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Volume 23 (1983)
- Issue 4 Pages 131-
- Issue 3 Pages 87-
- Issue 2 Pages 39-
- Issue 1 Pages 1-
Volume 23, Issue 1
Displaying 1-5 of 5 articles from this issue
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Susumu SHIMODA1983 Volume 23 Issue 1 Pages 1-6
Published: March 25, 1983
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSThe name of mica clay mineral is used widely in mineralogy, petrology and geology, although the mineral has not been defined mineralogically. Mica clay mineralsappeared in the literature have many characteristics, and so that many names are given to the minerals as a species and/or group names. This seems to lead some mineraloglogical confusions in the mineral description. Nomenclature for the minerals has many difficulties mineralogically, because the minerals are formed easely from other minerals by alteration and easely change to other minerals in natural conditions.
Logical discussions for the definition and nomenclature of the minerals are imposible in this paper, but it seems to be better that the term is used as a general name for some mica minerals, which are possible to become a clay mineral, when they are a main constituent mineral of a clay. If not, they are merely a mica mineral, not a mica clay mineral. If the mineral is defined as this, the name of the mineral should be given on the basis of the nomenclature of minerals.
Mode of occurrence has been described in many ways. Though the mode of occurrence seems to show only the form of a mineral aggregation found in nature, the description should show the form of the mineral assemblage from the concept of the genesis.View full abstractDownload PDF (3059K) -
Shingo ISHIDA, Yoshikazu FUJIMURA, Kaichi FUJIYOSHI, Shigeto KANAOKA, ...1983 Volume 23 Issue 1 Pages 7-17
Published: March 25, 1983
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSThe behavior of Fe ions contained in kaolinite and sericite during the firing at110-1300°C in air was studied mainly by ESR.
On increasing the firing temperature of kaolinite, the intensity of the signal due to (strongly) magnetic iron oxides grew to a maximum at 600°C and decreased above 600°C whereas that of isolated Fe3+ ion (g=4.25) increased above 600°C. The quantity of bulky iron oxides was roughly proportional to the intensity of the signal due to (strongly) magnetic iron oxides.
The percentage of the soluble Fe ions to the total Fe ions in the kaolinite body on the elution treatment with a dilute oxalic solution was also roughly proportional to the intensity of the signal due to (strongly) magnetic iron oxides. In the case of the fired sericite, ESR signal due to bulky iron oxides was comparatively weak and the percentage of the soluble Fe ions to the total Fe ions was found to be low on the elution treatment.
Chemical analyses of Fe2+ and Fe3+ in the sericite bodies fired at various temperatures and measurements of the intensities of the signal at g=4.25 in their spectra revealed that only a part of the isolated Fe3+ was observable by ESR. The presence of Fe3+ unable to observe by ESR indicates that ESR is generally inapplicable to the quantitative analysis of Fe3+ in clay.
The line width of the signal at g=4.25 observed in the kaolinite body decreased after the dehydration at 500°C and increased after the firing at 1000°C. Similar changes of this Fe3+ signal were also found in the case of the sericite body. Primitive speculations were made on the relations between structural changes of kaolinite and sericite and spectral changes of the isolated Fe3+ and bulky iron oxides.View full abstractDownload PDF (1367K) -
Joyo OSSAKA, Jun-ichi HIRABAYASHI, Kiyoshi OKADA, Shoji FUTAKI1983 Volume 23 Issue 1 Pages 17-26
Published: March 25, 1983
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSChemical and mineralogical changes of volcanic ash beds which were erupted from the Volcano Ontake around Ina district, Nagano Prefecture by weathering were examined by means of the chemical analysis, X-ray powder diffraction, differential thermal analysis and grain size distribution analysis. In the Middle Loam unit, clay mineral formed by weathering was mainly allophane in the pumice beds of Pm-II, II', III, whereas it was mainly halloysite 10Å in the Pm-I and the other loam beds. In the Younger Loam unit, clay mineral formed was mainly allophane and halloysite 10Å was not observed. By weathering the compositions of SiO2, CaO, MgO, Na2O and K2O decreased, whereas those of 2O3 and ΣFe2O3 increased by the relative condensation, and H2O increased by the formation of clay minerals. It was found in the chemical composition changes of SiO2, Al2O3 and ΣFe2O3 that SiO2 and ΣFe2O3 leached and Al2O3 relatively condensed in the lower part of the outcrop, whereas SiO2 leached and Al2O3 and ΣFe2O3 relatively condensed in the middle and upper parts. These chemical changes were understood by assuming the existences of reducing, intermediate and oxidizing zones by the reaction of underground water and/or by considering the changes of the chemical compositions of the host rocks from rhvolitic to andesitic.View full abstractDownload PDF (1167K) -
Kiyoshi OKADA, Joyo OSSAKA1983 Volume 23 Issue 1 Pages 27-31
Published: March 25, 1983
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSDehydration mechanism of interlayer water of halloysite heated at various temperatures was investigated by X-ray powder diffraction and weight loss analysis. Itwas found that halloysite 10Å changed to halloysite 7Å coherently and they were segregated each other during the dehydration. The idealized structure model in which dehydration progressed preferably perpendicular to the layers of each crystallite was considered. Reaction above 55°C was able to be approximated by the zero order which was expected from the above dehydration model, whereas it was influenced by the diffusion from the inner part of the particles formed by gathering many crystallites below 55°C. The activation energies obtained from the data of the temperature above and below 55°C were 6.8 and 11.9Kcal/mol, respectively.View full abstractDownload PDF (607K) -
Selective chemical dissolution-difference IR absorption spectroscopyNaganori YOSHINAGA, Chitoshi MIZOTA, Makoto NAKAI1983 Volume 23 Issue 1 Pages 31-37
Published: March 25, 1983
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSDownload PDF (951K)
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