著者

角縁 進 永尾 隆志 長尾 敬介

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.29, no.5, pp.191-198, 2000 (Released:2008-08-30)

参考文献数

41

被引用文献数

15 16

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More than 40 monogenetic volcanoes are distributed over an area of 400 km2 in the Abu Monogenetic Volcanic Field, southwest Japan. The eruptive products consist of alkaline basalt and calc-alkaline andesite to dacite lavas and pyroclastics, which are collectively known as the Abu Monogenetic Volcano Group. We have examined the eruption history of the Abu Monogenetic Volcano Group based on 33 new K-Ar ages. Most samples were dated by normal K-Ar method, and yielded ages between 1.9 and 0.1 Ma. The ages of two very young samples were determined using an unspiked method incorporating a mass-fractionation correction procedure. This gave an averaged age of about 40 ka. K-Ar ages from the Abu Monogenetic Volcano Group are concentrated at around 1.7 Ma and 0.2 Ma, and the activity is therefore classified into early and late periods, respectively. The early activity had a duration of about 0.4 mys, during which time 0.3 km3 of alkaline basalt alone was erupted. The late activity produced 0.8 km3 of alkaline basalt and 2.1 km3 calc-alkaline andesite to dacite, and lasted about 0.8 mys. Alkaline basalt was mostly produced in the first half of the late period, with maximum eruption rate at about 0.4 Ma. This activity was followed by more voluminous calc-alkaline andesite-dacite eruptions which climaxed at 0.2 Ma. Although associated alkaline basalt activity continued in this period, eruption volumes steadily decreased. Periodic alkaline basalt activity in southwest Japan is thought to have originated from small mantle diapirs, with intermediate calc-alkaline magmas being produced by mixing between alkaline basalt and felsic crustal melts. Coincidence of alkalic and calc-alkaline magmas and the eruption history in the later period in the Abu Monogenetic Volcano Group suggest that heating induced by repeated intrusion of alkaline basalt resulted in partial melting of the lower crust, thus producing intermediate to felsic calc-alkaline magmas. These crustal melts may then have mixed with alkaline basalt and produced the relatively voluminous intermediate calc-alkaline magmas erupted in the latest stage.

著者

三河内 岳

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.51, no.1, pp.220214, 2022 (Released:2022-04-30)

参考文献数

89

被引用文献数

1

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For the past 30 years, I have performed a mineralogical study of various kinds of extraterrestrial materials focusing on evolution processes of Solar System bodies. The samples analyzed range from primitive chondritic materials returned by spacecrafts to differentiated meteorites including Martian and lunar samples. The first of these analyzed meteorites was an angrite, one of the oldest known achondrites, in collaboration with researchers at NASA's Johnson Space Center, USA. I pointed out the importance of olivine xenocrysts by studying many quenched angrites and showed that bulk compositions of quenched angrites were controlled by resorption degrees of these xenocrysts. Soon I became involved in studying Martian meteorites. In my early works, I found that some shergottite Martian meteorites experienced undercooling of magma and represented parent magma compositions by combining crystallization experimental results. I also revealed that nakhlite Martian meteorites had correlated petrography and mineralogy that could be explained by crystallization at different locations (burial depths) in a common cooling cumulate pile. The presence of remarkable shock features (e.g., darkening of olivine) in Martian meteorites is striking, and it appears that prolonged post-shock heating history largely erased the high-pressure polymorphs in many cases. My research deals with primitive solar system materials including Wild 2 cometary particles and Itokawa asteroidal particles. Studying these samples using electron beam and synchrotron radiation analyses has strengthened the interpretations of their origins. Another important tool employed is electron backscatter diffraction (EBSD) analysis. I applied this technique to identify several new minerals such as dmitryivanovite, andreyivanovite, and kushiroite in early 2000s. EBSD was also used to analyze preferred crystallographic orientation of olivine in brachinites, revealing rigorous magmatic and/or rheological activities in the parent body. At present I am analyzing Ryugu samples returned by the Hayabusa2 spacecraft as a preliminary analysis team member, which broadens our understanding of the formation and evolution processes of solid materials in the early Solar System.

著者

森 寛志

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.19, no.3, pp.153-158, 1990-01-31 (Released:2009-08-11)

参考文献数

13

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Deformation textures (i. e. fracturing, plastic deformation, recrystallization, vitrification, phase transforma-tion, and melting) in naturally and artificially shocked mineral crystals have been reported. The main part of this report is devoted to a description of the shock-induced residual effects in olivine and orthopyroxene crystals recovered from shock experiments by transmission electron microscopic observation. Deformation textures in naturally shocked olivine crystals from some meteorites were also described.

