation in B might be more alkaline magma which represent the more advanced stage of granitic evolution, as thought in replacement pegmatite. The relationship in four rock types is shown in Figure 8.View full abstractDownload PDF (408K)
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