Journal of Mineralogical and Petrological Sciences
Online ISSN : 1349-3825
Print ISSN : 1345-6296
Volume 113 , Issue 1
February
Showing 1-8 articles out of 8 articles from the selected issue
EDITORIAL BOARD
  • 2018 Volume 113 Issue 1 Pages 113H2
    Published: 2018
    Released: March 01, 2018
    JOURNALS FREE ACCESS

    Official journal of Japan Association of Mineralogical Sciences (JAMS), focusing on mineralogical and petrological sciences and their related fields. Journal of Mineralogical and Petrological Sciences (JMPS) is the successor journal to both "Journal of Mineralogy, Petrology and Economic Geology" and "Mineralogical Journal". Journal of Mineralogical and Petrological Sciences (JMPS) is indexed in the ISI database (Thomson Reuters), the Science Citation Index-Expanded, Current Contents/Physical, Chemical & Earth Sciences, and ISI Alerting Services.

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ORIGINAL ARTICLES
  • Kazuhiro SUZUKI, Masaki ENAMI, Hirokazu MAEKAWA, Takenori KATO, Tomoko ...
    2018 Volume 113 Issue 1 Pages 1-9
    Published: 2018
    Released: March 01, 2018
    [Advance publication] Released: December 27, 2017
    JOURNALS FREE ACCESS

    The Sanbagawa metamorphic rocks of epidote–amphibolite facies are extensively exposed in Nushima at the southern end of the Hyogo Prefecture, Japan. Chemical U–Th–total Pb isochron method (CHIME) ages were determined for monazite grains from the Sanbagawa metamorphic rocks. CHIME monazite ages are 92.3 ± 3.2 and 90.3 ± 4.7 Ma for two chlorite–rich rocks collected from the reaction zone between pelitic schists and serpentinites. The monazite grains occur as isolated phases or aggregates with rutile/ilmenite in chlorite–rich matrix, and thus the CHIME monazite ages are interpreted to represent recrystallization close to the peak stage of prograde epidote–amphibolite facies metamorphism. Considering the U–Pb zircon ages reported in literature, the main stage of Sanbagawa prograde metamorphism up to the epidote–amphibolite facies is estimated to have been at 80–92 Ma. Comparison of the age data between the Sanbagawa eclogite and epidote–amphibolite facies stages suggests the possibility that the formation of eclogite facies rocks at different depths and periods of the Sanbagawa subduction continued for more than 20–30 million years.

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  • Zuozhen HAN, Zhigang SONG, Chao HAN, Wenjian ZHONG, Mei HAN, Junlei YA ...
    2018 Volume 113 Issue 1 Pages 10-23
    Published: 2018
    Released: March 01, 2018
    [Advance publication] Released: February 06, 2018
    JOURNALS FREE ACCESS

    The Changchun–Yanji suture in Jilin Province, NE China is generally interpreted to mark the closure position of the Paleo–Asian Ocean along the north margin of the North China Craton. However, the issue about the early–middle Paleozoic tectonic evolution in this region has long been debated. In order to provide evidence for resolving this issue, we carried out a geochemical and zircon U–Pb–Hf study on the Fangniugou and Taoshan volcanic rocks from the Fangniugou area of Jilin Province, in the Changchun–Yanji suture zone. Laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) zircon U–Pb dating indicates that the Fangniugou volcanic rocks are products of at least two volcanic events (∼ 425 and 390 Ma) and that episodes of magmatism existed in Jilin Province during the early–middle Paleozoic period. These rocks, in conjunction with relevant data from the literature, indicate that early–middle Paleozoic magmatism occurred along the Changchun–Yanji suture. The volcanic rocks belong to medium– to high–K calc–alkaline series and display features of I–type granites of subduction–related igneous rocks. During the late Silurian–middle Devonian, the Y and Yb concentrations progressively decreased with time, accompanied by an increase in K2O concentrations and (La/Yb)N values, indicating a process of crustal thickening. This interpretation is supported by the presence of early Paleozoic arc igneous rocks and the formation of early Devonian molasse in central Jilin Province. Zircon grains separated from the rocks have high εHf(t) values and two–stage Hf model (TDM2) ages varying from +4.92–8.76 and 0.84–1.09 Ga, respectively. All these characteristics, in conjunction with trace element features, suggest that the late Silurian rocks were generated by partial melting of a depleted mafic lower crust in a subduction zone setting, whereas the middle Devonian rocks were derived from partial melting of a thickened lower crust the most probably related to a collisional event.