著者

桜井 欽一 加藤 昭

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.7, no.5, pp.348-350, 1965-11-30 (Released:2009-08-11)

被引用文献数

1 1

著者

宮島 宏

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.36, no.6, pp.184-186, 2007 (Released:2008-03-27)

著者

熊沢 峰夫

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.16, no.1, pp.73-81, 1983-03-30 (Released:2009-08-11)

参考文献数

3

被引用文献数

1

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A personal view on the current state of mineralogical communities is presented in order to facilitate the expansion of future possibilities.

著者

石川 晃

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.41, no.5, pp.203-210, 2012 (Released:2012-11-30)

参考文献数

53

被引用文献数

1

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Three enigmas of highly siderophile elements (HSE) in Earth's mantle, manifested by recent advances in HSE geochemistry of mantle peridotites, are reviewed in this paper. They are (1) the apparent overabundance of the HSE in the Earth's mantle compared to metal-silicate equilibrium, (2) supra-chondritic Pd/Ir and Ru/Ir ratios in primitive upper mantle (PUM) estimates, and (3) contrasting HSE patterns between massif- and xenolithic-peridotites. More studies on both natural and experiment-based data are clearly required for resolving these problems.

著者

土谷 信高 武田 朋代 足立 達朗 中野 伸彦 小山内 康人 足立 佳子

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.44, no.2, pp.69-90, 2015 (Released:2015-05-02)

参考文献数

89

被引用文献数

4 14

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Early Cretaceous igneous rocks in the Kitakami Mountains consist of volcanic rocks, dike rocks, and plutonic rocks, from older to younger. Plutonic rocks are composed mainly of adakitic granites in central part of zoned plutonic bodies surrounded by adakitic to non-adakitic granites in marginal part. These adakitic plutons is divided into E and W zones based on the ages and geochemistry. Zircon U-Pb ages were determined with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for 22 samples from 13 rock bodies including the Early Cretaceous adakitic granites in the Kitakami Mountains. Zircons from the adakitic granites of E zone give older ages (127-117 Ma) compared with those of W zone (119-113 Ma). Zircon ages of the calc-alkaline to shoshonitic rocks and dike rocks range from 128-124 Ma, which are similar to the oldest rocks of the E zone (127-125 Ma). Zircon ages become younger from the northern Hashikami pluton and marginal facies of the Tanohata pluton (127-125 Ma) to southern Takase granites (118-117 Ma), in the E zone adakitic granites. Petrochemical differences between the E zone and W zone rocks indicate that the adakitic melt of E zone rocks are considered to be derived from vapor-absent melting condition, while those of W zone rocks are from higher pressure and vapor-present condition.   Taking all these data into consideration, the Early Cretaceous magmatisms in Kitakami can be explained by the differential subduction model of the Farallon-Izanagi plates or slab rollback model accompanied with asthenospheric upwelling.

著者

清水 以知子

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.39, no.6, pp.208-219, 2010 (Released:2011-01-29)

参考文献数

81

被引用文献数

1

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The connectivity of grain-edge fluid channels in the lower crust and mantle is controlled mainly by the solid-liquid dihedral angle. To explain the change in equilibrium dihedral angle at elevated temperature and pressure, as observed in laboratory experiments, we developed two kinds of statistical thermodynamic models: a lattice-like model based on the Gibbs theory of adsorption, and a model based on the Cahn-Hilliard theory of non-uniform systems. The models perform well in explaining experimental data on dihedral angles in the forsterite-H2O system. The complicated temperature dependence of dihedral angle in the quartz-H2O system is possibly explained by the occurrence of multilayered adsorption.

著者

花室 孝広 梅田 浩司 高島 勲 根岸 義光

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.37, no.2, pp.27-38, 2008 (Released:2008-05-15)

参考文献数

53

被引用文献数

1 2

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The high temperature hot springs such as in Yunomine and Tosenji and the hydrothermal alteration zones of the Hongu area are distributed in the southern part of Kii peninsula, though Quaternary volcanoes which can be their potential heat sources are not distributed in the area. This research has aimed to understand the thermal history of the area by using several dating methods.     Thermoluminescence (TL) dating method was applied according to the distance from dykes or gushing out point of the hot springs which thought to be the center of alteration. The results show that the alteration age of Yunomine alteration zone is younger as it approaches the gushing out point of hot spring. No clear tendency was observed in other places. These results suggest that the alteration ages near Yunomine hot spring are controlled by the distance from the gushing out point. However, no clear tendency was observed at other hot springs between the alteration ages and the distance from the center of alteration when two or more activities of alteration have occurred.     The results of the TL, Fission Track (FT) and K-Ar dating show that after the high temperature hydrothermal alteration (until tens of millions of years ago), relatively low temperature alteration (from at least hundreds of thousands of to tens of thousands of years ago) occurred in Hongu and Totsukawa area.

