出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.5, no.7, pp.361-362, 1893

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.5, no.3, pp.139-140, 1893

著者

日本地学史資料調査委員会

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.93, no.3, pp.168-181, 1984

被引用文献数

2 1

著者

早坂 一郎

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.82, no.1, pp.36-37, 1973

著者

早坂 一郎

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.55, no.7, pp.280-283, 1943

著者

早坂 一郎

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.38, no.7, pp.427-428, 1926

著者

宮下 純夫

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.98, no.3, pp.213-230, 1989

被引用文献数

5

---

Magma reservoir models beneath ocean ridges are reviewed with reference to the spreading rates and the mode of fractional crystallization. Faster spreading rates (5cm/year) cause a large and long-lived magma chamber in which a thick plutonic sequence would be succesively produced away laterally from the chamber. Basalts extruded at fastspreading ridges underwent various degrees of low pressure fractionation causing conspicious chemical zonation in the chambers. On the other hand, small and transient magma chambers may be present beneath slow-spreading ridges. Comparatively less-evolved basalts, where petrological characteristics are governed mostly by the deep-seated processes such as degree of partial melting and polybaric fractionation, could appear at slow-spreading ridges because of absence of a large crustal magma chamber.<BR>Since sheeted dikes in ophiolites intruded vertically and the foliation of mantle tectonites were approximately horizontal in original, the configuration of the magma chamber interlayered between the tectonites and sheeted dike complex, if it existed, can be infered from the structure of a cumulate-gabbro sequence. The appearance of a thick plutonic sequence in the ophiolite where the crystallization order is olivine-plagioclase-clinopyroxene-orthopyroxene suggests that it was generated at a fast-spreading ridge. In such thick plutonic sequence, the fine-scale igneous layering (=time plane) obliquely across the major lithologic boundary of the plutonic sequence may reflect the horizontal chemical zonation of the magma chamber. On the other hand, the appearance of abundant whelritic cumulates crystallized at mantle deths and suffered high temperature deformation suggests that the ophiolite was generated at a slow-spreding ridge.<BR>Spreading rates of ancient ocean ridges at which the ophiolites were generated may be roughly estimated from the considerations on geochemical variation of the basaltic rocks. The occurrence of evolved basalts interpreted by extensive low pressure fractional crystallization suggests fast spreading rates, whereas the appearance of less evolved basalts showing complicated geochemical features such as different incompatible element ratios and crossing REE pattern suggests rather slow spreading rates.<BR>The studies on ophiolites would bring significant informations not only on the dynamic process beneath present-day ocean ridges but also on the tectonic framework and the evolution of ancient spreading center.

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.25, no.2, pp.146, 1913

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.10, no.9, pp.510-511, 1898

著者

長沼 毅

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.122, no.2, pp.363-384, 2013

被引用文献数

2

---

&emsp;The deep subsurface biosphere has been regarded as an emerging topic in geo-bioscience and industry for the past few decades, and has been approached by terrestrial and seafloor drillings. Terrestrial sites have better proximity and greater relevance to the anthroposphere and technosphere, <i>i.e.</i>, human habitats and societies, than do seafloor sites. Therefore, understanding the subterranean biosphere has more direct importance to issues related to a sustainable civilization, and issues such as formation/maturation of hydrocarbon reservoirs and ore deposits, disposal of radioactive wastes and carbon dioxide, and postulated association between seismogenic and microbial activities. Microbiological studies in the terrestrial deep subsurface have been prompted to respond to such human-related issues, and microbial life in sedimentary and crystalline rocks as well as pore-filling fluids has been studied to evaluate rock stability and (im) mobilization of redox-sensitive elements/nuclides, for instance. This is in contrast to subseafloor microbiology, which focuses more on microbial interactions with hydrothermal circulation, relevant biogeochemical processes including gas hydrate formation, associated diversity of life, and modern analogs of origin-of-life.<br>&emsp;Avoiding man-induced contamination of cored samples and pumped fluids has been a microbiological issue. Technical (both instrumental and operational) measures to minimize contamination were first developed in subterranean microbiology, because of easier accesses to test sites for repetition, evaluation, improvement, etc. of attempted measures on land. Then, anti-contamination expertise was introduced into subseafloor practices, and anti-contamination protocols and facilities are now better developed by the Integrated Ocean Drilling Program (IODP) than the International Continental Scientific Drilling Program (ICDP). Newly developed techniques are also applied to measure/monitor geological and geochemical parameters that are used to characterize microbial habitats and processes occurring there.<br>&emsp;Lessons from subterranean microbiology are directly applicable to subglacial microbiology that may retrieve microbial life from sub-million-year-old ice cores, although additional measures are needed for glacier drilling. Because land and icy surfaces are common in Earth-like planets or potentially life-bearing satellites, lessons (experiences and expertise) from subterranean microbiology should be applicable to astrobiological searches for extraterrestrial life.

