地学雑誌
Online ISSN : 1884-0884
Print ISSN : 0022-135X
ISSN-L : 0022-135X
96 巻 , 5 号
選択された号の論文の13件中1~13を表示しています
  • 小林 貞一
    1987 年 96 巻 5 号 p. 259-277
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
    The tenth chapter is dealt with the history of research in older rocks and Cambro-Ordovician of eastern North America. In last century Pre-Cambrian stratigraphy was started in Canada, while the New York System was instituted around Albany, N. Y. and later it was correlated to the European sequence. Subsequently the Cambrian and Ordovician Systems were classified in detail. Starting with the ventral anatomy of trilobites Walcott made invaluable contributions on the Cambrian geology and palaeontology, i.e. the Olenellus fauna, unique fauna the Burgess shale and so forth. His “Cambrian Fauna of China” 1913 provided a firm basis for the Cambrian of Eastern Asia.
    The relation of the Cambro-Ordovician faunas of the continent to the European ones in the northern part of the Appalachian geosyncline and their distribution in the Appalachian mountains and further westerly beyond the lower Mississipy river and also in the interior lowland are briefly outlined.
    These systems in the Cordilleran geosyncline is described in the eleventh chapeter. Stratigraphy in the western sites is followed by notes on the Alaskan faunas in the north which were allied to the Siberian ones at the beginning, but later to the Eastern Asiatic ones also. In the south it is a remarkable fact that the Mexicoan faunas are more related to the Andean ones than those of the United States, particularly in the early Ordovician age.
    The Circum-Pacific Cambro-Ordovician belt is taken up in the final chapter. The history of this belt's history started in the Sinian period. In the early Cambrian age the eastern side belonged to the Olenellian province, but the other side constitued the Redlichia province. Subsequently, however, trilobites of the two sides became closer related to each other, although the early Upper Cambrian Kushan fauna was quite isolated. Trilobites were intimate between the two sides of the Northern Pacific and also on the southern Pacific side in the early Ordovician age. The aspect of the provinciality in the middle and late Ordovician ages is still obscure, sofar as trilobites are concerned.
  • 林 唯一
    1987 年 96 巻 5 号 p. 278-293
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
    In the Miocene Morozaki Group of the Chita Peninsula, there are two types of fold generated under different stresses : left-stepping en echelon fold developed along the southwest coast of the Peninsula, and east-west-trending folds which are found in the east and northwest of this area. The former is a set of folds produced by left-lateral strike slip of the Atsumiwan Fault which is a splay fault at the end of the Median Tectonic Line, extending along the southwest coast of the Peninsula. The latter are folds related to right-lateral strike slip of the Chitawan and Isewan Faults, splay-faults of the Yoro-Isewan Fault which forms conjugate fault set with the Median Tectonic Line.
    On the basis of the commonly expressed concept that synsedimentary folding has a relation with the thickness of the deposits in the sedimentary basin. Investigation for the lateral variation in thickness of the four major sandstone beds revealed that there are three phases of faulting during the deposition of the Morozaki Group and in the following age of emergence.
    1) Right-lateral slip phase of the Chitawan Fault.
    This phase is contemporaneous with sedimentation of the Himaka, Katana and Toyohama Formations, being characterized by the development of E-W trending folds and E-W or N-S trending elastic dikes.
    2) Left-lateral slip phase of the Atsumiwan Fault.
    These faulting occurred concurrently with the deposition of the Yamami and Utsumi Formations, being related to the development of the left-stepping en echelon fold, the rightstepping en echelon sandstone-dike swarms, the Tsubuteura Olistostrom, the Hazikami Fault and the Utsumi Growth Fault.
    3) Right-lateral slip phase of the Isewan Fault.
    It is the phase of emergence following the deposition of the Utsumi Formation, and the E-W trending folds in the north of Utsumi were caused by these faulting.
    It is conclusded from the results of this investigation that the sedimentation and tectogenesis of the Morozaki Group took place under the alternating faulting of the Median Tectonic Line and Yoro-Isewan Fault Systems which are in a conjugated relation.
  • 佐藤 哲夫
    1987 年 96 巻 5 号 p. 294-308
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
    The most noticeable characteristic of the national urban system in Bangladesh is that it has been formed under the influence of international political changes. When the present territory of Bangladesh was separated from India in 1947, the area was much less urbanized with its urban population less than 4 %. Its small cities were just constituent of a partial set divided from the Calcutta-based urban system in the eastern part of British India. Even Dhaka, the present capital, was a local town whose population size was merely one tenth of Calcutta. The process in which those disconnected cities have formed the present urban system would show some essential factors to support a national urban system.