著者

皆川 鉄雄

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.1, pp.30-33, 2013-01-30

参考文献数

20

著者

川崎 雅之 宮島 宏

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.1, pp.34-40, 2013 (Released:2013-03-02)

参考文献数

29

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Mr. Shinmatsu Ichikawa was a prominent mineralogist, although he was an ordinary citizen and not in government service. He lived from the late Meiji Period to the early Showa Period. He taught in elementary school and teacher training school despite not having a regular university education. He was self-taught in mineralogy and foreign language, and became a pioneer in the field of crystal morphology. His contributions include observations of the etched surfaces of natural minerals and of artificial etched quartz crystals and quartz spheres. He observed the etch pits, etch hillocks, growth hillocks and striations on the surfaces of several minerals found in Japan, engraved their positions, shapes and distributions on metal plates, and discussed his observations.   He built the Ichikawa Mineral Laboratory in his house in 1918 to store his collection of minerals, rocks and fossils (more than 7000 specimens in all). His collection includes big quartz crystals twinned after Japan law from the Otome mine, twisted quartz from the Naegi region, amethyst crystals from Mt. Ametsuka and the Yusenji mine, natural etched minerals from various parts of Japan, and many minerals from the North America. The Laboratory is a historic cultural site in his hometown. Its preservation and enlightenment activities are cooperatively carried out by the local government and a neighborhood self-governing body.

著者

平野 伸夫 竹之下 愛 土屋 範芳

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.5, pp.198-207, 2009 (Released:2009-11-26)

参考文献数

28

被引用文献数

2 2

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Carbonate hot spring is a natural chemical reaction field for understanding CO2 geological sequestration as a natural analogue. Natural analogue studies are particularly important to understand the kinetics of mineral precipitation which has potential difficulties in experimental investigations. Carbonate sinter is frequently formed in and around carbonate hot spring, which can be suitable to elucidate mechanisms of carbonate precipitation associated with flushing CO2.   Oku-Okuhachikuro hot spring, located in Kosaka town, Akita Prefecture, NE Japan, is an artificial hot spring after drilling of exploration for the Kuroko-deposits, and it is still active where carbonate sinter has still been forming continuously for more than thirty years after drilling. The temperature of spring water is 44 °C and water pH is 6.2, with discharge rate of 0.08 m3/min. The average chemical compositions of sinter correspond about 80 wt% CaCO3, and 4 wt% Fe2O3, associated with minor (<1 wt% each) SiO2, MnO, MgO, Na2O and K2O. Carbonate sinter is mainly composed of aragonite with a small amount of calcite; an intimate occurrence of these two forms of CaCO3 is the most characteristic feature of this locality. However, mineral assemblage, texture and structure of carbonate sinter are different in relation to the distance from the blowout point. Near the blowout point, the sinter is well solidified and shows laminar structure having both of calcite and aragonite. Thickness of Ca-rich laminar ranges from 20 to 150 μm and Fe-rich one is from 10 to 80 μm. Calcite and aragonite assemblage is mainly observed in Ca-rich layer. The Fe-rich layer, however, is composed only of aragonite. The sinter along downstream becomes porous and is monomineralic having aragonite as CaCO3. The observed relations on the special distribution of aragonite/calcite and the possible stability relations of these phases through EPMA and TG-DTA analyses suggest an importance of minor elements (Fe, etc.) in the precipitation of metastable carbonates: this possible effect of the precipitation of metastable phases should be taken into account in the consideration of geochemical processes of CO2 mineral trapping.

