H. Mori, T. Tokiwa, Hiroki Mizumura, Kohei Yoshikawa, Y. Nobe, Y. Kouketsu
{"title":"Protolith age and metamorphic temperature of the Yokokawagawa metamorphic rocks in Nagano Prefecture, central Japan, and comparison with the Sanbagawa metamorphic rocks","authors":"H. Mori, T. Tokiwa, Hiroki Mizumura, Kohei Yoshikawa, Y. Nobe, Y. Kouketsu","doi":"10.2465/jmps.221215","DOIUrl":"https://doi.org/10.2465/jmps.221215","url":null,"abstract":"","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68832860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Baba, Prayath Nantasin, A. Kamei, Ippei Kitano, Y. Motoyoshi, N. Setiawan, Davaa-ochir Dashbaatar, T. Hokada
{"title":"Counter-clockwise P-T history deduced from kyanite-bearing pelitic gneiss in Tenmondai Rock, Lützow-Holm Complex, East Antarctica","authors":"S. Baba, Prayath Nantasin, A. Kamei, Ippei Kitano, Y. Motoyoshi, N. Setiawan, Davaa-ochir Dashbaatar, T. Hokada","doi":"10.2465/jmps.221202","DOIUrl":"https://doi.org/10.2465/jmps.221202","url":null,"abstract":"","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68833166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Boron isotope compositions of coexisting kornerupine and tourmaline in high-grade metabasic rocks: an example from Akarui Point, Lützow-Holm Complex, East Antarctica","authors":"Tetsuo Kawakami, S. Harley","doi":"10.2465/jmps.230131b","DOIUrl":"https://doi.org/10.2465/jmps.230131b","url":null,"abstract":"","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68833341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Crystal structures of anhydrous borax α-Na2B4O7 and γ-Na2B4O7 and ab initio quantum chemical calculations of structural stability on their fundamental building blocks","authors":"Wataru Nishiyasu, A. Kyono","doi":"10.2465/jmps.230112","DOIUrl":"https://doi.org/10.2465/jmps.230112","url":null,"abstract":"","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68833468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Asagiite, a newly-discovered mineral having the ideal formula NiCu4(SO4)2(OH)6·6H2O, is a member of the ktenasite group, representing a Ni analogue. It occurs as a secondary mineral on smithsonite aggregates that overlie fractures in a serpentinite found in the Nakauri mine within Aichi Prefecture, Japan. Asagiite exhibits a unique pale blue-green coloration and so is named after the traditional Japanese color “asagi-iro.” Asagiite occurs as thin plate-like crystals with perfect cleavage along {001} planes. The crystal size of this mineral is typically 0.1 to 0.2 mm, although in rare cases crystals may range up to 0.5 mm in length. These crystals are vitreous, transparent and non-fluorescent and have also been shown to be brittle with a Mohs hardness of 2½. The measured and calculated densities of asagiite are 2.90(3) and 2.92 g·cm-3, respectively. This mineral is optically biaxial (-) with α = 1.577(2), β = 1.620(2) and γ = 1.631(2) together with a 2Vcalc value of 52.4°. Electron microprobe analyses determined an empirical formula (based on 2S) of (Cu3.44Ni0.76Zn0.59Co0.18Fe0.01)Σ4.98S2O7.95(OH)6.05·6H2O. Based on single crystal X-ray diffraction data, the structure is monoclinic with space group P21/c and unit cell parameters a = 5.6095(8), b = 6.1259(7), c = 23.758(3) Å, β = 95.288(4)°, V = 812.92(17) Å3 and Z = 2. Single-crystal structural determination also gives an R1 value of 0.0303. The seven most intense peaks in the powder X-ray diffraction pattern [d in Å (I/I0) hkl] were found to be 11.830 (100) 002, 5.912 (64) 004, 4.845 (55) 013, 3.920 (45) 006, 2.953 (33) 008, 2.668 (57) 202 and 2.571 (36) 123, with unit cell parameters of a = 5.614(5), b = 6.108(8), c = 23.758(18) Å, β = 95.62(7)° and V = 810.8(14) Å3.
