地学雑誌
Online ISSN : 1884-0884
Print ISSN : 0022-135X
ISSN-L : 0022-135X
84 巻 , 4 号
選択された号の論文の6件中1~6を表示しています
  • 高野 史男, 杉村 暢二, 高阪 宏行
    1975 年 84 巻 4 号 p. 193-203
    発行日: 1975/08/25
    公開日: 2009/11/12
    ジャーナル フリー
    In Okazaki city, some blocks of city center were occupied by public offices. As these offices are the obstacle to the extension of shopping district with the city center, they have been removed to suburbs and their old sites have been redeveloped since 1970. This redevelopment is fairly large scale for a local city and the newly constructed center has multiple functions such as department stores, parking buildings, high-class speciality stores and hotels.
    In this paper, we consider the influence of redevelopment of the city center on the urban system in terms of the following three levels.
    (1) The influence on surrounding cities.
    Okazaki city is located in Nishimikawa region within Nagoya metropolitan area. The redevelopment of city center in Okazaki, therefore, have the influence not only on surrounding cities but also on Nagoya city. In analyzing the changing patterns of trade areas in Nishimikawa region before and after the period of the redevelopment, three types of areas can be recognized; (i) the areas in which the dependence-ratio on Okazaki increases and that on Nagoya decreases, (ii) the areas in which the dependence-ratios on both Okazaki and Nagoya increase, (iii) the areas in which the dependence-ratio on Okazaki decreases and those on surrounding cities or Nagoya increase. As the types of (i) and (ii) are observed in most of the areas, we come to the conclusion that the redevelopment of city center in Okazaki has led to enlarge and strengthen Okazaki trade area.
    (2) The influence on shopping streets in Okazaki city.
    Okazaki city are divided into four areas; central area in which the redevelopment has been proceeding, transitional area which is surrounding the central area in the buildup area of the city, fringe area I where population is growing, and fringe area II which is hilly region. By comparing the change of sales of shops within each area, before and after redevelopment period, we can recognize that the growth of sales in central area is over 150%. While there is little growth in the fringe areas and the decrease of growth rate in the transitional area.
    (3) The influence on the management of stores in the city.
    To sum up the conclusion of enquete method about its influence, the redevelopment lead to “the rise of pay to employees” and “the opportunity to the rationalization of store management” in central area. In transitional area, it resulted in “a diminution of customers and profits”, which means the largest damage among the three. The fringe area have little influence on the management.
    As mentioned above, the redevelopment of city center in Okazaki gave rise to various influence on the urban system. At the stage of the planning on redevelopment it may be necessary to investigate such influence beforehand.
  • 相馬 清二
    1975 年 84 巻 4 号 p. 204-217
    発行日: 1975/08/25
    公開日: 2009/11/12
    ジャーナル フリー
    A violent fire-tornado has broken out at the former site of the Army Clothing Depot in combustion caused by the destructions of the Great Kanto Earthquake at 3.30 p.m. September 1, 1923. By this fire-tornado, about 40 thousand people have been burned to death in a moment. An interpretation that the fire-tornado has been caused by passage of a cold front has generally dominated academic circles in this field up to date. According to the detailed reexaminations, this interpretation included many inconsistencies. We could obtain recently the various data with respect to the fire-tornado which occurred in the last several years. From these data, it became clear that the fire-tornadoes often have occurred near a combustion area.
    An example which was the most similar with the fire-tornado at the former site of the Army Clothing Depot was found out in the combustion of Wakayama City by an air raid on July 9, 1945. 748 persons have been burned to death by the fire-tornado in this city.
    Finally, our study leads to the conclusion that the fire-tornado at the former site of the Army Clothing Depot was caused by the widespread great fire following the Great Kanto Earthquake. There was a cold front in northwestern direction of Tokyo, but it did not play the leading role for formation of the fire-tornado.
  • 番場 猛夫
    1975 年 84 巻 4 号 p. 218-229
    発行日: 1975/08/25
    公開日: 2009/11/12
    ジャーナル フリー
    Turkey is well known for its chromite resources. Especially, the Guleman mine, southeastern Anatolia, is the most abundant in chromite reserve of this country. The mode of occurrence of the chromite deposits of this mine is briefly described based on the author's observation. Then the ultrabasic rocks and the associated chromite ores from the Andizlik-Zimparalik area, southwestern Anatolia, being studied by MTA Institute of Turkey are introduced. Comparison between chromite deposits of Turkey and those of Hokkaido, Japan is made and it is clarified that these are quite common to each other from the view point of ore genesis.
    Harzburgite or serpentinite, host rock of the chromite deposits in Turkey, generally occurs along the thrust formed during late Tertiary period. Chromite deposits enclosed in the harzburgite mass are classified into three kinds of ore : i.e. the disseminated ore partially including the stratiform ore, nodular ore and compact dense ore. The disseminated chromite ore is considered as a variety of harzburgite characterized by the presence of scattering fine-grained chromite, whereas, the mode of occurrence of the compact dense ore is different from that of the disseminated one. The dense ore shows podiform controlled by the joint directions of the host rock accompanying by the preceding disseminated ore.
    Chemical analysis for the individual chromite from the Andizlik-Zimparalik area was carried out by ENGIN (1972) and it was clarified that the chromite from the dense ore is rather rich in chromium compared with the chromite from the disseminated ore. Furthermore, he pointed out that the gangue minerals associated with the dense chromite ore are generally serpentine minerals or chlorite though forsterite is main gangue mineral of the disseminated ore.
    The above-mentioned features are one of the characteristics of the Alpine type chromite deposits, and these facts have been well known not only in Turkey but in Japan also. Following is a model interpreting the origin of the Alpine type chromite deposits.
    Harzburgite enclosing some chromite deposits is believed to be derived from the upper mantle material. Partial melting of upper mantle material rose through the crust in mush-state under the influence of the stress field of the Alpine orogeny. During this process, stratiform chromite occurs as the result of cumulus and most of chromite and olivine crystals may have been crushed or ground.
    Subsequently, gabbro, diorite, diabase, albitite or trondhjemite dykes derived from basaltic magma intrude. They are conformable with the joint directions and are particularly numerous in the marginal areas of the harzburgite.
    Hydrothermal solutions derived from the preceding dyke rocks in the deuteric stage may have formed the alteration of harzburgite and yielded the serpentinite. In addition, the hydrothermal solutions ascending along the fractures represented by the joint system may have changed the disseminated chromite ore to the compact dense ore occasionally including the nodular chromite. Hydrothermal minerals such as kämmererte or uvarovite are generally observed in the newly formed compact ore.
    Serpentinization resulted in average expansion of about 20% of the original volume. This expansion may have provided some of the impetus for renewed tectonic uplift to the present loci.
    During the uplift process of the serpentinite, above-mentioned chromite ore bodies may have changed their original shape and the Alpine type chromite ore bodies showing various irregular shape are formed.
  • 阪口 豊
    1975 年 84 巻 4 号 p. 230-243
    発行日: 1975/08/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 矢沢 大二
    1975 年 84 巻 4 号 p. 244-246
    発行日: 1975/08/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 岩生 周一
    1975 年 84 巻 4 号 p. Plate1-Plate2
    発行日: 1975/08/25
    公開日: 2009/11/12
    ジャーナル フリー
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