地学雑誌
Online ISSN : 1884-0884
Print ISSN : 0022-135X
ISSN-L : 0022-135X
最新号
選択された号の論文の12件中1~12を表示しています
表紙
  • 2022 年 131 巻 2 号 p. Cover02_01-Cover02_02
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー

     Haüyne(藍方石,アウイン)[Na3Ca(Si3Al3)O12(SO4),立方晶系]は,鉱物学・結晶学の父ともいわれるルネ=ジュスト・アウイに因んで命名された準長石.Hauyniteとも呼ばれたこともあるが,宝石名にアウイナイトとしてその名を留める.アルカリに富んだ火山岩や特定の変成岩中に産する.同じくsodalite group(方ソーダ石族)に属するsodalite(方ソーダ石)やlazurite(ラズライト・瑠璃)の類縁鉱物で,共にラピス・ラズリの構成鉱物.多くは微細結晶の集合体として産し,透明度の良い結晶は稀産.青い鉱物として知られるが,白,灰色,黄,緑,薄紅色もある.初期の記載はイタリア・ヴェスヴィオ火山産で,この模式産地は現在も主要な産地である.写真の標本はドイツ西部,アイフェル(Eifel)火山群産のもの(画像左右の幅が約19 mm・国立科学博物館標本番号NSM-MF14763.撮影:門馬綱一).

    (説明:宮脇律郎)

特集:世界鉱物年2022─地球のつぶやき─
総説
  • 田賀井 篤平
    2022 年 131 巻 2 号 p. 133-146
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー

     The history of mineralogy can be traced back to the Greco-Roman period, from Theophrastos to Agricola. Linné, Cronstedt, and Werner established classical mineralogy. Crystallography developed with mineralogy, and classical crystallography was established by Haüy through Steno. In the 19th century, the discovery of X-rays by Röntgen and the discovery of X-ray diffraction by Laue gave birth to modern mineralogy and crystallography. A little later, electron diffraction was discovered, leading to the invention of the electron microscope. In Japan, Wada laid the foundations for mineralogy and crystallography.

  • 松原 聰
    2022 年 131 巻 2 号 p. 147-161
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー

     I here outline to the definition of a mineral, solid solutions in mineral nomenclature, rules of naming of minerals, and procedure for establishing of a new mineral by the Commission on New Minerals, Nomenclature and Classification, the International Mineralogical Association. Also discussed are the implications of new minerals and minerals found first in Japan. Detailed accounts are given of new minerals from Japan.

  • 圦本 尚義
    2022 年 131 巻 2 号 p. 163-177
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー

     Determining the elemental abundances of the Earth is one of the fundamental interests of the Earth and planetary sciences. The elemental abundances of the bulk solar system, chondrites and bulk Earth are reviewed. The elemental abundances of the bulk solar system resemble those of chondrites, with the exception of atmophile elements. CI chondrite may be most resemblant, but significant improvements in solar photosphere spectroscopy are necessary to reject other chondrites. Volatilities of elements control chemical variations among chondrites. These variations may reflect global thermal structures in the proto-solar disk. Alternatively, the variations may correspond to accretion ratios of chondrite-forming components, which are refractory inclusions, chondrules, and matrix, into the parent bodies. The elemental abundances of bulk silicate Earth can be empirically estimated without referring those of the bulk solar system and chondrites if we use chemical variations of mantle rocks. However, the chemical composition of bulk Earth remains largely uncertain because it is difficult to estimate the chemical compositions of the central core and the lower mantle without formation models of the Earth.

  • 大谷 栄治
    2022 年 131 巻 2 号 p. 179-192
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー

     Various phase transitions occur in the Earth's interior. They cause discontinuities in seismic velocity and density profiles. The 410 km and 660 km discontinuities are explained by the olivine–wadsleyite transformation and the decomposition of ringwoodite into ferropericlase and bridgmanite, respectively. The major transitions in the lower mantle are the spin transition in mantle minerals containing ferric and ferrous irons, the post-perovskite transition of bridgmanite, i.e., the transformation of bridgmanite into a post-perovskite phase with a CaIrO3 structure. The former transition may occur at the shallow lower mantle, whereas the latter transition occurs at the bottom of the lower mantle, which may correspond to the D″ layer at the core–mantle boundary. There are several important seismic velocity anomalies. These include low-velocity anomalies associated with hot rising mantle plumes and oceanic ridge areas, and high-velocity anomalies associated with cold slab subduction. Ocean water is returned into the mantle by hydrous minerals stored in the slabs. Some hydrous minerals such as the solid solution of hydrous phase δ and phase H, AlOOH-MgSiO4H2 are stable along the normal geotherm to the core–mantle boundary, and bring water into the base of the lower mantle. Another interesting region is located at the base of the lower mantle. These anomalies are called the Large Low Shear Velocity Provinces (LLSVP) and the Ultra-Low Velocity Zones (ULVZ). An LLSVP is considered to be a region with iron enrichment. This region may be caused by accumulations of the high-pressure hydrous phases. A ULVZ with very low compressional and shear velocities and high densities is observed at the core–mantle boundary. This region may contain dense iron rich melts. The Earth's core is composed of a molten outer core and a solid inner core. It consists mainly of iron–nickel alloy with small amounts of light elements, such as Si, O, S, C and H. The inner core is considered to be composed of an hcp phase. However, some enigmatic properties of the inner core, such as low shear velocity and anisotropy, may not be explained only by this phase. Some experimental and theoretical studies suggest the existence of a bcc phase at a high temperature region approaching the melting temperature. Therefore, the inner core may be composed of a bcc phase or a mixture of hcp and bcc (or B2 phase which is an ordered form of the bcc structure). Further studies are necessary to achieve a better understanding of the Earth's core.