{"title":"Asagiite, NiCu<sub>4</sub>(SO<sub>4</sub>)<sub>2</sub>(OH)<sub>6</sub>·6H<sub>2</sub>O, a new member of the ktenasite group from the Nakauri mine, Shinshiro City, Aichi Prefecture, Japan","authors":"Daisuke NISHIO-HAMANE, Takeshi YAJIMA, Norimasa SHIMOBAYASHI, Masayuki OHNISHI, Takefumi NIWA","doi":"10.2465/jmps.230711","DOIUrl":"https://doi.org/10.2465/jmps.230711","url":null,"abstract":"Asagiite, a newly-discovered mineral having the ideal formula NiCu4(SO4)2(OH)6·6H2O, is a member of the ktenasite group, representing a Ni analogue. It occurs as a secondary mineral on smithsonite aggregates that overlie fractures in a serpentinite found in the Nakauri mine within Aichi Prefecture, Japan. Asagiite exhibits a unique pale blue-green coloration and so is named after the traditional Japanese color “asagi-iro.” Asagiite occurs as thin plate-like crystals with perfect cleavage along {001} planes. The crystal size of this mineral is typically 0.1 to 0.2 mm, although in rare cases crystals may range up to 0.5 mm in length. These crystals are vitreous, transparent and non-fluorescent and have also been shown to be brittle with a Mohs hardness of 2½. The measured and calculated densities of asagiite are 2.90(3) and 2.92 g·cm-3, respectively. This mineral is optically biaxial (-) with α = 1.577(2), β = 1.620(2) and γ = 1.631(2) together with a 2Vcalc value of 52.4°. Electron microprobe analyses determined an empirical formula (based on 2S) of (Cu3.44Ni0.76Zn0.59Co0.18Fe0.01)Σ4.98S2O7.95(OH)6.05·6H2O. Based on single crystal X-ray diffraction data, the structure is monoclinic with space group P21/c and unit cell parameters a = 5.6095(8), b = 6.1259(7), c = 23.758(3) Å, β = 95.288(4)°, V = 812.92(17) Å3 and Z = 2. Single-crystal structural determination also gives an R1 value of 0.0303. The seven most intense peaks in the powder X-ray diffraction pattern [d in Å (I/I0) hkl] were found to be 11.830 (100) 002, 5.912 (64) 004, 4.845 (55) 013, 3.920 (45) 006, 2.953 (33) 008, 2.668 (57) 202 and 2.571 (36) 123, with unit cell parameters of a = 5.614(5), b = 6.108(8), c = 23.758(18) Å, β = 95.62(7)° and V = 810.8(14) Å3.","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135158308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Tsukada, Purevdulam Sukhbaatar, M. Owada, T. Shimura, M. Yuhara, A. Kamei, Yusuke Shimura, Onon Gantumur
{"title":"Tectonic division of the Southwestern terrane at the western Sør Rondane Mountains, Dronning Maud Land, East Antarctica, from a viewpoint of zircon U–Pb ages","authors":"K. Tsukada, Purevdulam Sukhbaatar, M. Owada, T. Shimura, M. Yuhara, A. Kamei, Yusuke Shimura, Onon Gantumur","doi":"10.2465/jmps.221203","DOIUrl":"https://doi.org/10.2465/jmps.221203","url":null,"abstract":"","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68833244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The intensity tensor for Fe2+ doublets at the M2 sites and electric field gradient tensor for Fe2+ at the M2 sites in two enstatites (En) with the orthorhombic system were determined by single crystal Mössbauer spectroscopy to examine the ferrosilite (Fs) component dependence of the intensity tensor of enstatite. The components of the intensity tensor for Fe2+ doublets at the M2 sites in the En65.5Fs31.7Wo2.7-enstatite and En90.7Fs8.7Wo0.6-enstatite are IXX = 0.577(6), IYY = 0.454(6), and IZZ = 0.470(12), and 0.616(2), 0.458(4), and 0.426(6), respectively. Thus, those three components have a weak dependence on the contents of Fs component. The components, IXY, IYZ, and IXZ, of the intensity tensor due to Mössbauer nuclei that occupy general positions in the space group Pbca pyroxene structure are derived as IXY = IYZ = IXZ = 0 by the symmetric summation of equivalent Mössbauer nuclei in the structural site. Three components, IXX, IYY, and IZZ, were determined by applying constraint of IXY = IYZ = IXZ = 0. The intensity tensors by Mössbauer nuclei at general positions obtained without any constraints (IXY ≠ IYZ ≠ IXZ ≠ 0) are consistent with those derived by applying the symmetrical constraint (IXY = IYZ = IXZ = 0). This indicates that the intensity tensor due to Mössbauer nuclei that occupy general positions can be simplified by the symmetrical constraint.
