著者

日本地学史編纂委員会 東京地学協会

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.110, no.3, pp.362-392, 2001-06-25 (Released:2010-04-23)

参考文献数

132

被引用文献数

2 2

著者

山本 薫

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.98, no.7, pp.911-933, 1989-12-25 (Released:2009-11-12)

参考文献数

35

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Comprehending patterns of raw material utilization for stone implements can be a key to the solution of questions concerning cultural tradition, cultural behavior, culture areas and trade in prehistoric times. The materials of stone implements reflected “knowledge of requirements (specificastion)” of the tool-makers, and this point is exemplified by stone implements of the Middle Jomon period, the Neolithic period in Japan.Patterns of raw material utilization for stone implements, at that time, were different among tool types. Evidence is presented which supports the view that Jomon people intentionally selected raw materials according to their “knowledge of tool requirements” (relating to the size and the shape of the tools). In addition, utilization of raw materials for sometypes of stone tools varied between districts. However, such differences confirmed to the intentional hypothesis.Eight types of stone implements in the Middle Jomon period, arrowheads (sekizoku), drills (ishikiri), points (sentouki, sentoujyousekki), pounding stones (tatakiishi), ground or pitted stones (suriishi, kubomiishi), querns (ishizara), roughly chipped ax-like stone tools (daseisekifu) and polished ax-like stone tools (maseisekifu), have been divided into three categories (1, 2, 3) according to the pattern of raw material utilization.Category 1 : Arrowheads, drills and points. All these are small light thin and sharp pointed tools which were made from thin flakes and hard compact silicious materials, predominantly obsidian or shale. There were two regional spheres of raw material utilization, the shale area and the obsidian area. Near the producing areas of obsidian in Chubu and Kanto districts, Jomon people tended to use this material. However, in the shale producing district, Tohoku district, Jomon people used often shale (silicious shale and hard shale).Category 2 : Pounding stones, ground or pitted stones, and querns. These stone implements are big heavy round lumpish tools which were made from round stones and primarily either andesite or sandstone. In every site in Eastern Honshu, these implements were predominantly made of one of these two rock types regardless of region. In addition, such characteristic materials used for category 1, such as obsidian and shale (silicious shale or hard shale), were rarely utilized for this category.Category 3 : Roughly chipped ax-like stone tools and polished ax-like stone tools. These are the middle weight-thickness implements for which various kinds of raw materials were used, except for obsidian and shale (silicious shale or hard shale). The typical regional patterns of raw material utilization could not be found among the sites.

著者

田島 稔

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.79, no.3, pp.139-150, 1970-06-25 (Released:2009-11-12)

参考文献数

10

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Recently, crustal movements in the Boso and Miura peninsulas have changed their mode of previous gradual sinking after the Great Kanto Earthquake to an upheaval tendency. The phenomena attracted much notice widely and increased the interest for earthquake prediction. At this opportunity, short sketch and discussion were made about the characteristics of recent crustal activities in the south Kanto district which had mainly obtained by means of geodetic repetition surveys such as levelling, tide observation, triangulation survey, distance measurement and geomagnetic survey. A picture for explaining the outline of the feature of crustal movement and a new geodetic survey planned by G.S.I. were also briefly discussed.

著者

古川 雅英

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.100, no.4, pp.552-564, 1991-08-25 (Released:2010-11-18)

