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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 3
Displaying 1-7 of 7 articles from this issue
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Tsunehiko Takeuchi, Matsuo Nambu1958 Volume 42 Issue 3 Pages 101-104
Published: June 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSCubanite occurs in the contact-metasomatic No.2 Shinyama copper deposit of Kamaishi Mine. The lump cubanite is observed abundantly in paragenesis with pyrrhotite, chalcopyrite and pentlandite, more rarely with pyrite, sphalerite and vallerite, and often intimately intergrown with chalcopyrite, pentlandite, pyrrhotite and sphalerite due to the unmixing of solid solution between them. The chemical analysis gives: Cu 23.30; Fe 41.23; S 34.81; Ni 0.11; Zn O.03; SiO2 0.51, and the X-ray powder data were given.View full abstractDownload PDF (771K) -
Ryohei Ota1958 Volume 42 Issue 3 Pages 104-114
Published: June 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSContamination phenomena observed in pyroxene andesite are considered as follows: 1. Existence of xenocrysts of quartz, sodic plagioclase, biotite, hornblende, etc. 2. Existence of xenolithes which remarkably reacted with magma. 3. Existence of anorthite large crystals. In this paper, the writer has added the following phenomena: 4. Spherical patch filled up with quartz in groundmass (PA). 5. Parallel-growth of pyroxene containing hypersthene inside and augite outside (P). 6. Glome-ro-porphyritic aggregate composed of hypersthene, angite, plagioclase, magnetite, etc. (G).View full abstractDownload PDF (1253K) -
Jun-ichi Kitahara1958 Volume 42 Issue 3 Pages 114-128
Published: June 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSGranite, granite porphyry and quartz porphyry were originated from same magma in the Tari district. It seems probably that ultrabasic rocks were intruded in Palaeozoic formation in the region. The ultra-basic rocks consist largely of serpentinized dunite and harzburgite. Serpentinite associated with disseminated chromite is generally pale yellow or pale green and wall rock serpentinite is dark green or black. The variation in forsterite content for the ultra-basic rocks tested by the writer is Fo92-97 mo1ecu1ar percent. Iron oxide content in ultra-basic rock is rather low and magnesia content predominates over iron oxide content. Enstatite has sometimes altered to bastite and olivine to mesh serpentine. Serpentinized olivine is ophitically held in enstatite or bastite altered from enstatite. It seems that serpentinization come from within the ultra-basic rock (so-called autometamorphism) and serpentine is not crystallize directly from the residual liquid. Dusty magnetite is separated in serpentine derived from forsterite, but a part of iron still remains in the serpentine. Serpentinized ultra-basic rocks have a higher Fe2O3/FeO ratio than unserpentinized ultra-basic rocks as shown in Table of the chemical analyses.
Gabbros occur within the serpentinites and chromite bodies as cognate xenolith derived from the same magma that generated ultra-basic rockss and chromites. Uralite was produced around the periphery by the alteration of clinopyroxene. The optical properties and chemical compositions of the gabbros are described.View full abstractDownload PDF (1816K) -
Yôtarô Seki1958 Volume 42 Issue 3 Pages 128-135
Published: June 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSRegarding to the chemical composition of alkali-amphiboles, the Sanbagawa metamorphic rocks in the eastern part of the Kantô Mountains can be divided in the descending order into the following four zones:
A zone: Subglaucophane, riebeckite, magnesioriebeckite
B zone: Glaucophane proper
C zone: Subglaucophane, riebeckite, magnesioriebeckite
D zone: Magnesioriebeckite (unstable)
In this paper, optical and chemical properties and modes of occurrence of the alkali-amphiboles are described in some detail.View full abstractDownload PDF (426K) -
Sadao Higashimoto1958 Volume 42 Issue 3 Pages 136-144
Published: June 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSGojo mine is situated in the so-called undetermined Mesozoic formation which is consisted of shale, sandstone, tuff, chert, diabase and limestone. The ore bodies are lenticular in shape, and are consisted of pyrite, melnicovite-pyrite, chalcopyrite, sphalerite, galena, quartz and chlorite. The ore bodies and the country rocks are remarkably sheared, and the most part of the ores are cataclastic in texture, but there are some ores which are colloidal in texture in the inner part of the ore bodies where shearing is not so remarkable. The colloidal texture is pre-tectonic (pre-cataclastic).
The colloidal ores show radial, concentric and spherical arrangement, are mainly consisted of melnicovite-pyrite associated with some sphalerite, chalcopyrite, pyrite, quartz and chlorite. The ores must be formed by coagulation or precipitation of the dispersed phase from the disperse system.
The geological agitation in this case might be volcanism, and the dispersion medium might be sea water or brackish water which contains sufficient amount of electrolyte to coagulate the sulphidesol. The source of the materials of the ore deposits is also the volcano, and the deposits are probably syngenetic in origin.View full abstractDownload PDF (1662K) -
Fumio Kuramochi1958 Volume 42 Issue 3 Pages 145-151
Published: June 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSDownload PDF (742K) -
Koiti Suzuki, Umeka Kitazaki1958 Volume 42 Issue 3 Pages 152-160
Published: June 01, 1958
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSIn muddy rocks of the upper Ishikari group of the Sorachi coal field, halloysite, montmorillonite, illite and mixed layers of montmorillonite and illite occur almost always in association with one another.
The lower Corbicula-bearing, Woodwardia and upper Corbicula-bearing formations are characterized by frequent occurrences of samples richer in 3-layer clay minerals, i.e. montmorillonite, illite and their mixed layers. No such sample has been found in the Ashibetsu formation, except its basal part in Ashibetsu district. In this district, the upper part of the formation is showing frequent occurrences of samples richer in halloysite of 2-layer structure.
A probable correlation is suggested between this stratigraphical change in clay mineral composition and that found in the lower part of the Ikushunbetsu formation of the Yübari coal field.View full abstractDownload PDF (776K)
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