{"title":"Compositional dependence of intensity tensor and electric field gradient tensor for Fe<sup>2+</sup> at <i>M</i>2 sites of enstatites by single crystal Mössbauer spectroscopy","authors":"Keiji SHINODA, Keita ONOUE, Yasuhiro KOBAYASHI","doi":"10.2465/jmps.221015","DOIUrl":"https://doi.org/10.2465/jmps.221015","url":null,"abstract":"The intensity tensor for Fe2+ doublets at the M2 sites and electric field gradient tensor for Fe2+ at the M2 sites in two enstatites (En) with the orthorhombic system were determined by single crystal Mössbauer spectroscopy to examine the ferrosilite (Fs) component dependence of the intensity tensor of enstatite. The components of the intensity tensor for Fe2+ doublets at the M2 sites in the En65.5Fs31.7Wo2.7-enstatite and En90.7Fs8.7Wo0.6-enstatite are IXX = 0.577(6), IYY = 0.454(6), and IZZ = 0.470(12), and 0.616(2), 0.458(4), and 0.426(6), respectively. Thus, those three components have a weak dependence on the contents of Fs component. The components, IXY, IYZ, and IXZ, of the intensity tensor due to Mössbauer nuclei that occupy general positions in the space group Pbca pyroxene structure are derived as IXY = IYZ = IXZ = 0 by the symmetric summation of equivalent Mössbauer nuclei in the structural site. Three components, IXX, IYY, and IZZ, were determined by applying constraint of IXY = IYZ = IXZ = 0. The intensity tensors by Mössbauer nuclei at general positions obtained without any constraints (IXY ≠ IYZ ≠ IXZ ≠ 0) are consistent with those derived by applying the symmetrical constraint (IXY = IYZ = IXZ = 0). This indicates that the intensity tensor due to Mössbauer nuclei that occupy general positions can be simplified by the symmetrical constraint.","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135843510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Albite porphyroblasts occur in schists in higher-grade zones of the Sanbagawa metamorphic belt, Japan. In this study of pelitic schists from the Nagatoro area of the belt, various microstructures in albite porphyroblasts were identified and indicate that grain size reduction of the albite porphyroblasts occurred after their formation. Schists with recognizable porphyroblasts contain fine grains of albite aligned in the matrix. In comparison, schists without recognizable albite porphyroblasts contain lenticular aggregations of albite grains in quartz-rich layers that suggest grain size reduction of the original porphyroblasts. These observations suggest that the absence of albite porphyroblasts does not necessarily indicate different pressure, temperature, or chemical conditions but can instead be explained by grain size reduction of albite porphyroblasts during deformation.
