著者

藤井昭二

出版者

東京地学協会

雑誌

地学雑誌

巻号頁・発行日

vol.113, no.3, 2004

著者

竹村 利夫 藤井 昭二

出版者

Japan Association for Quaternary Research

雑誌

第四紀研究 (ISSN:04182642)

巻号頁・発行日

vol.22, no.4, pp.297-312, 1984-02-29 (Released:2009-08-21)

参考文献数

38

被引用文献数

12 10

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There are many active faults in central Japan. Several active faults distributed in the northern part of the Hida mountains are described in detail in this paper.The Atotsugawa, Mozumi and Ushikubi faults, 40-80km in length, are NE-ENE in trend and displaced to the right side. The amounts of horizontal displacement as revealed in the offsets of the streams crossing the fault lines are about 1-3km, and the amounts of vertical displacement are 100-300m with the northwest side upthrown.The Kazura fault, 30km long, is NNW in trend and displaced to the left side. The amount of horizontal displacement is 1km as recognized from the stream offset, and the amount of vertical displacement is 100-200m with the west side upthrown.The Atotsugawa fault has displaced the Pleistocene terraces and lake deposits (20, 000- 40, 000y.B.P.) as much as 50-60m vertically at the outcrops of the Magawa River area located up the Jyoganjigawa River. Also the Holocene terraces (about 500y.B.P.) have been displaced 1-4m vertically. The average vertical displacement rate of the Atotsugawa fault is 1-4m/1000y., and the average lateral displacement rate is 1-5.7m/1000y. as judged from the pitch θ of striation on the fault planes.Several outcrops are found along the Mozumi, Ushikubi and Kazura faults. Late Pleistocene and Holocene terraces have been cut and displaced by faults. The average rate of displacement was 0.4-1.5m/1000y. in vertical displacement. The lateral component of displacements are usually larger than or nearly the same as the vertical components.These faults can be ranked as A class or the upper half of B class in degree of activities.

著者

藤井 昭二

出版者

公益社団法人 砂防学会

雑誌

砂防学会誌 (ISSN:02868385)

巻号頁・発行日

vol.49, no.6, pp.3-8, 1997-03-15 (Released:2010-04-30)

参考文献数

25

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The Tateyama volcano is located in the central part of the Japanese Islands and situated on the northern part of Norikura volcanic zone.Volcanic activities of the Tateyama volcano in the late Quaternary, were classified into four stages. Andestic lava and pyroclastic materials were erupted during those activities. Eruption of the second stage produced so many pyroclastic materials as forming caldera. Afterwards this caldera was eroded and grew larger. A part of caldera wall was broken at Shiraiwa about twenty thousand years ago, and as the result, a lot of debris flowed over the caldera into Joganji River. The Tateyama Sabo Work is one of the largest Sabo work in Japan. Its most important work is the control of the Tombidoro which was produced by the deformation of the Tombiyama (Mt. Tombi) in the earthquake induced by the Atotsugawa fault in 1858. Deformation of the caldera wall by the earthquake may have occurred at any place in the caldera. But why did Tombi collapse occur at Tombiyama? From investigating topography of Kanayamadani and the Tombi collapse, I may conclude the cause of Tombi collapse is that Tombiyama was the terminal place of the right lateral Atotsugawa fault, and force of tension stress and depression concentrated here.

著者

藤井 昭二 藤 則雄

出版者

日本第四紀学会

雑誌

第四紀研究 (ISSN:04182642)