著者

木股 三善 西田 憲正 村上 英樹

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.23, no.2, pp.45-58, 1994-04-30 (Released:2009-08-11)

参考文献数

91

被引用文献数

1 1

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This paper reviews on crystal chemistry of plagioclases and geochemical roles of their megacrysts including native coppers and hydrocarbons, discussed in two parts.Part I. Structural classification of feldspar compositions can be allocated into four types; feldspar, paracelsian, hexacelsian and hollandite structures. Though the phase relation between the first and the second types has been open to question, recent probing of their isotropic temperature factors and bond-valence theory to the M-sites intensifies that feldspars are in the wide stability field from low to high temperatures under low pressures, and that high pressure and low pressure are the preference field for paracelsians. Though very common in north-east part of Japanese island and Izu-Bonin arcs, anorthite megacrysts have never been found in other districts in Japan and have been rare in world-wide occurrences. Native coppers, verified by chemical shift method of EPMA and X-ray microdiffraction, are found to be included by anorthite megacrysts from Japanese island arc and by labradorite ones from the continental margin of North America. These anorthites in the basaltic lavas are of approximately 1 to 3 cm size and often contain several corroded Mg-olivines scattering as single crytals less than a few mm long. The plagioclase megacrysts show no chemical zoning, but the anorthites with the Al/Si ordered state have partings developed in places whereas the labradorites are of the AUSi disordered structure indicative of high temperature type. Each role in their plagioclase structure establishes Mg, Fe, Al and Si cations as a few minor endmembers of CaFeSi3O8, CaMgSi3O8, AlAl3SiO8 and_??_Si4O8 for the solid solutions. Furthermore micro-inclusions of native zinc, copper and brass scattering in the red-clouded anorthite megacryst frozen by the supercooling environment could have an implication for a precusor to Kuroko deposits. Review (1) discusses both structural tolerance of plagioclases and their megacrysts including native coppers.

著者

笹木 圭子

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.27, no.2, pp.93-103, 1998-05-11 (Released:2009-08-11)

参考文献数

60

被引用文献数

6 6

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Pyrite dissolution at ambient temperatures is one of the important reactions in biogeochemical processes. It is related to the formation of acid mine drainage, where iron- and sulfur- oxidizing bacteria often grow actively and play an important role in pyrite weathering. In this article experimental studies on the oxidation of pyrite are reviewed, including pretreatment method to obtain the well-defined surface of pyrite particles, the mechanisms of pyrite oxidation by both bacteria and oxidizing agents (Fe(III) ions and oxygen), and suppressing factors of the reactions. Microbially mediated dissolution of pyrite in acidic environments proceeds mainly by the indirect contact mechanism of the iron-oxidizing bacteria, Thiobacillus ferrooxidans, that is, the bacteria mainly take part in the oxidation of Fe(II) ions to Fe(III) ions. Therefore, to suppress the weathering the reaction of pyrite with Fe(III) ions must be inhibited. In addition to the reduction and complexation of Fe(III) ions, masking of active sites on the pyrite surface by the preferential adsorption of other species is the most important factor. Based on the experimental studies, utilization of natural organic acids involved in botanical wastes is proposed for remediation and prevention of damage caused by acid mine drainage due to pyrite weathering.

著者

松本 〓生

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.16, no.Special, pp.99-108, 1983-03-30 (Released:2009-08-11)

参考文献数

24

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Abstract In view of the importance of multiple diffraction effects in X-ray and neutron diffractions, which may cause misunderstanding for the space group determinationss or intensity measurements, the geometry of the phenomena has been reviewed in a summarized form. As examples, the Umweganregung peaks for pyroxene and enargite observed for the φ-azimuth were indexed by operative and cooperative reflections.

著者

小原 泰彦

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.41, no.5, pp.193-202, 2012 (Released:2012-11-30)

参考文献数

61

被引用文献数

2 5

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The Godzilla Megamullion is the largest known oceanic core complex, located in the Parece Vela Basin, an extinct backarc basin in the Philippine Sea. The previous studies argued that the basin was active from 26 Ma to 12 Ma at an intermediate-spreading rate of 8.8-7.0 cm/year full-rate, although the basin shows the characteristics typical for slower spreading ridges. For example, many peridotites in the Parece Vela Basin are much less depleted than those exposed at comparable spreading rates on other mid-ocean ridge systems. The tectono-magmatic characteristics of the Parece Vela Basin were thus thought unusual and paradoxical.   However, the recent studies, based on the high-density samplings on the Godzilla Megamullion, show the evidences that the basin became slow to ultraslow environment in its terminal phase. Zircon U-Pb dating of gabbroic rocks from the Godzilla Megamullion reveals that the estimated slip rate of the Godzilla Megamullion detachment fault was ∼ 2.5 cm/y; significantly slower than the previous estimate. The morphology and geology of the termination area are similar to those observed in ultraslow-spreading ridges. Decreasing degree of partial melting of the peridotites as well as increased amount of plagioclase-bearing peridotites (showing melt stagnation in the shallow lithospheric mantle) are observed towards the termination of the Godzilla Megamullion.   Based on the recent observations at the Godzilla Megamullion, it would be argued that the terminal phase of a backarc basin development will go through an ultraslow-spreading environment, erupting alkaline basalts. There will be an overlap period of the terminal alkaline basalt magmatism and the rifting of a succeeding backarc basin.