{"title":"Grain size reduction of albite porphyroblasts in pelitic schists of the Sanbagawa metamorphic belt, Kanto Mountains, Japan","authors":"Mutsuko INUI, Shuto KOJIMA, Yoshiya NAGATSUMA","doi":"10.2465/jmps.221219c","DOIUrl":"https://doi.org/10.2465/jmps.221219c","url":null,"abstract":"Albite porphyroblasts occur in schists in higher-grade zones of the Sanbagawa metamorphic belt, Japan. In this study of pelitic schists from the Nagatoro area of the belt, various microstructures in albite porphyroblasts were identified and indicate that grain size reduction of the albite porphyroblasts occurred after their formation. Schists with recognizable porphyroblasts contain fine grains of albite aligned in the matrix. In comparison, schists without recognizable albite porphyroblasts contain lenticular aggregations of albite grains in quartz-rich layers that suggest grain size reduction of the original porphyroblasts. These observations suggest that the absence of albite porphyroblasts does not necessarily indicate different pressure, temperature, or chemical conditions but can instead be explained by grain size reduction of albite porphyroblasts during deformation.","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135911470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Grantham, M. Satish-Kumar, K. Horie, Henriette UECKERMANN H
{"title":"The Kuunga Accretionary Complex of Sverdrupfjella and Gjelsvikfjella, western Dronning Maud Land, Antarctica.","authors":"G. Grantham, M. Satish-Kumar, K. Horie, Henriette UECKERMANN H","doi":"10.2465/jmps.230125","DOIUrl":"https://doi.org/10.2465/jmps.230125","url":null,"abstract":"","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68833594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Groundmass pyroxene crystals in pumice from the 1914 eruption of Sakurajima in Japan show varied combinations of crystallographic faces (i.e., ‘ tracht ’ ). To investigate whether the groundmass pyroxene tracht depends on magma decompression conditions, we performed isothermal single – step decompression experiments on hydrous Sakurajima dacite magma. The magma was held under water – saturated conditions at 920 °C, 120 MPa, and oxygen fugacity conditions no more oxidizing than one log unit above Ni – NiO equilibrium for 24 h. Then, a control experiment was immediately quenched, whereas others were decompressed to fi nal pressures of 20, 10, or 5 MPa and held for 3 h before quenching. Groundmass pyroxenes in the control experiment and that quenched at 20 MPa showed octagonal shapes, whereas those decompressed to lower pressures characteristically had hexagonal shapes. Some pyroxenes in the 20 MPa experiment were hexagonal near plagioclase crystals because plagioclase crystallization locally increased the supersaturation of pyroxene in the melt. We conclude that the tracht of groundmass pyroxenes changes from octagonal to hexagonal as the degree of e ff ective undercooling increases and thus re fl ects the decompression history of a magma during its ascent in a volcanic conduit.
{"title":"Tracht change of groundmass pyroxene crystals in decompression experiments","authors":"Shota Okumura, S. Okumura, A. Miyake","doi":"10.2465/jmps.211219","DOIUrl":"https://doi.org/10.2465/jmps.211219","url":null,"abstract":"Groundmass pyroxene crystals in pumice from the 1914 eruption of Sakurajima in Japan show varied combinations of crystallographic faces (i.e., ‘ tracht ’ ). To investigate whether the groundmass pyroxene tracht depends on magma decompression conditions, we performed isothermal single – step decompression experiments on hydrous Sakurajima dacite magma. The magma was held under water – saturated conditions at 920 °C, 120 MPa, and oxygen fugacity conditions no more oxidizing than one log unit above Ni – NiO equilibrium for 24 h. Then, a control experiment was immediately quenched, whereas others were decompressed to fi nal pressures of 20, 10, or 5 MPa and held for 3 h before quenching. Groundmass pyroxenes in the control experiment and that quenched at 20 MPa showed octagonal shapes, whereas those decompressed to lower pressures characteristically had hexagonal shapes. Some pyroxenes in the 20 MPa experiment were hexagonal near plagioclase crystals because plagioclase crystallization locally increased the supersaturation of pyroxene in the melt. We conclude that the tracht of groundmass pyroxenes changes from octagonal to hexagonal as the degree of e ff ective undercooling increases and thus re fl ects the decompression history of a magma during its ascent in a volcanic conduit.","PeriodicalId":51093,"journal":{"name":"Journal of Mineralogical and Petrological Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68832138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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