参考文献数

72

被引用文献数

5 11

---

The Ryukyu Arc-Okinawa Trough system is one of several arc-backarc systems alongthe margin of the western Pacific and east Asia. Recent results of seismic refractionand reflection studies have revealed that the origin of the trough is the continental rifting, and the trough is in a state of the active rifting stage (e. g. Hirata et al., 1991; Furukawa et al., 1991). Basement rocks and sediments to appraise for the age of the trough, however, have notbeen sampled by deep sea drilling. Then the formation age of the trough was mainlyexamined by the geological studies of the Ryukyu Arc and Okinawa Trough areas andpaleomagnetic stud -ies of the Ryukyu Arc.Geological sequence of the Ryukyu Arc is generally divided into two units, thepre-Miocene basement complex and post-middle Miocene sediments (e. g. Kizaki, 1986). Thenorth and central Ryukyu Arcs represent the geological continuation of the Outer Beltof the south west Japan Arc, composed of the Mesozoic to Eocene sedimentary sequences, whereas thesouth Ryukyu Arc is characterized by high-pressure metamorphic rocks and the Eocenevolcanics and limestone. The geological and structural contrasts between the north-central andsouth Ryukyu Arcs are conspicuous before the late Miocene. These observations suggest that theformation of the Okinawa Trough have been originated since the Miocene, and the Ryukyu Archave been established since then.Paleomagnetic studies for the the Eocene to Pliocene volcanics and sedimentscollected from the Ryukyu Arc and northeast Taiwan suggest that the south Ryukyu Arc rotatedclockwise 19° with respect to the central Ryukyu Arc and Taiwan between 10 Ma and 4 Ma.Paleomagnetic studies attribute this rotation to the opening of the southern part of theOkinawa Trough during 10 and 4 Ma (Miki et al., 1990; Miki, 1991).The acoustic sequence in the trough can be divided into three units. And the eachunit are correlated to the Pliocene to early Pleistocene, middle to late Pleistocene, and late Pleistocene to Recent sediments in descending stratigraphic order. Widespreaddeformation by normal faulting is especially developed in the lowest unit which displays horst andgraben structures. The deformation would have originated at about the Plio-Pleistoceneboundary and formed the prototype of the trough (Furukawa et al., 1991). Synthesizes of the above studies have resulted in interpretativedevelopment of the trough as follows; a major phase of formation of the trough occurred during 10 and4 Ma, and reactivation of the formation of the trough occurred after 2 Ma. Recent studies fortherifting of several continental margins, however, suggest that the intra-arc rifts evolved 10times as first as major intra-continental rifts, and the life time of the rapid rifting is onlyabout 3 to 5 Myr (Yamaji and Takeshita, 1989). The middle Pleistocene reefal limestone dredged fromsome knolls in the Okinawa Trough indicate that the subsidence of the trough was about500-1, 000m after the middle Pleistocene. As a preliminary conclusion, therefore, the age ofthe trough could be estimated to be roughly 2 Ma. The present age estimation is againstrecently proposed clockwise rotation of the south Ryukyu Arc due to the opening of thetrough from 10 Ma to 4 Ma which was reported by the paleomagnetic study.

著者

三雲 健

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.99, no.1, pp.18-31, 1990-02-25 (Released:2010-11-18)

参考文献数

58

被引用文献数

3 4

---

Extensive studies on seismic activity and focal mechanism of major to moderate-size earthquakes that occurred along the eastern margin of the Japan Sea and the northern part of the Fossa Magna regions are reviewed and discussed in relation to regional tectonics. The validity of a prevailing hypothesis is also tested from various observations to see if the Northeast Honshu arc is part of the North American plate.Seismicity along the Japan Sea coastal regions extends southwestwards across the Toyama trough in one way, and also in other way to the northern Fossa Magna through a zone near the Shinano river. It has been noticed that the seismicity show temporarily successive properties similar to migration phenomena. Five major earthquakes along the Japan Sea regions have been interpreted as having thrust-type mechanisms, and the depth distribution of aftershocks of two larger events and the dip of submarine active faults suggest an eastward dipping fault plane.The maximum compressive stress derived from the focal mechanisms of more moderatesize earthquakes indicates E-W to ESE-WNW orientations, changing gradually from the northern to southwestern part of the coastal regions. In inland regions west of the northern Fossa Magna, the general trend appears oriented again in the ESE-WNW direction, which is found to be well consistent with the direction of principal compressive strains derived from geodetic triangulation surveys over the last 80 years.All the above evidence suggests that the regions under consideration may be a tectonically active, convergent zone, and might be regarded as a zone of a possible plate boundary. There is no direct evidence, however, suggesting an eastward incipient subduction of the Japan Sea lithospheric plate, from observations of submarine topography and upper crustal structure beneath the regions.Numerical calculations show that the suggested hypothesis could partly account for the observed directions of compressive stress in Northeast Honshu but is apparently inconsistent with those in Southwest Honshu. The results suggest that the Northeast Honshu arc may better be regarded as a “micro-plate” which receives strong compressive stress not only from the westward movement of the Pacific plate but also from the west side. One of possible sources of the driving stress from the west side might be an eastward movement of the “Amurian plate” which is one of micro-plates detached from the Eurasian plate. Another possible source could be bilateral extension of the central Japan Sea region or of the regions covering Northeast China and the Korean peninsula.