著者

岩田 修二

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.89, no.6, pp.319-335, 1980

被引用文献数

15 9

---

Movement types and intensity of surface processes were investigated on the slopes above the forest line of Mt. Shirouma-dake (2, 933 m. a. s. 1., 36&deg;45'N, 137&deg;45'E). The slopes studied are vegetation-free or sparsely vegetation covered ones that are mantled with rubble layers (thin layers of rock fragments).<BR>There are six types of slow mass movement operating on the rubble slopes talus creep, frost creep, needle ice creep, gelifluction, rapid solifluction, and a movement derived from snowpack creep. Rapid mass movement processes such as rockfalls, debris flows, and rolling down of stones often occur, but only a small amount of the materials is moved. Running water, supplied by rainfall and melting of snow and ground ice, carries the debris. While the amount of the materials moved by wash are not so large on the rubble slopes, the channel erosion is one of the important processes on the nivational rubble slopes that are covered by the long lasting snowpatches. The particle movement by wind and the transport in solution are probably insignificant on the study slopes.<BR>Relative vertical mass transfer in unit area that is a geomorphic work of process is estimated for a quantitative comparison of process intensity. The processes acting on the slopes are grouped as following five process sets according to their rates and types of the movements. I) Periglacial process set with low raet. II) Periglacial process set with medial rate. III) Nivational process set with low rate. IV) Nivational process set with medial rate. V) Nivational process set with high rate. The slow mass movements cover over 75 percent of the total mass transfer of the periglacial process set. The value of the slow mass movements of the nivational process set, however, is limited less than 75 percent of the total value and the remainder is mostly comprised in value of channel erosion. While the periglacial process sets occur on the periglacial rubble slopes that are put under the snow free dry conditions throughout the year, the nivational process sets occur on the nivational rubble slopes. The rate of these process sets vary according to the differences of the climatic environments, slope forms and gradients, and slope materials ; size of the surface material and thickness of the rubble layer. Among them the slope materials perform the important role. The process sets with low rate (less than 3.0&times; 10<SUP>3</SUP>m&middot; t/ Km<SUP>2</SUP>&middot;yr.) correspond with the processes occurring on the slopes which are mantled by the boulder size debris. The process sets with high rate (over 6.0 &times; 10<SUP>3</SUP>m&middot;t/ Km<SUP>2</SUP>&middot;yr.) occur both on the nivational slope with steep gradients and the nivational slopes covered by fine materials.

著者

鶴我 隹代子 小川 克郎 長尾 大道 羽佐田 葉子 藤井 直之 笠原 順三 熊澤 峰夫

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.114, no.4, pp.659-664, 2005-12-25

参考文献数

6

著者

飯山 敏道

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.96, no.5, pp.309-311, 1987

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日本学術会議地質学研究連絡委員会は, 1982年いらい国際地質学会議 (IGC) を1992年に日本で開催することについて, その学問的・社会的意義とその可能性などを検討する小委員会を設け, 審議をかさねました。その結果, IGCはその開催方式や内容をいままでのIGCの慣例に固執することなく, 日本独自の方式を開拓し, 準備を周到におこなえば, 技術的にも可能であり, 意義深いものにすることができるとの結論に達しました。そこで, 1984年モスクワのIGCにおいて, 日て本誘致を提案いたしました。このとき, 中華人民共和国も誘致を提案したため, 1985年2月に, IUGS・IGC共催のSteering Committeeは, 1992年日本開催に同意し, 1996年中国での開催を勧告いたしたした。正式には1989年のワシントンのIGCで決まることですが, 1985年4月IGC検討小委員会は発展的に解散し, 地質学関連の大学・官庁・企業から派遣された委員によって, 日本学術会議からは独立したIGC準備委員会が発足いたしたした。この委員会は1989年ワシントンで開催される第28回IGCにおいて, 日本開催が正式に決定され, IGC組織委員会が発足するまで機能し, 準備を整える役割をもっています。正式承認まえの準備会であるため, 公的な機能をもつことができませんが, 準備委員会内に設けられた総務・プログラム・巡検・会場・経理・出版の各小委員会が準備を進めておりますので, ここに, 活動状況を報告します。正式承認後開催まで3年の歳月しかありません。準備委員会は可能なかぎり準備を整えて1989年に発足するはずの組織委員会に引き継ぎたいと考えています。準備委員会の活動に御意見をお寄せくださるなど, 各位の絶大なる御協力をお願いいたします。