巻号頁・発行日

vol.21, no.3, pp.183-193, 1982

被引用文献数

1 6

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The sea-level changes since the Postglacial ages in the Hokuriku region are investigated by means of studying emerged topography, shell beds, submerged forests, sand dune and their ages.<br>As the result of investigation, the sea-level was higher than that of the present between 4, 500 and 5, 500y.B.P. along the east side of the Noto Peninsula and the Toyama Bay. While the present sea level is the highest at the Kahoku lowland on the southwestern side of the Noto Peninsula.<br>This controversial result has been solved by following considerations.<br>The coastal areas along the Toyama Bay consist of rock coasts and alluvial plains. The rock coast is uplift zone and the alluvial plain is subsidence zone generally in the order of 10^4-6 years. If uplift is severe in this region, emerged sea shells of older ages must be in a high place and sea level of younger ages must be in a low place. But the emerged sea shells clustered between 2 and 6m and higher than the present sea-level and their ages clustered in between 4, 500 and 5, 500y.B.P.<br>This evidence shows that the rate of eustatic sea-level changes is quicker than that of the uplift in the order of 10³ years.<br>Elevation of the boring site becomes the highest point of the sea-level so long as discussion was done about the boring cores. The present sea-level is the highest since the Postglacial age, because the altitude of the lowland is the same latitude of the present sea-level.

著者

藤井 昭二 Tjia D. H. Hehanussa P. Mappa Haruna

出版者

一般社団法人 日本地質学会

雑誌

日本地質学会学術大会講演要旨 (ISSN:13483935)

巻号頁・発行日

vol.1985, 1985

著者

藤井 昭二 中村 俊夫 Mappa Haruna

出版者

名古屋大学年代測定資料研究センター 天然放射性元素測定小委員会

雑誌

名古屋大学加速器質量分析計業績報告書

巻号頁・発行日

no.2, pp.70-75, 1991-03

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There are very fine marine terrace along the Bira to Pasir Putih coast southern part of south Sulawesi. These marine terrace consists of Miocene to Eocene reef coral with two notches. Position of one notch is in the one of high tide and another one is in 3-4m high above high tide with attched reef corals. ^<14>C ages of these emerged reef corals attached basement rock are dated by the Tandetron method at the Dating and Materials Research Center, Nagoya University. Result of age dating is shown is Table 1. Sea levels of 22to 40ka before present were 120 to 50m deeper than the present sea level. So uplifting rates calculate to 5.5 to 1.5mm/year. It is unresonable that two different rates estimate in same locality. Then sea level of 20 to 40ka before present must have been high geoid surface in this area.

著者

藤井 昭二 奈良 正義 畑中 盛 山口 吾一郎 堀内 一穂 奈須 紀幸 竹内 貞子 吉田 明弘 能城 修一 鈴木 三男 邑本 順亮

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.113, no.3, pp.415-420, 2004-04-25 (Released:2009-11-12)

参考文献数

14

被引用文献数

1 1

著者

大村 一夫 伊熊 俊幸 藤井 昭二 竹内 章 神嶋(竹村) 利夫 中村 俊夫 鈴木 三男 竹内 貞子

出版者

日本地質学会

雑誌

日本地質学会学術大会講演要旨

巻号頁・発行日

vol.97, 1990-09-25

被引用文献数

1

著者

藤井 昭二 野 義夫 中川登美雄

出版者

日本地質学会

雑誌

地質学論集 (ISSN:03858545)

巻号頁・発行日

no.37, pp.85-95, 1992-03-15

被引用文献数

17

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微古生物層序学と放射年代の進歩により,北陸地域の新第三系の精度の良い対比表ができた。新しい対比表を基に,最初の2時期は岩相分布図,後の7時期は古地理図をつくった。1)楡原期とそれ以前と2)岩稲期と医玉山期(20-17Ma):この2時期には火山活動が盛んで安山岩や流紋岩の火砕岩が広く分布した。3)黒瀬谷期(16.5-16Ma):海進により堆積盆が形成され"八尾一門ノ沢"動物群が支配した。4)東別所期(16-15Ma):海は拡大・深化し黒色泥岩が厚く堆積した。5)下部音川期(15-14Ma):堆積盆は再び浅くなり,暖流が流れていた。6)上部音川期(13.5-8Ma):堆積盆は浅く寒流が流れ,"音川"動物群で特徴づけられる。7)阿尾期(6.5-3.5Ma):能登半島は陸域となり,堆積盆は狭くなった。8)薮田期(3.5-1.5Ma):前期と同様寒流が流れ,石灰質砂岩が堆積した。9)大桑期(1.5-0.8Ma)浅海で寒流系の"大桑・万願寺"動物群で特徴づけられる。