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  • Hongbin LI, Daizo ISHIYAMA, Yu ZHANG, Yongjun SHAO
    2018 Volume 113 Issue 1 Pages 24-40
    Published: 2018
    Released: March 01, 2018
    JOURNALS FREE ACCESS

    The Xiajinbao gold deposit is located in the Yanshan District of the North China Craton. The geology of the Xiajinbao deposit consists of Archean gneiss, Proterozoic sedimentary rocks, granite porphyry, quartz porphyry dikes, and diorite dikes. The diorite contains a large quantity of magnetite. The granite porphyry and quartz porphyry dikes, which contain trace amounts of ilmenite without magnetite, have high aluminum saturation index values and a low magnetic susceptibility. These rocks are classified as ilmenite series granitic rocks. The pyrite quartz veins (Stage I), pyrite–chalcopyrite quartz veins (Stage II), and sphalerite–galena quartz veins (Stage III) of the Xiajinbao deposit were hosted in the granite porphyry. Major gold mineralization was associated with the sphalerite–galena quartz veins. The homogenization temperature and salinity of the sphalerite–galena quartz veins are 220 °C in a mode and 9.1–13.8 wt%, respectively. The sulfur fugacity of the Xiajinbao deposit ranged 10−7.8–10−11 and 10−9.5–10−14.3 atm for the pyrite–chalcopyrite quartz veins and sphalerite–galena quartz veins, respectively. The formation environment of the sphalerite–galena quartz veins of the Xiajinbao deposit is similar to that of zoned base metal veins associated with oxidized magma. The oxygen and hydrogen isotope ratios of the hydrothermal solution in equilibrium with quartz from the sphalerite–galena quartz veins range from +3.3 to +5.5 and −38 to −41‰, respectively, suggesting magmatic water. The range of sulfur isotope ratios of pyrite and galena from the sphalerite–galena quartz veins is from −0.2 to +3.6‰. These sulfur isotope ratios are in the range of ratios for ores formed by igneous activity associated with oxidized magma. Therefore, the gold mineralization of the Xiajinbao deposit is inferred to be the result of igneous activities from oxidized magmas, such as the diorite dikes, with the granite porphyry forming the host rock of the sphalerite–galena quartz veins of the Xiajinbao deposit.

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LETTERS
  • Masami KANZAKI
    2018 Volume 113 Issue 1 Pages 41-46
    Published: 2018
    Released: March 01, 2018
    [Advance publication] Released: December 12, 2017
    JOURNALS FREE ACCESS

    Crystal structures of the cubic and tetragonal spinel phases of Zn2GeO4 and the modified spinel phase of Zn2SiO4 were refined by Rietveld analysis of synchrotron powder X–ray diffraction data. The Zn2GeO4 cubic spinel phase was found to have an inverse spinel configuration. The Zn2GeO4 tetragonal spinel phase is isostructural to Zn2TiO4, where half of Zn occupies the tetrahedral site, and the remaining Zn and Ge are ordered in two octahedral sites. In the modified spinel phase of Zn2SiO4, Zn occupies the octahedral sites. Independent individual cation–oxygen distances in the Zn2GeO4 tetragonal spinel and Zn2SiO4 modified spinel phases were calculated using the bond valence repartition method, and are in reasonable agreement with the refined structures.

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  • Akio SUZUKI
    2018 Volume 113 Issue 1 Pages 47-50
    Published: 2018
    Released: March 01, 2018
    [Advance publication] Released: February 06, 2018
    JOURNALS FREE ACCESS

    Viscosity is one of the important transport properties controlling the migration of magma in the Earth’s interior. Experimental and geochemical studies have shown that magma is generated in the deep interior in the presence of CO2. However, our knowledge of the effect of CO2 on the viscosity of magma (silicate melt) is limited. In this work, the viscosity of a molten jadeite composition containing 0.5 wt% CO2 was measured under high pressure. We observed that in the presence of CO2, the viscosity was one to two orders of magnitude lower than without CO2.

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  • Takahiro KURIBAYASHI, Satoshi AOKI, Toshiro NAGASE
    2018 Volume 113 Issue 1 Pages 51-55
    Published: 2018
    Released: March 01, 2018
    JOURNALS FREE ACCESS

    In–situ high–temperature single–crystal X–ray diffraction experiments on modulated haüyne obtained from Eifel, Germany, were conducted to re–evaluate its thermal behavior. The linearity of its thermal expansion is lost between 600 and 700 °C. Satellite peaks, indicating the modulated structure, were clearly observed up to 600 °C, but disappeared at 700 °C. These results indicate that the modulated haüyne structure changed in this temperature region. In addition, according to the observation of X–ray oscillation images taken at ambient conditions, the modulated structure of the sample heat–treated below 1000 °C remained unchanged, whereas modulation of the parent crystal structure changed when the sample was heat–treated above 1000 °C. This structural change to the unique modulated structure can be attributed to be the possible rearrangement of Al/Si distribution in the tetrahedral sites forming the framework.

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INSTRUCTIONS FOR CONTRIBUTORS
  • 2018 Volume 113 Issue 1 Pages 56-57
    Published: 2018
    Released: March 01, 2018
    JOURNALS FREE ACCESS

    Manuscripts to be considered for publication in the Journal of Mineralogical and Petrological Sciences should be original, high-quality scientific manuscripts concerned with mineralogical and petrological sciences and related fields. Submitted papers must not have been published previously in any language, and author(s) must agree not to submit papers under review in the Journal of Mineralogical and Petrological Sciences to other journals. The editorial board reserves the right to reject any manuscript that is not of high quality and that does not comply with the journal format outlined below. The editorial board is keen to encourage the submission of articles from a wide range of researchers. Information on submitting manuscripts is also available from the journal web site (http://jams.la.coocan.jp/jmps.htm)

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