著者
松原 聰
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
pp.231004, (Released:2023-10-20)

日本新産鉱物情報(2021年)以降,2022年12月末までに確認された日本産新鉱物および新産鉱物,その他について紹介する.太字は少なくとも化学的,結晶学的性質が明らかにされたもので,信頼度が高い.
著者
中里 浩也 大場 孝信 板谷 徹丸
出版者
一般社団法人 日本鉱物科学会
雑誌
岩鉱 (ISSN:09149783)
巻号頁・発行日
vol.91, no.1, pp.1-10, 1996 (Released:2006-12-13)
参考文献数
14
被引用文献数
6 8

The geology and K-Ar geochronology of the Gassan volcano in Northeast Japan were carried out to establish the volcanic history.     This volcano is belonging to the Chokai volcanic zone, and composed of several volcanic edifices. On the basis of the field geology and K-Ar dating of the ejecta, the volcanic history is divided into five stages;      Stage I (0.88 Ma): the Amamoriyama was formed by dacite volcanism. The dacite lava is composed with hypersthene, augite, hornblende, biotite and quartz phenocrysts.     Stage II (0.7 Ma): The Yudonosan, which is composed of a stratovolcano and two lava domes of mainly dacite lava and pyroclastics.     Stage III: The volcanism occurred in the north of the Yudonosan. The dacite lava and pyroclastics covered on the basements in the caldera and the lower Yudonosan lava in the Ishihane river.     Stage IV (younger than 0.6 Ma): The volcanism of the major stratovolcanoes of central Gassan, the Waratahageyama and the Ubagatake, which are composed of lavas and pyroclastics. The rocks are calc-alkali andesite containing hypersthene, augite, sometimes a small amount of olivine and rarely hornblende.     Stage V: The collapse of the northwestern half of Gassan stratovolcano, caused the formation of a horseshoe-shaped caldera and dry avalanche deposits.     The rocks of the Gassan volcano are divided into two groups, dacite and andesite in their temporal as spatial distributions.
著者
越後 拓也 木股 三善
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
vol.38, no.3, pp.57-74, 2009 (Released:2009-07-23)
参考文献数
167
被引用文献数
1

Organic minerals are natural organic compounds with both well-defined chemical composition and crystallographic properties; their occurrences show traces of the high concentration of certain organic compounds in natural environments. Thus the origin and formation process of organic minerals will lead us to understand the fate and behavior of the organic molecules in the lithosphere. This review divides organic minerals into the following two groups to discuss their contribution to new developments in mineralogy: ionic organic minerals in which organic anions and various cations are held together by ionic bonds, and molecular organic minerals in which electroneutral organic molecules are bonded by weak intermolecular interactions. This review is composed of five sections. The first section is concerned with the definition of both organic minerals and the above two groups. The second deals with crystal chemistry and geochemistry of oxalate minerals, which are the most typical ionic organic ones. In this section, the role of (H2O)0 is firstly discussed since most oxalate minerals incorporate (H2O)0 into their crystal structures. Then the phase relationships among hydrous/anhydrous calcium oxalate minerals, namely their structural hierarchy are described, owing to the fact that they are the most abundant ionic organic minerals. In addition, the weak Jahn-Teller effect in humboldtine [Fe2+(C2O4)·2H2O] is mentioned. Fe2+ ion causes octahedral distortion in the organic mineral though the effect has hardly been observed in inorganic minerals. The third describes the origin and formation process of karpatite (C24H12), which is the molecular crystal of coronene and the most typical molecular organic mineral. The fourth and last sections summarize the characteristics of organic minerals and discuss their contribution to earth science, respectively.
著者
荒岡 大輔
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
vol.44, no.5, pp.259-270, 2015 (Released:2015-11-11)
参考文献数
66

