地学雑誌
Online ISSN : 1884-0884
Print ISSN : 0022-135X
ISSN-L : 0022-135X
89 巻 , 3 号
選択された号の論文の8件中1~8を表示しています
  • 矢ヶ崎 典隆
    1980 年 89 巻 3 号 p. 149-166
    発行日: 1980/06/25
    公開日: 2010/10/13
    ジャーナル フリー
    Japanese immigrant agriculturists on the west coast of the United States in the pre-World War II period enjoyed a highly competitive position with their small but labor intensive operations even under social conditions that often discouraged their activities. One of the biggest factors in their competitive success in agriculture was their organizational effectiveness. Ethnic solidarity was maintained by first generation immigrants of most ethnic backgrounds both in fraternal and economic activities and they tended to cluster geographically and by occupation. But the Japanese agriculturists developed especially tight and efficient organizations to meet special needs and to protect themselves in this new and unaccustomed environment.
    The present paper describes and analyzes the development of Japanese floriculture in the San Francisco Bay Area from its beginnings in the late nineteenth century to the World War II relocation of the Japanese, with special emphasis on grower organizations as a key factor in their success.
    The early pioneering efforts and success of the immigrants, who were mostly of rural background, invited the participation of other Japanese in commercial flower production. The mild climatic conditions of the Bay Area, especially the absense of temperature extremes, were favorable for cut flower production, and the rapidly growing population created an increasing demand. Although two other ethnic groups, Italians and Chinese, were already in the business when the Japanese first started to grow flowers commercially, the industry itself was not fully organized. The Japanese thus moved into a niche that was waiting to be filled.
    In the early period the Japanese flower growers were mainly located in the East Bay region, producing carnations, roses and chrysanthemums in greenhouses. Marketing of flowers was undertaken on an individual basis, peddling them from wicker or bamboo baskets carried on the back or by opening flower stands on busy streets, which was generally inefficient and time consuming. As the number of growers increased and production expanded, intense competition developed among them. Gradually they became aware of a need for their own trade organization and marketing facility.
  • 大森 博雄
    1980 年 89 巻 3 号 p. 167-178
    発行日: 1980/06/25
    公開日: 2010/12/22
    ジャーナル フリー
    The sand dunes in Australian continent have beeen classified into two kinds of shapes and origins. The moving dunes, however, are separated into two types of moving patterns and activities.
    The first type is called“the regional moving dune”. It means a group of dunes which are active only on their crests with weak activity and are spreaded over wide area. Its distribution is limited in the arid zone of the continent. The movement of sand on their crests is presumed not to mean the result of climatic change but to show the equilibrium condition with the present climate of the area. It is not clear, however, whether the active parts on their crests have been changed in magnitude.
    The second one is “the local moving dune”which means that one or some dunes are remarkably active in spite that most dunes surrounding them are tightly fixed. Their characteristics are different from those of the regional moving dunes. Namely, the local moving one is active not only on the crest but also on the side and foot, the groundswells of sand are formed on it and buried woods are scattered on its leeward. These local moving dunes which are occurring mainly both along the marginal belt of the arid zone and in the semi-arid one are observed only in the artificial areas such as pastoral land and agricultural one. It is presumed that the movement of sand on them has started recently, as some of them began their action after the trees on them had been fallen down, though almost all of them were fixed once by being covered with vegetation. It is not clesr, however, whether the movement of dunes has started or not before the artificial action was done in the areas.
    It is though that the climate has been so exceeding dry that the dunes which were fixed have had potential mobility in and around the semi-arid zone at least in the southern part of the continent and it is inferred that this potential mobility of some dunes has been actualized by some artificial actions from the facts as follows:
    The local moving dunes are distributed mainly along the critical boundary of climatic zones such as the marginal belt of the arid zone and the semi-arid one where it is extremely sensitive to both the effect of climatic change and its reflection on landform and vegetation. They are so remarkably active in movement that they would unlikely be fixed under the present natural condition and there are some dunes which are ready to be started moving among the tightly fixed ones in the area where there has been little action of man.
    Further, there needs more researches on the basis of the climatological and geomorphological data of the wider region including New Zealand to make clear which this climatic change toward dryness means the expansion of the interior arid zone or the desiccation of the westerly flowing from west to east along the sourthern part of the continent.
  • 徳山 英一
    1980 年 89 巻 3 号 p. 179-197
    発行日: 1980/06/25
    公開日: 2010/10/13
    ジャーナル フリー
    Cretaceous volcanic rocks have been collected from seamounts, linear islands chains, oceanic plateaus such as Manihiki Plateau and Ontong Java Plateau, and various types of deep-seated intrusions which are distributed in the cent ral Pacific Ocean. They may be classified into two types; 1) ocean island tholeiites, alkalic basalts and their differenciated rocks such as hawaiite, mugearite and trachyte, and potassic nephelinites; 2) ocean plateau tholeiites. Volcanic rocks of the first named type are found at seamounts, linear islands chains, and small sized deep-seated intrusions emplaced during the late Cretaceous (Campanian to Coniacian). While rocks of the latter type are found at oceanic plateaus and large sized deep-seated intrusions empl aced during the early Cretaceous (Barremian to Hauterivian and/or Valanginian). The age span of the ocean plateau tholeiite might continue to some extent until middle Cretaceous. Each volcanic suite is characterized by approximately the same duration of magma gene ration and by a regional distribution of volcanic activity.
    Ocean island tholeiites are chemically intermediate between Hawaiian tholeiites and Hawaiian alkalic basalts (typical hot-spot type in the Pacific Ocean). Potassic nephelinites are characterized by containing amphiboles and biotites as xenocrysts and ph enocrysts but never containing tectonized xenolithic peridotites. Moreover, compared to Hawaiian post-erosional lavas the potassic nephelinites have higher Al2O3 content and K2O/Na2O ratio. Also there are no garnets and pyroxenes enriched in Ca -Tshermak or jadeite molecule which are stable under high pressure. Therefore the potassic nephelinites might be generated at shallower depth than Hawaiian posterosional lavas.
    Ocean plateau tholeiites are chemically distinguished from ocean ridge tholeiites (typical abyssal tholeiites) by their higher FeO*/MgO ratio and lower TiO2 conten and by being quartz-and strongly hyperthene-normative. From these evidences, the basaltic liquids of the ocean plateau tholeiites might be generated at shallower depth (<5 Kbar) than ocean ridge tholeiites. While, it is different from the Hawaiian tholeiites of typical hot-spot type with lower K2O and TiO2 content. Consequently these two volcanic suites erupted during the Cretaceous are different from ocean ridge volcanics and also from Hawaiian hot-spot volcanics.
  • 加藤 誠
    1980 年 89 巻 3 号 p. 198-200
    発行日: 1980/06/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 小林 貞一
    1980 年 89 巻 3 号 p. 201-205
    発行日: 1980/06/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 浜田 隆士
    1980 年 89 巻 3 号 p. 206
    発行日: 1980/06/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 松田 磐余
    1980 年 89 巻 3 号 p. 207-208
    発行日: 1980/06/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 小林 貞一
    1980 年 89 巻 3 号 p. plate1-plate2
    発行日: 1980/06/25
    公開日: 2010/12/22
    ジャーナル フリー
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