著者

青木 久

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.126, no.4, pp.413-424, 2017-08-20 (Released:2017-09-27)

参考文献数

31

被引用文献数

2 4

---

To investigate cliff recession processes and rates for the purpose of studying the development of horizontal shore platforms, data taken from a masonry seawall at Ashikajima located on the Choshi Peninsula coast is used. The seawall is composed of artificially cut blocks of Cretaceous sandstone, which is the same rock type as that forming shore platforms in the area. The seawall with a horizontal length of 100 m was built 90 years ago to protect reclaimed land on pre-existing shore platforms. Two sites are selected for this study: Site A without a shore platform in front of the seawall and Site B with a platform. The surfaces of sandstone blocks in the supratidal zone are depressed at both sites; Site B has a more noticeable depression. The depression depth (i.e. erosion depth) after the period of 90 years is considerably larger (more than double) at Site B than at Site A, in spite of Site A suffering direct attacks from waves, irrespective of tidal stages, while Site B experiences low-energy waves only during high tides due to the presence of the horizontal platform. Granular disintegration occurs markedly on the sandstone surface at Site B, but little occurs at Site A. This strongly suggests that salt weathering is prevalent at Site B, reducing the strength of rocks. The moisture content in sandstone blocks at Site B is lower than that at Site A, which implies that Site B is more susceptible to weathering than Site A which is always exposed to waves and tides. It would be reasonable to consider that the seawall at Site A is analogous to a cliff at the initial stage of platform development, while the seawall at Site B is similar to a cliff at its middle stage. Horizontal shore platforms start to develop due to wave action alone, but as they grow wider the importance of salt weathering increases and the combined effects of waves and weathering become crucial to platform development.

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.120, no.1, pp.Cover01_1-Cover01_3, 2011-02-25 (Released:2011-05-20)

参考文献数

4

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(表面)大陸は異なった時代につくられた造山帯のモザイクであるが,平均するとTTG組成をもつ.その大陸地殻は太平洋型造山運動でのみつくられ,現在までに地表面積の1/3を占めるまで増加している.そのほとんどは太平洋型造山運動によってつくられた.大陸の衝突による造山運動は既存の造山帯を変形再結晶させるだけで増加させることはない.大陸の造山帯のモザイクは,大陸の歴史を直接反映し,大陸地殻の形成プロセスを記録している. (裏面)第1大陸と第2大陸はTTGで構成されるが,第3大陸はアノーソサイト組成である(Kawai et al., 2009).第2大陸の分布はアジア大陸の下で最大のサイズに発達している.それは遷移層最下部(520-660km)だけでなく,下部マントル最上部にも漂移している.太平洋とアフリカ大陸直下の2つのスーパープルームとアジア直下の大下降流が地球内部の大局的なマントル対流である(Maruyama, 1994; Maruyama et al., 2007a, b).(丸山茂徳)

著者

早津 賢二

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.102, no.5, pp.611-613, 1993-10-25 (Released:2009-11-12)

参考文献数

10

著者

長岡 信治 古山 勝彦

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.113, no.3, pp.349-382, 2004-04-25 (Released:2009-11-12)