Lithium, one of the ‘rare metals’ defined by Japanese government, is industrially important, and Li compounds are used for many purposes (e.g., Li-ion batteries). The major types of lithium deposits are (1) brine, (2) pegmatite, and (3) sedimentary deposits. Because of the low production costs for Li in brine deposits, they account for approximately 60% of identified worldwide Li resources and for approximately 70% of worldwide Li production. Recent increases in Li production, an expected high demand for its use in eco-friendly cars, and uneven distribution of Li-producing countries underline the importance of maintaining a stable Li supply. Therefore, more brine deposits should be exploited, and the development of other types of Li deposits should be explored.   Lithium carbonate is extracted from brine deposits in playas and salt crusts by exploiting the solubility differences of different ionic compounds. Li-rich brine deposits probably form by orographic/topographic effects and by local hydrothermal activity, because Li is a fluid-mobile element and its elution from solids into fluids is temperature dependent. Lithium-pegmatite deposits probably form by intermittent intrusions of pegmatite magma in which Li has become concentrated by the addition of Li-rich differentiates from felsic magma, because Li is a moderately incompatible element. Sedimentary-type Li deposits, which are composed of hectorite and jadarite, are still relatively undeveloped, but they are attracting a great deal of attention as possible new Li resources. In addition to these sources, methods to extract Li from seawater and to reclaim Li by urban mining of discarded products have also been examined.   Lithium isotope analysis is a powerful tool for tracing water-rock interactions and for investigating various geochemical and geological processes. Moreover, the origin of Li and the history of Li accumulation in Li deposits can often be determined from its isotopic signature.
著者
川原 治之助
出版者
一般社団法人 日本鉱物科学会
雑誌
鉱物学雜誌 (ISSN:04541146)
巻号頁・発行日
vol.13, no.2, pp.84-90, 1977-01-30 (Released:2009-08-11)
参考文献数
3
著者
鉱物科学に関する用語検討委員会
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
vol.44, no.6, pp.345-346, 2015 (Released:2016-01-09)

「直方晶系(斜方晶系)」への対応 鉱物科学に関する用語検討委員会
著者
松原 聰
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
vol.49, no.1, pp.35-37, 2020 (Released:2020-05-02)

日本新産鉱物情報(2018年)以降,2019年12月末までに確認された日本産新鉱物および新産鉱物,その他について紹介する.太字は少なくとも化学的,結晶学的性質が明らかにされたもので,信頼度が高い.
著者
岡田 敏朗 長瀬 敏郎 今井 裕之 上原 誠一郎
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
pp.170618, (Released:2017-12-07)

Sakura quartz, which shows cherry blossom-like texture on the (0001) cross-section, occurs from Obira mine in Oita prefecture, Japan. The unique texture was analyzed by using CL, EBSD, EPMA, BSE, and OPM. The texture includes numerous solid and liquid inclusions, and is composed of Brazil twin lamellae and Dauphine twin domains. The texture would be named as sakura texture after sakura-ishi (cerasite), which was a variety of cordierite. The quartz crystal with the sakura texture grew by two growth stages. At the first stage, numerous inclusions were incorporated into the milky part and the growth bands are indistinct. In contrast, growth bands were clearly observed at the second stage. The sakura texture developed at the first stage. Almost all quartz crystals from Obira mine have the sakura texture, and the texture formed on replacement process at late greisenization. The sakura texture is a characteristic feature of quartz from skarn deposit.
著者
坂野 靖行
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
pp.230516, (Released:2023-08-08)

Monazite in a granite pegmatite from Yamanoo, Sakuragawa, Ibaraki Prefecture, Japan has been examined in terms of U, Th, Pb, and rare earth element (REE) chemistry by electron microprobe analysis. This pegmatite occurs as a lenticular vein in the Kabasan granitic body. Oscillatory and sector zoning were observed by back-scattered electron images. An averaged empirical formula was (Ce0.286Nd0.180Sm0.104La0.077Y0.069Pr0.041Gd0.069Dy0.020Er0.004Th0.069U0.011Ca0.052)Σ0.982 (P0.983Si0.027)Σ1.010O4. Compositional variations suggest that the (Th + U) contents are controlled mainly by the coupled substitution (Th, U) + Ca = 2REE. Calculated U-Th-Pb chemical ages based on the assumption that the initial Pb is negligible are 61 ± 11–69 ± 10 Ma (2σ) and consistent with previously reported radiometric ages for the Kabasan granitic body.
著者
小澤 一仁 永原 裕子
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
vol.42, no.3, pp.136-155, 2013 (Released:2013-07-02)
参考文献数
145
被引用文献数
1 3