著者

田崎 和江 朝田 隆二 渡邊 弘明 白木 康一

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.1, pp.22-33, 2006 (Released:2006-03-01)

参考文献数

27

被引用文献数

1 2

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Characterization of man-made rock-wool fibers were investigated by using optical and electron microscopic techniques and discussed how to affect on human health. The rock-wool fibers were collected from spraying on the roof. Mineralogical analyses were carried out by X-ray powder diffraction. Most fibers can exist as straight or curved fine threads with sharp points μm-nm in diameter under electron microscopy observations. The rock-wool is complex agglomerates of fibers and fumes with cement of calcite. The shape and size are significantly important factors for hazardous assessment of man-made fibers. The fibers are easily adhering to protein-rich spherical materials in 1% BSA (bovine serum albumin) and in ringer’s solution for few days aging. Spherical protein-like materials are similar to “asbestos body” with dumbbells shape. Man-made fibers have been manufactured for over 20 years, but there have been few concerns raised regarding the safety of rock-wool, were considered to be non-hazardous, because of the different durability in the lung. Present study consistently suggests that man-made fibers with fine and sharp points have similar risk as carcinogen of asbestos. The results of both patch test and adhesion materials with dumbbells shape provide clues regarding the mechanisms of tolerance in the lungs of exposed animals, and may be relevant for humans.

著者

山元 正継 西澤 達治 三森 俊亮 業田 顕行 緒方 武幸

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.46, no.3, pp.81-107, 2017 (Released:2017-10-07)

参考文献数

62

被引用文献数

3

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Two suites of xenoliths and an associated scoria-bearing pyroclastic fragment were sampled near Kampu volcano on Oga Peninsula of the northeast Japan arc. These scoria-hosted xenoliths consist of hornblende-bearing clinopyroxenite, hornblendite, and hornblende gabbro cumulates, hornblende megacrysts, and minor amounts of lower crustal pyroxene-plagioclase granulites. The minerals within the cumulates are euhedral and the interstitial glass is interconnected with the hosting scoria. The cumulates and their hornblende megacrysts have 87Sr/86Sr and 143Nd/144Nd ratios (0.70316-0.703390 and 0.512877-0.512974) similar to those of the Kampu magmas (0.702917-0.703409 and 0.512883-0.512988). However, these samples are not in isotopic equilibrium with each other or with the hosting scoria, with the latter having relatively constant Sr isotopic compositions (average of 0.703187). This is exemplified by two hornblende megacrysts with unusually high Al2O3 contents (< 17 wt%) that have different Sr isotopic ratios (0.703039 and 0.703235) and are isotopically homogenous from core to rim. This suggests that each melt that coexisted with the megacrysts was separated as a discrete batch without any isotopic mixing near the base of the lower crust. The host scoria was derived from discrete batches of magma having different isotopic compositions, but the scoria itself is isotopically homogeneous, indicating magma mixing and homogenization during the rapid ascent and transportation of these xenoliths from the lower crust to the Kampu volcano. This was most likely caused by the injection of upper-mantle-derived mafic magma into the base of the lower crust, as evidenced by micro-hornblende within the hosting volcanic glass that contains more Mg than the hornblende megacrysts.   The granulite xenoliths have mosaic textures, contain plagioclase with deformation twins, are closely inter-locked, and do not contain any hosting glass material. They have Sr and Nd isotopic compositions (0.70501-070532 and 0.51260-0.51263) that contrast with the cognate hornblende megacrysts, the cumulates, and the Kampu lavas, but are similar to less metasomatized lower-crustal amphibolites (amphibole with compositions of 0.70524 and 0.51261) from Ichinomegata maar near Kampu volcano. Rare hornblendes within these granulites record the onset of metasomatism, although the isotopic composition of these samples remained relatively unchanged until a subsequent cryptic metasomatic event that generated the wide range of isotopic and trace element compositions present within the Ichinomegata amphibolites.

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.46, no.2, pp.68-68, 2017 (Released:2017-05-13)

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日本新産鉱物情報(2015年)以降,2016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と,種名変更などがあるものや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.