参考文献数

32

被引用文献数

5 9

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Many basaltic monogenetic volcanoes forming groups are distributed on Fukue Island, the largest island of the Goto Islands. The Onidake volcano group, 8×10 km across, is one of the monogenetic volcano groups in the island. It contains eleven monogenetic volcanoes, namely, Daienji, Koba, Nagate, Masuda, Shimosakiyama, Hinodake, Kamiozu, Shirodake, Sakiyamabana, Midake-Usudake, and Onidake, in chronological order. K-Ar and 14C dating results show that these volcanoes were active during 0.5-0.018 Ma. The average interval of monogenetic volcano-forming eruption is fifty thousand to thirty thousand years, while a long interval of about one hundred thousand years exists between 0.25 and 0.15 Ma. By long interval, the group is divided into older volcanoes, Daienji, Koba, Nagate, and Masuda, and younger volcanoes, Shimosakiyama, Hinodake, Kamiozu, Shirodake, Sakiyamabana, Midake-Usudake, and Onidake.At about 0.42 Ma, the activities of the older volcanoes started with Daienji volcano, which produced a lava flow in the north area. It was covered by thick lava flows of Koba volcano at about 0.38 Ma. During or shortly after the activity of Koba volcano, Nagate shield volcano with two small scoria cones became active in the northeastern area. At about 0.30 Ma, in the western area, Masuda volcano erupted to form a lava plateau and two scoria cones.After 0.15 Ma, in the central area, the intermittent activities of younger volcanoes began with lava flows from Shimosakiyama volcano, which was covered soon by Hinodake volcano composed of three lava flows and one scoria cone. Two small cinder cones with a lava flow, Shirodake and Kamiozu volcanoes, erupted on the northern part of Hinodake volcano. At about 0.03 Ma, at the southeastern end, Midake-Usudake volcano, erupted with three cindercone-forming scoria falls and five small plateau-forming lava flows covering an undated scoria cone, Sakiyamabana.At 0.018 Ma, the latest eruption of the group, Onidake volcano, commenced in the central area, the first phase of which was the Abunze lava flow originating from welded scoria falls or a mixture of lava and scoria fall into the lava ponds in craters. Simultaneously, the scoria falls generating Abunze lava flow contributed the formation of Osako scoria cone, which partially collapsed shortly afterwards, probably because Abunze lava carried the parts away. In the second phase, Onidake scoria falls covered a large area of 5×5 km, while Onidake scoria cone was formed in the proximal area. The third phase consisted of five lava flows, Ohma lava 1, 2, and 3 and Onidake lava 1 and 2, all of which erupted from two summit craters of Onidake cone and covered the northern and western foothills of the volcano.

著者

丸井 敦尚

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.123, no.2, pp.172-181, 2014-04-25 (Released:2014-05-16)

参考文献数

22

被引用文献数

2

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The Kanto Plain is the biggest and deepest groundwater basin on the Japanese Islands. The water in the basin has been used in various purposes, and the volume of use is estimated to be the greatest in the country. Consequently, severe problems have emerged in the history of water development and water environment protection. The study show two stories in the groundwater basin of the Kanto Plain, corresponding to depth. The deeper one emphasizes salt water containing natural gas, and the shallow one is characterized by the largest groundwater flow system in the country. The paper reviews the geological features of the basin. Groundwater condition, especially deep groundwater, is also reviewed to understand the next stage of activities to develop and protect the environment.

著者

藤岡 換太郎

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.97, no.1, pp.39-50, 1988-02-25 (Released:2009-11-12)

参考文献数

59

被引用文献数

1 2

---

Topographic features around Izu Oshima region were summarized with special references to the characteristics relating to subduction of the Philippine Sea plate (PHS) along the Sagami Trough. Several topographic highs having circular contours around Oshima Island may be the results of parasitic eruption of Oshima Volcano. Their trend is almost parallel to the elongation of the linearity of parasitic cones distributing onshore. Along the eastern trench slope off Oshima Island, large scale collapse structures are seen in the submarine topographic map. These are the result of the falling down mostly of pyroclastic materials (tephras) during historic ages. The Oshima Island shows eastward tilting owing to the bending resulted from the subduction of the PHS. Large scale of the collapse structures may be caused by the oversteepening of the eastern trench slope of Oshima Island and soft sediments consisting mostly of pyroclastics including a large quantity of pore water slide down along the trench slope as far as the Sagami Trough.Radial distribution both of saddles and valleys observed northeastern offshore part of the Oshima Island may be lava flows and/or dike swarms derived from the old Okata Volcano whose eruption center was estimated to exist at the northeastern extension of the Oshima Island.About 4 km south off the Oshima Island, large scale of the topographic breakes consisting of caotic highs and depressions are seen in the submarine topographic map. These may be debris flow deposits along eastern slope of Ohmurodashi which consists mostly of the Quaternary rhyolites geologically and chemically similar to those exposed on the Niijima and Kozushima Islands. These are the results of catastrophic phreatomagmatic eruption of the Ohmurodashi such as that of the Myojinsho. Mixture of pyroclastics and lavas will be found from these caotic areas.The upper steam of the Sagami trough shows notable meandering whose direction is almost parallel to that of the movement of the PHS east off Oshima Island and almost perpendicular east off Ohmurodashi. At the latter case, thrust structures may trace along the subduction zone at the landward slope of the Sagami trough. Just landward side of the thrust, curious round topographic highs can be observed. They may be mud volcanoes.Topographic features observed around Oshima Island may best be understood in term of the normal and oblique subduction of the Philippine Sea plate along the Sagami Trough.