Approaches to elucidate thermal history of the earth based on information of earth materials are reviewed. Limitations of these approaches are examined, and ways for the improvement and additional approaches to better constrain the thermal history of the earth are proposed. A short note of the current thermal status of the earth is followed by examination of earth's thermal history based on geophysical modeling of mantle convection, combination of which with material information is essential to deepen our understanding. There are several proxies of earth materials for secular changes of the thermal state of the earth's interior. Those often used so far are: (1) chemical composition of magmas, from which ‘potential temperatures’ of the ambient mantle are estimated, (2) pressure and temperature conditions of crustal materials (metamorphic rocks), from which ‘metamorphic geothermal gradients’ are estimated, (3) thickness of the crust and lithosphere, from which thermal gradients of the crust and lithosphere are estimated along with the temperature estimation of the bottoms, and (4) pressure and temperature of mantle materials, from which ‘mantle geothermal gradients’ of the lithosphere are estimated. Each method has problems to be resolved for quantitative estimation of the secular variation of the earth's thermal state. The following approaches are proposed: (1) coupling thickness of oceanic crust and depletion zone of residual mantle and major element composition of volcanic rocks, (2) high-resolution analysis of thermal history of crust and mantle materials to better constrain steady-state geotherms, and (3) simultaneous estimation of ambient pressure and temperature as well as mantle potential temperature from analysis of magma intrusions in the crust. Finally, the importance of extraterrestrial materials and earth-like exoplanets to reveal thermal history of the early earth, for which direct information is not available, is remarked.
著者
宮本 正道
出版者
一般社団法人 日本鉱物科学会
雑誌
鉱物学雜誌 (ISSN:04541146)
巻号頁・発行日
vol.24, no.4, pp.259-263, 1995-10-31 (Released:2009-08-11)
参考文献数
18

The method to estimate the cooling rate of meteorites on the basis of atomic diffusion in minerals is summarized. The best-fit cooling rate and burial depth are obtained by fitting a profile calculated by solving the diffusion equation to the observed chemical gradient and the width of lamellae measured by electron microprobe. The thickness of a eucntic crust of the HED parent body was estimated to be about 10 km from augite exsolution in pyroxene. A rapid cooling of a few hundreds °C/yr for pallasite was obtained on the basis of chemical zoning in olivine. Some problems with estimation of the cooling rate are also reviewed.
著者
纐纈 佑衣
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
pp.230110a, (Released:2023-04-13)

Spectroscopy has been widely used in geology since the 1990s because it is non-destructive and easy to analyze. Raman spectroscopy has generally been used to identify mineral phases in geology, but recent studies have proposed new methods to quantitatively estimate the metamorphic pressure (quartz Raman barometry) and peak temperature (Raman carbonaceous material geothermometry). Studies using infrared spectroscopy are also underway to advance our understanding of hydration processes in subduction zones and mantle through the analysis of water in rocks. In addition to the development of new methods using spectroscopy, new tools are also being developed to analyze huge amounts of data through iterative processing, which will enable the extraction of more informative and quantitative results in a shorter time. This paper introduces examples of spectroscopy applications in geology and examines future developments.
著者
松本 啓作 平島 崇男
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
vol.35, no.2, pp.97-108, 2006 (Released:2006-04-10)
参考文献数
6
被引用文献数
4 4

We propose a new modal analysis method using a scanning electron probe microanalyzer with an energy dispersive X-ray analytical system. The procedure is based on the multipoint analysis software of EDAX® Inc. The analysis points are selected as equal interval grids in the secondary electron image (SEI), which covers 3.2 × 2.45 mm2 area as the maximum. The mineral identification of each X-ray spectrum can be done by the combination of the assemblage and content of mineral forming elements. This method can identify most of rock-forming minerals easily, what is an advantage comparing with the conventional modal analysis method under the optical microscope. To obtain the reliable modal data, we can adjust grid intervals depending on the grain size of rock forming minerals and the numbers of the beam acquisition areas depending on the degree of heterogeneity of samples. This technique is available for the rock sample with average grain size between 0.2 and 2.0 mm by the restriction of the minimum enlargement size of the SEI. The new method gives the concordant modal data to those obtained by the conventional point-counting method by several beam acquisition areas for homogeneous samples and by a few tens beam acquisition areas for heterogeneous samples.
著者
西川 治
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
pp.230127, (Released:2023-04-08)

秋田大学大学院国際資源学研究科附属鉱業博物館 ─岩鉱分野の展示の見どころ─
著者
松原 聰
出版者
一般社団法人 日本鉱物科学会
雑誌
岩石鉱物科学 (ISSN:1345630X)
巻号頁・発行日
pp.220217, (Released:2022-03-08)

日本新産鉱物情報(2020年)以降,2021年12月末までに確認された日本産新鉱物および新産鉱物,その他について紹介する.太字は少なくとも化学的,結晶学的性質が明らかにされたもので,信頼度が高い.