論説
  • 土`山 明, 松野 淳也
    2022 年 131 巻 2 号 p. 193-211
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー

     Chondritic-porous interplanetary dust particles (CP IDPs) originating from comet and carbonaceous chondrites of asteroids are primitive materials in the solar system. This paper reviews our recent research by mineralogical approach on the primitive materials, which include reproduction experiments of glass with embedded metal and sulfide (GEMS) in CP IDPs, detailed three-dimensional structures of GEMS, and discoveries of ultra-porous lithology as a “fossil of ice” in primitive carbonaceous chondrites and CO2-rich fluid inclusions in calcites of an aqueously-altered carbonaceous chondrite based on multi-scale three-dimensional observations. From the results, together with recent dynamic models of solar system formation, a new united model of the formation and evolution of primitive materials in the solar system is proposed as a working hypothesis. In this model, GEMS or GEMS-like materials corresponding to matrices of carbonaceous chondrites form due to the evaporation of precursors followed by condensation and chondrules due to melting followed by solidification in the highest temperature and moderately-high temperature regions, respectively, through a single local heating event. These local events occur at different distances from the sun and the high-temperature products were aggregated into comets and parent bodies of carbonaceous chondrites with ice and organic materials.

総説
  • ─アウイから200年の鉱物学史上での位置付けと未来展望─
    赤井 純治
    2022 年 131 巻 2 号 p. 213-233
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー
    電子付録

     One of the most significant developing fields in mineralogy during the last quarter century involves interactions between microbes and minerals in the environment. A mineral evolution has been suggested. The fundamentals of biominerals, interactions between biosphere and minerals, and expanding knowledge of the biosphere are presented. Interactions between minerals and microbes are closely related to the evolution of the Earth's surface environment, and they suggest keys for solving environmental problems on the Earth. They are also related to the search for extraterrestrial life. This review sketches a brief history of mineralogy, referring to TEM methods, concerning regularity, irregularity, and interactions of minerals.

  • ─岩城島産の村上石を中心として─
    今岡 照喜, 永嶌 真理子
    2022 年 131 巻 2 号 p. 235-256
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー

     The mineralogical characteristics of metasomatic Li-minerals in Iwagi Islet, sugilite, katayamalite, murakamiite, Li-rich pectolite, zektzerite, sogdianite and taeniolite are summarized. These Li-minerals occur in metasomatic albitite, which contains 500 ppm Li. Such a high-Li albitite content is unusual amongst metasomatic rocks in Setouchi Province of SW Japan. Albitite forms small bodies that are several tens of centimeters to tens of meters in size, and are disseminated in a host granite of Late Cretaceous age. It shows conspicuous strain-induced textures. Murakamiite and Li-rich pectolite form a solid solution with Li × 100/(Li + Na) atomic ratios ranging from 44.2 to 60.1, and Na line profiles show a zoning structure in which Na decreases from core to rim. Albitite-normalized element concentrations vary systematically with the ionic radius of the element; normalized concentrations of cations with the same valence roughly form a simple convex parabolic curve when plotted against the ionic radius. This indicates that the element partitioning of murakamiite and pectolite during metasomatism to form albitite took place under the strong control of a crystal structure, quasi-equilibrated with metasomatic fluids and coexisting minerals. The δ7Li values of murakamiite and Li-rich pectolite show a wide range from −9.1 to +0.4‰ (average −2.9‰), and no obvious correlation with Li content is observed. These δ7Li values should have resulted from hydrothermal fluid–rock interactions at temperatures of 300-600°C (hydrothermal stages). The very low δ7Li values down to −9.1‰ may have originated from intra-crystalline Li isotope diffusion, or involvement of deep-seated, Li–Na-enriched subduction-zone fluids with low δ7Li values. The occurrence of porous zircon, dalyite, and mantles of zektzerite and/or sogdianite on resorbed zircon in albitite suggests that those zirconium silicate minerals are the products of metasomatic mineral replacement reactions by dissolution–reprecipitation processes associated with Na-, K-, and Li-rich hydrothermal fluids.

  • 清水 正明
    2022 年 131 巻 2 号 p. 257-274
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー

     Both the history of resource development and the progress of studies of mining and ore deposits in Japan are summarized. Researchers and engineers promoting in studies on ore deposits and resource geology are also reviewed, focusing on Professors Takeo Kato, Takeo Watanabe, Tatsuo Tatsumi, and J. Toshimichi Iiyama as well as other staffs of the Third Professorship, Department of Geology, Faculty of Science, University of Tokyo. Mineralogy, geology and geochemistry are essential for an understanding of resource geology. It is revealed that mineralogy plays an important role in studies on ore deposits and resource geology. Future directions of studies on ore deposits and resource geology are proposed.

  • 宮田 雄史
    2022 年 131 巻 2 号 p. 275-288
    発行日: 2022/04/25
    公開日: 2022/05/13
    ジャーナル フリー

     Gems must meet three requirements: be beautiful, be durable, and be rare. The concept beauty depends on personal values. It is, therefore, not something that is objective and separate from human society. Gems have relationships with society and have requirements. That is, it must be determined whether a gem is genuine or fake. Gems are essentially natural materials. They are generally minerals that are naturally occurring solids formed by geological processes. However, gems have a cultural aspect depending on how they are used. In a historical review, how these two aspects of gems have become the subject of scholarship is briefly elucidated. Currently, artificial gem materials are classified according to their growth history, and whether they are synthetic, man-made, imitations or composites. The task of defining these categories, in addition to natural gems and treated gems, is gem identification, which is based on gem variety, genesis (natural or artificial), treatments applied, (quality) origin (locality) and individual recognition. The development and current status of gemology is reviewed from the viewpoint of mineralogy.

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