著者

尾方 隆幸

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.120, no.5, pp.viii, 2011-10-25 (Released:2012-01-17)

参考文献数

1

著者

鵜川 元雄 藤田 英輔 熊谷 貞治

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.111, no.2, pp.277-286, 2002-04-25 (Released:2009-11-12)

参考文献数

13

被引用文献数

6 12

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Continuous seismic observations at Iwo-jima, an active volcanic island belonging to the Izu-Ogasawara island arc, have detected remote triggering of microearthquakes in and around the island. The remote triggering at Iwo-jima is a phenomenon of an abrupt increase of microearthquake activity at the time of a passage of seismic waves from a distant large earthquake. We examined seismograms of a total of 21 earthquakes with magnitude larger than 7 and within an epicenter distance of 3000 km from Iwo-jima. Remote triggering phenomena were found at four events during the period from 1980 to 1993 : the 1983 west off Tohoku earthquake, the 1984 southeast off Kyushu earthquake, the 1993 southeast off Hokkaido earthquake, and the 1993 Mariana Island earthquake. The largest epicenter distance among them was 2009 km. The initial times of triggering coincide with the theoretical arrival times of surface waves and successive occurrences of earthquakes continued for 6 to 15 min, suggesting that dynamic stress or strain caused the remote triggering phenomena at Iwo-jima. As a well-developed hydrothermal system is suggested in shallow depths beneath Iwo-jima, volcanic fluids presumably play an important role in remote triggering.

著者

三上 岳彦 大和 広明 広域METROS研究会

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.120, no.2, pp.317-324, 2011-04-25 (Released:2011-06-30)

参考文献数

10

被引用文献数

10 16

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This paper describes our newly developed high-resolution temperature observational system called Extended-METROS, which has been deployed in the Tokyo Metropolitan Area since 2006. Some climatological mean temperature charts using Extended-METROS data are analyzed in terms of urban climatology, and detailed urban heat island temperature patterns are clarified. Rainfall measurements were set up from August 2010 at 40 points in the Tokyo Metropolitan Area. The relationship between urban heat islands and local-scale heavy rainfall patterns in urban areas will also be analyzed based on our high-resolution meteorological observation system.

著者

岡田 篤正 安藤 雅孝 佃 為成

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.96, no.2, pp.81-97, 1987-04-25 (Released:2010-02-25)