    The first stage of the process is the domination of the capital after the provincial government of the former East Pakistan was located. Though Dhaka had been a political center of muslims in the east Bengal, it was far from primate in the area at the time of the partition. The population of Dhaka grew more rapidly than that of Chittagong, the second largest city, to become the only nuclear of a political region. It is 2.5 times as large as Chittagong in 1981 and its primacy is still increasing. But thanks to Chittagong and Khulna which have international trade centers, the centralization of population is more or less lightened and hardly called extreme as rank-size distribution illustrates.
    The second stage is the development of large cities on a national scale by intensive industrial investment to selected centers. Industrialization was first set up with a view of substitution for the jute industries in Calcutta, and the labor-absorbing industries provided growth poles in the initial stage of urbanization. For example, Khulna, the third largest city at present, has developed only since jute mills were established in the 1950's. The top 4 cities (i.e. Dhaka, Chittagong, Khulna and Narayanganj) have not only commercial, transport and administrative function but also have industrial function, which distinguishes them from other local cities as well as population size.
    The third stage is the growth of local cities with the development of transportation network. The early example is the growth of Mymensing in the 1960's, but this is rather new trend in Bangladesh. Recent change of the means of transportation from vessels to automobiles has promoted the construction of all weather roads radiating from Dhaka, and the secondary local centers (e.g. Barisal, Sylhet, Rangpur) were emerging in each sector. The growth of local trade centers are, at the same time, supported by the recovery of consumer purchasing power after ten year economic difficulties caused by independence war from Pakistan in 1971. Spatial factor of the accessibility to Dhaka is now more effective than political factor of local administrative hierarchy.
    In connection with the change of the urban system, there are two more factors which seems to be important in the future. One is a regional development plan called “upazila development project”, which includes such projects as construction of paved roads and health care facilities in every upazila, or a local administrative unit. The plan will serve a test case of the influence of regional development on the national urban system in the third world.
    The other is the international relationship with India. The trade with India is not so much at present, but some manufactured goods flows into Bangladesh through western border. More active economic interchange with Calcutta would stimulate the rise of some cities in the western area.
    Bangladesh is still on her way of urbanization. The process above mentioned is rather common to most nations than Bangladesh proper, but the speed of change in the urban system is quite rapid and this would be the reflection of a character of Bangladeshi society.
  • 飯山 敏道
    1987 年 96 巻 5 号 p. 309-311
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
    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。
  • 松川 正樹, 梁 承榮, 小畠 郁生
    1987 年 96 巻 5 号 p. 312-314
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 中野 和敬
    1987 年 96 巻 5 号 p. 314-316
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 糸魚川 淳二, 津田 禾粒, 山野井 徹
    1987 年 96 巻 5 号 p. 317-318
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 平野 弘道, 浅井 明人
    1987 年 96 巻 5 号 p. 319-322
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 岡田 篤正, 粟田 泰夫, 奥村 晃史, 東郷 正美
    1987 年 96 巻 5 号 p. 322-325
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 門村 浩
    1987 年 96 巻 5 号 p. 325-327
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 小西 健二, 飯山 敏道, 吉田 鎮男, 町田 洋
    1987 年 96 巻 5 号 p. 328-332
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
    目的;教育・研究の立場から地学上重要な露頭を保存するための基礎資料を収集・整理する。方法;大学・県教育委員会・地方自治体博物館などの機関に, (1) 和達会長からの依頼状 (資料1), (2) 申請者からの依頼状, (3) アンケート回答用紙 (資料2) を数段階に分けて発送した。
    当初, 大学約100機関に2回にかけて依頼したところ, 12月中旬までに29機関からの回答を得たが項目ならびに地域に偏りがみられたため, 県教育委員会46, 博物館38及び若干の大学に追加依頼をした。その結果3月中旬までに, 県教育委員会17・博物館12・大学3の機関から回答が寄せられた。
    現時点の回答率は大学関係32%, 県教育委員会40%, 博物館32%である。ただし回答されたなかには「該当なし」や「回答不能」なども含まれている。
    結果;アンケート用紙に記された回答結果はデーターカードに転記後, 集計・表化したが, 露頭総数205件 (地域分布と共に第1図に示す) に及び, A4版42頁の資料集 (地学協会宛提出済) となった。
    まだ分野及び地域の偏りが解消されたわけでなく, 目下, これらのアンバランスをうめるべく検討中である。
    回答のあった総数205件の露頭を分野別に重要性の順位から評価 (例えばA・B・Cといった等級別に分類) する作業も進められているが, この作業には申請者以外の専門家の参加の必要を痛感している。
    因みに寄せられた回答をいくつかの異なる基準に従って分類・分析すると第1表の如くなる。1露頭で複数の項目にわたることがあるので, 露頭総数と各項目の件数の合計は必ずしも一致しない。
  • 佐藤 正
    1987 年 96 巻 5 号 p. 333-334
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 伊藤 和明
    1987 年 96 巻 5 号 p. Plate1-Plate4
    発行日: 1987/10/25
    公開日: 2009/11/12
    ジャーナル フリー
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