The Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists
Online ISSN : 1883-0765
Print ISSN : 0021-4825
ISSN-L : 0021-4825
Search
Advanced search
OR
Browse
Search
Volume 78, Issue 4
Displaying 1-4 of 4 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • Flux growth of potassium-priderite single crystals
    YOSHINORI FUJIKI, TAKAYOSHI SASAKI, MICHIKO KOBAYASHI
    1983 Volume 78 Issue 4 Pages 109-114
    Published: April 05, 1983
    Released on J-STAGE: August 07, 2008
    DOIhttps://doi.org/10.2465/ganko1941.78.109
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Potassium-priderite single crystals, a one-dimensional ionic conductor, were grown by the slow cooling technique from a flux melt of the system K2MoO4-MoO3. Single crystals with Li+ or Na+ ions replacing partially potassium sites were also grown.
    Chemical analysis, lattice parameters, infrared spectra, crystal habit and surface observations of these crystals are described.
    View full abstract
    Download PDF (1647K)
  • Fe-Mg partitioning between spinel and olivine
    AKIRA ONO
    1983 Volume 78 Issue 4 Pages 115-122
    Published: April 05, 1983
    Released on J-STAGE: August 07, 2008
    DOIhttps://doi.org/10.2465/ganko1941.78.115
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Partitioning of Fe and Mg between spinel and olivine was studied as a function of temperature. Spinel-olivine geothermometer was revised on the basis of new experimental data. Experiments were performed in Cr-free and Al-free systems separately. Partition coefficient K'(K'=(Fe/Mg)sp/(Fe/Mg)ol) is determined as follows:
    ln K1'=0.057/T•104+0.102
    ln K2'=0.397/T•104-0.832
    where K1' and Ka2' are partition coefficients of Cr- free and Al-free systems, respectively, and T is absolute temperature. The equations are significant in the case where olivine is within compositional range of Fa10-20 and pressure is 10.5 kbar. The uncertainty of estimated temperature is about ±70°C. Effect of Fe+3 content in spinel on ln K' is small in the Al-free system.
    View full abstract
    Download PDF (530K)
  • Petrology of the felsic volcanic rocks from Usu Volcano, Hokkaido, Japan
    Yoshio Oba, Yoshio Katsui
    1983 Volume 78 Issue 4 Pages 123-131
    Published: April 05, 1983
    Released on J-STAGE: August 07, 2008
    DOIhttps://doi.org/10.2465/ganko1941.78.123
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The historic felsic rocks of Usu Volcano vary from rhyolite to dacite with time, decreasing in silica. Consistent with such a change in bulk chemical compositions of the felsic rocks, normal plagioclase phenocrysts become more calcic and orthopyroxene more magnesian. This evidence can be interpreted in terms of a compositionally zoned felsic magma chamber with silica increasing upwards, which formed prior to the first historic Plinian eruption in 1663. In addition to the above phenocrysts, a small amount of calcic plagioclase, magnesian orthopyroxene, augite and pargasitic hornblende which seem to be disequilibrium with the felsic magma, are included. The process of incorporation of these crystals into the felsic magma and the formation of the zoned magma chamber are discussed.
    View full abstract
    Download PDF (648K)
  • [title in Japanese]
    1983 Volume 78 Issue 4 Pages 132-152
    Published: 1983
    Released on J-STAGE: July 13, 2012
    DOIhttps://doi.org/10.2465/ganko1941.78.132
    JOURNAL FREE ACCESS
    Download PDF (2262K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top