参考文献数

35

被引用文献数

6 2

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Four trenches (Trenches A-D) were explored across the Yasutomi fault (a strand of the Yamasaki fault system) to date recent past faultings. Trench A was 3 m deep and 28 m long across the fault (Upper in Fig. 3 and Fig. 4), and the additional excavation was made down to 5 m deep (Fig. 5) from the western wall of trench A. The sizes of other tenches are similar to that of trench A. Since this site was being developed after this trenching for the building lot of a factory, many pieces of important geological evidence were gradually exposed with progress of the construction. This enabled us to make a further detailed geological and geomorphological study of the Yasutomi fault. The results are summarized as follows : 1) Yasutomi fault, which has been considered to be predominantly left-slip active one estimated from tectonic morphologies, was geologically confirmed that this had dislocated with predominantly lateral-slip component at least since a few tens of thousand years.2) Widely sheared zones appeared along the north side of the active trace do not accompany any tectonic features. Therefore, this straightly trending depressional zone is to be recognized as a fault-line valley. A new fault was originated along the southern rim of pre-existed weak zone probably since the late Quaternary.3) The valley-filling deposits are disturbed at the lower part of the trench but not at the upper part this suggests that the fault has not moved since the deposition of the upper horizon although small earthquakes have been reported to occur frequently around the fault. Sense and amount of vertical offset, drugged structure and other fault features vary laterally along this, as common in high angle strike-slip fault.4) The latest displacement occurred between late 7 th and 12 th Centuries, probably associated with the 868 Harima Earthquake (M=7.1). Two more faultings were also inferred from C-14 dates of disturbed and undisturbed strata within a deformed zone of the fault, although they are less reliable. The recurrence interval of earthquakes as large as the 868 event is estimated to be at least 1000 or possibly a few thousand years along this strand of the Yamasaki fault system.

著者

木下 良

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.110, no.1, pp.115-120, 2001-02-25 (Released:2009-11-12)

参考文献数

24

著者

田中 和広 石原 朋和

出版者

Tokyo Geographical Society

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.118, no.3, pp.499-510, 2009-07-07

被引用文献数

5 10

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The Nabetachiyama Tunnel 9116 m long was excavated in Tokamachi City, Niigata Prefecture and encountered the serious difficulties during excavation. In particular, a 600 m long section in the Matsudai area had experienced difficulties caused by swelling mudstone in the Tertiary Sugawa Formation. A 120 m bore hole long was excavated in the neighborhood of the section and geological and geochemical examinations of sampled cores were carried out to investigate the formation mechanism of the swelling rock mass. Mudstone distributed deeper than 50 m in the bore hole can be correlated to the tunnel troubled section geologically and geochemically. The section is assumed to be composed of mud breccia with mudstone fragments and clayey matrix, which is thought to be generated by hydro-fracturing of mudstone, showing weak strength due to large quantities of clay minerals. A gas pressure of 1.6 MPa thought to be caused by degassing of methane was measured during tunnel construction, which would increase the swelling properties. Mud breccia distributed deeper than 50 m contains a lot of Na-smectite formed in highly saline pore water ascending from deep underground. The result of slaking test showed that mud breccia filled with saline groundwater is characterized by quick slaking and swelling due to the marked contraction of Na-smectite when drying. In summary, the swelling rock mass distributed in the troubled section was formed by the weak rock strength caused by hydro-fracturing and high gaseous pressure generated by degassing. Furthermore, quick slaking caused by repeated wetting and drying was another reason for swelling during excavation.

著者

藤原 咲平

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.29, no.12, pp.769-783, 1917-12-15 (Released:2010-10-13)

著者

藤原 咲平

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.29, no.11, pp.701-712, 1917-11-15 (Released:2010-10-13)

著者

北里 洋

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.107, no.2, pp.258-273, 1998-04-25 (Released:2009-11-12)

参考文献数

87

被引用文献数

1 1 1

---

To analyze oceanic paleoenvironmental histories, paleoceanography has used various biological proxies such as characteristic species, molecular bio-markers, chemical components and others. Much of paleoceanographic information originates from skeletal remains and/or chemical compounds of marine organisms. Accordingly, we are always faced with the biological problem of so-called “vital effects”. Experimental paleontology is a research method to determine relationships between organisms and their biotic and / or abiotic environments through well-controlled culture experiments. This is one of the best ways to shed light into the “vital effect” black box.In this article, I review previous studies which have tried to solve paleontological problems through culture experiments using foraminifera. There are three different scales of experimental methods. First is a culture in a petri dish. This method is advantageous to observe the relation between individuals and environmental factors. Second is micro-and mesocosm experiments which tried to reconstruct a part of the marine ecosystem in laboratory. With this method one can examine interactions between organisms and biotic and/or abiotic factors. Third is in situ experiment in the sea using submersibles or benthic landers. These methods play the role of finding clues about, or proving the nature of, currentbiological proxies of paleoceanography. I strongly invite young scientists to work with experimental cultures for the better understanding biological proxies in paleoceanography. Several suggestions for future studies are also proposed in the text.