Journal of Mineralogical and Petrological Sciences
Online ISSN : 1349-3825
Print ISSN : 1345-6296
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Volume 107 , Issue 4
August
Showing 1-4 articles out of 4 articles from the selected issue
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ORIGINAL ARTICLES
  • Naotaka TOMIOKA, Andreas MORLOK, Chiyoe KOIKE, Melanie KÖHLER, Mo ...
    Volume 107 (2012) Issue 4 Pages 157-166
    Released: September 01, 2012
    JOURNALS FREE ACCESS
    In situ mid-infrared transmission measurements of matrices from carbonaceous chondrites heated up to 572 °C in air were conducted by FTIR spectroscopy. The FTIR spectra of the matrices mainly showed olivine bands. With increasing temperature, up to 477 °C, the spectra did not show significant changes. However, at 572 °C, the ~11-μm band split into a doublet, and the intensity of the ∼ 10-μm band relative to that of the ∼ 11-μm band increased significantly. In synthetic Fe-rich olivine (Fo47) samples heated at 600 °C in air, their mid-infrared spectra showed changes similar to those in meteoritic samples. A TEM observation of the recovered meteoritic samples showed that most olivine grains had a stacking disorder on (001). Selected area electron diffraction patterns of the grains also exhibited extra reflections, corresponding to a similar superstructure to three-fold periodicity along col known as laihunite-3M in Fe2SiO4. Although the synthetic Fe-rich olivine did not have any defect structures before heating, the olivine commonly had a stacking disorder on (001) after heating at 600 °C. Therefore, the changes in mid-infrared spectra of the matrices of carbonaceous chondrites were not caused by chemical reactions among their constituent minerals, but were mainly caused by oxidation of iron within the olivine structure. The mid-infrared spectra of olivine-dominating samples from this study are potential reference data for the oxidation state of olivine in in situ mid-infrared measurements on the Martian surface, in partially oxidized meteorites, on asteroidal surfaces, and in interplanetary dust particles.
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  • Yasuyuki BANNO, Shigeo YAMADA
    Volume 107 (2012) Issue 4 Pages 167-172
    Released: September 01, 2012
    JOURNALS FREE ACCESS
    Sector-zoned aegirine was found in a specimen of Sanbagawa quartz schist from the Iimori region of the western Kii Peninsula, central Japan. The schist consists of quartz, aegirine, albite, amphibole (magnesioriebeckite to manganocummingtonite), garnet (spessartine), rhodochrosite, pyrophanite, jacobsite, and apatite. Aegirine occurs as subhedral to euhedral prismatic crystals less than 250 μm long. Three sectors in the zoning are distinguished on the basis of backscattered electron images. The [001] sector is more enriched in Ca and Mg (as CaMgSi2O6) and depleted in Al (as NaAlSi2O6) than the {110} and {100} sectors, and the {110} sector is more enriched in Fe3+ (NaFe3+Si2O6) and depleted in Al than the {100} sector. The sector-zoned aegirine is mantled by XJd-rich aegirine, and there is an outermost rim of XJd-poor aegirine. These textural relationships suggest that after rapid non-equilibrium crystallization, the XJd-rich mantle as well as the XJd-poor outermost rim formed under conditions of equilibrium with the surrounding minerals.
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TECHNICAL NOTE
  • Masaki ENAMI
    Volume 107 (2012) Issue 4 Pages 173-180
    Released: September 01, 2012
    JOURNALS FREE ACCESS
    Raman spectra of five natural garnet grains with compositions close to those of the endmember species almandine, spessartine, pyrope, grossular, and andradite were measured. Spectral data for the garnet grains are used to study the interference with the three intense peaks from quartz (labeled as Q01, Q02, and Q03 in order of decreasing wavenumber) that are usually employed in quartz Raman barometry. The peaks from grandite garnet do not interfere with these three peaks from quartz. The pyralspite garnet spectrum has a clear peak at 209-221 cm-1 that significantly interferes with the Q02 peak from quartz. Quartz Raman barometry is usually applied to a quartz inclusion in a garnet host. To avoid interference of the host garnet spectrum on the quartz Raman barometry results, it is strongly recommended that spectra with less intense garnet peaks are considered, e.g., with IG05 < IQ02, where IG05 and IQ02 denote the normalized intensities of the most intense peak from the pyralspite garnet (labeled G05) and the Q02 peak from quartz, respectively.
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Errata
  • Volume 107 (2012) Issue 4 Pages 181
    Released: September 01, 2012
    JOURNALS FREE ACCESS
    The following are errata for the original article entitled “Miyahisaite, (Sr,Ca)2Ba3(PO4)3F, a new mineral of the hedyphane group in the apatite supergroup from the Shimoharai mine, Oita Prefecture, Japan” by the Daisuke NISHIO-HAMANE, Yukikazu OGOSHI and Tetsuo MINAKAWA (Vol. 107, no. 3, 121-126, 2012). These are authors' mistakes.

    Page 121, Abstract line 7; 100.00 wt% should be read as 99.99 wt%
    Page 123, CHMICAL COMPOSITION line 20; 100.00 wt% should be read as 99.99 wt%.
    Page 123, Table 1, Total 7.997 should be read as 7.996.
    Page 124, Table 2 in hkl list, line12, 115 and line 13, 600 should be read as 600 and 115, respectively.
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