著者

岩崎 重三

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.43, no.7, pp.424a, 1931

著者

財城 真寿美 三上 岳彦

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.122, no.6, pp.1010-1019, 2013

被引用文献数

6

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&emsp;Climate variations in Tokyo based on reconstructed summer temperatures since the 18th century and instrumental meteorological data from the 19th century to the present are discussed. During the Little Ice Age, especially in the 18th century, remarkably cool episodes occurred in the 1730s, 1780s and 1830s. These cool conditions could be a significant reason for severe famines that occurred during the Edo period. Around the 1840s and 1850s near the end of the Edo period, it was comparatively warm which could correspond to the end of the Little Ice Age in Japan. Although there was a low-temperature period in the 1900s, a long-term warming trend could be seen especially in winter temperatures and daily minimum temperatures throughout the 20th century. While annual precipitation has been increasing during the last 30 years, relative humidity has been decreasing. This could result from a saturated vapor pressure rise due to warming and from a loss of water bodies due to urbanization. During the last century, not only warmer conditions but also wetter conditions in summer and autumn and drier conditions in winter and spring were documented by analyzing hythergraphs.

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.16, no.4, pp.278-279, 1904

著者

斉藤 成也

出版者

学術雑誌目次速報データベース由来

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.111, no.6, pp.832-839, 2002-12-25

参考文献数

12

被引用文献数

1 1

著者

増田 富士雄 佐藤 智之 伊藤 有加 櫻井 皆生

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.122, no.5, pp.892-904, 2013

被引用文献数

2

---

&emsp;We propose Shazam stratigraphy as a new analytical method based on facies analysis and sequence stratigraphy. This method is applied to a recently developed borehole database and subsurface geology in the Osaka Plain. Using the method, the shapes of lithofacies boundaries in subsurface sections are optimized for sedimentary faces and changes. The optimized boundary allows interpretation of seismic sections. The result is better recognition and reconstruction of depositional systems, geomorphological evolution, and tectonics. Irregular sequence boundaries, flat transgressive ravinement surfaces, and sawtooth downlap surfaces of the prograding depositional system are key boundaries for this method.

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.118, no.2, pp.Cover02_1-Cover02_2, 2009

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&emsp;ゾルンホーフェンは南ドイツのミュンヘンとニュールンベルグの中間に位置する小さな町で,その名を世界的に有名にしているのは,中生代ジュラ紀後期(約1億5000万年前)の石灰岩とそこから産出する化石である.この石灰岩は,表紙写真のように板状で緻密なためにローマ時代から壁や床などの建築材料として使用され,また1793年からはリトグラフ用の石版石としても使用されてきた.大規模な採石がされるようになると,保存のよい化石が多数発見されるようになった.そのなかでも最も有名なのは始祖鳥化石で,現在までに10標本がゾルンホーフェンから発見されている.<br>&emsp;ゾルンホーフェンの駅前には2008年に改築された化石展示を中心とした博物館(B&uuml;rgermeister-M&uuml;ller-Museum)があり,40km西方のロマンチック街道沿いの中世都市ノルトリンゲンにはリースクレーター博物館がある.南ドイツに行く機会があればぜひ訪れてほしい地質系博物館である.<br>(写真・文:白尾元理)

著者

宇根 寛 青山 雅史 小山 拓志 長谷川 智則

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.124, no.2, pp.287-296, 2015

被引用文献数

6

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&emsp;The 2011 off the Pacific coast of Tohoku Earthquake brought severe damage caused by wide-ranging soil liquefaction across the Tohoku and Kanto districts. In Abiko City, Chiba Prefecture, heavy liquefaction damage occurred in a small area, which was not accurately predicted by the existing liquefaction hazard map. The authors consider the reason to be land history, such as landform development and artificial landfill, which was not taken into account in the assessment of liquefaction risk. Accordingly, Abiko City has revised the hazard map to take account of micro-landform classifications using land condition maps, old edition maps, and aerial photographs with the assistance of the Geospatial Information Authority's support team.