地学雑誌
Online ISSN : 1884-0884
Print ISSN : 0022-135X
ISSN-L : 0022-135X
88 巻 , 5 号
選択された号の論文の9件中1~9を表示しています
  • 川辺 鉄哉, 福田 鉄雄, 川畑 憲之, 前田 四郎
    1979 年 88 巻 5 号 p. 281-295
    発行日: 1979/10/25
    公開日: 2009/11/12
    ジャーナル フリー
    The sedimentation of the base, litho-facies near the base, the key bed and the sedimentary environment of the formation, were studied on the Kurotaki Formation, which is distributed from the Minato river-section in the west, to the Obitsu river-section in the east, over the Boso Peninsula.
    1) The Kurotaki Formation lies on the Anno Formation unconformably at most places, for instance, the Takamizo-section, northern Mitsuishi mountain-section where the basal part of the formation varies its litho-facies and contains fossiliferous and impure limestone.
    2) Two types of litho-facies were recognized in the formation except at the basal conglomerate. One is the silty sandstone facies intercalated many tephras, the other is the massive tuffaceous sandstone facies that is very rare of tephra. Both facies are rhythmically repeated from the lower horizon to the upper one and useful for the observation of the correlation of the formation in the area.
    3) 2 set of tephras which had hitherto been known as Kd 23 (_??_TM 1) and Kd 38 (_??_TM 3) in the area were investigated. As the result, it is clear that the former does not continue at a few sections, but the later continues roughly.
    4) Except above 2 tephras, 5 new tephras, namely TM 2, TM 4-7 in descending order were found. Among them, TM 2 consisting of coarse-grained scoria is most important as a key bed because this tephra ranges horizontally so long all over the area.
    5) The beginning of the deposition of the formation in this area was roughly the same period. But more exactly speaking, from the distribution of new tephra TM 4-7, the sedimentation of the basal part of the formation was formed in different time.Therefore it is assumed that the Kurotaki transgression might be brought to fill up the depressed ground which had been formed by folding before the Kurotaki transgression.
    6) Judging from the tephra of TM 3-7, the Mitsuishi mountain area was the land until the beginning of the deposition of TM 3.
    7) After the deposition of TM 3, the area surrounding the western and eastern sides of the Sasa river-section was deposited in the deeper sea than the Mitsuishi mountain area was.
    8) We knew by the litho-facies that the eastern part of the surveyed area was deeper in the sea than the west area, when TM 1, 2 were deposited.
  • 田宮 兵衛
    1979 年 88 巻 5 号 p. 296-312
    発行日: 1979/10/25
    公開日: 2009/11/12
    ジャーナル フリー
    After the discovery of the stratospheric sudden warming by SCHERHAG (1952) over Berlin much meteorological efforts have been directed to make clear the phenomenon in lower stratosphere of winter hemisphere.
    There can be no doubt that the studies of the four major warmings in the Northern Hemisphere, occured during 1956/57-1967/68, play the important part in the advance in knowledge of the phenomena.
    These studies are sorted in table 1 by period and approach which are classified (1) synoptic description, (1') analytical study, (2) energetics and (3) modeling. In the table winters are indicated in such manner as 1957/58.
    Researches of energetics, in most of which calculations in the wave number domain are based on the SALTZMAN's method (1957), began to investgate the instability of polar vortex. They, however, revealed that the energy for polar vortex breakdown and for reversal of temperature field are transported from troposphere mainly as geopotential flux. But the physical mechnism of the breakdown and the reversal must be explained by model simulation.
    MATSUNO's (1971) and NEWSON's (1974) model simulate successfully stratospheric sudden warmings in 1962/63 and 1972/73 respectively. That means that warming occures with upward propagation of planetaly waves (Charny and Drazin, 1961). Therefore it is possible that warmings happen every winter in the level higher than upper stratosphere. The reason why some of them leads to polar vortex decay in the lower stratosphere and others remain in upper layer is not yet clear.
    Recent researches have owed its greater part to the developments in new observation techniques as rocket sonde and satellite. Papers based on the satellite data are summerized in table 2.
    Warming phenomena in upper stratosphere and mesosphere without marked effects on the lower stratosphere are cited in table 3.
    To answer the question whether in Southern Hemisphere major warming as in its counterpart occures or not, researches of Southern Hemispheric stratospheric warmings are listed in table 4 and examined. For the present we have negative answer.
    Finally in table 5 studies in climatological spects as well as of phenomena after the period of table 1 are given as supplement.
    Important problems remained today are :
    1. to establish three-demensional structure of the stratospheric sudden warming extending to the upper mesosphere with data from new technique, and
    2. researches on the relationship between stratospheric phenomena and troposphere are not yet sufficient, although its possibilities are expected through model experiments and discussed in many papers independently.
  • 町田 洋, 新井 房夫
    1979 年 88 巻 5 号 p. 313-330
    発行日: 1979/10/25
    公開日: 2009/11/12
    ジャーナル フリー
    The eruptions of the Daisen Valcano (35°22'N, 133°33'E) were mainly rhyodacitic and of the paroxysmal type, producing several extensive sheets of tephra. The Kurayoshi pumice (DKP, for short), one of the excellent Late Pleistocene markers arising from the Daisen valcano, is rhyodacitic in composition with abundant hornblende and orthopyroxene crystals and relatively small amount of biotite. Its identification can be made from the above mentioned mineral assemblages as well as from the characteristic refractive index of orthopyroxene (γ=1.703-1.708) and of hornblende (n2 = 1.673-1.682) and the specific crystal habit of orthopyroxene. This pumice-fall deposit occurs on marine and fluvial terraces in the San'in and Hokuriku districts facing the Japan sea and extends eastward beyond the Northern Japan Alps to north Kanto plain as a thinner discontinuous layer. Stratigraphic relation with the dated tephra layers in north Kanto indicates that the pumice was probably deposited between about 47, 000 and 45, 000 years ago. That is, this pumiceous deposit is found at the intermediate horizon between Yunokuchi Pumice (UP, slightly younger than 49, 000 YBP) and Hassaki Pumice (HP, 40, 000-44, 000 YBP) in north Kanto, about 500 km far from the Daisen.
    Daisen Kurayoshi Pumice wonld be particularly valuable for establshing chronological framwork as a fundmental time-marker in arears where no suitable markers have yet been documented. Moranic deposit of the Murodo glacial advance at Mt. Tateyama, Northern Japan Alps, is mantled by this marker and overlies the Raicho-dai pumice-fall deposit, products of the earliest stage of volcanic activity of Tateyama III, which is correlated with the Omachi EPm deposit approximately 60, 000 years old. Distribution of these two unreworked tephras indicates that major valley glaciers had nearly disappeared by the times of these initial tephra falls. The glacial advance at Mt. Tateyama, the most extensive of the advances during Last Glacial age, therefore, apparently culminated between about 55, 000 and 50, 000 years ago. On the other hand, a filltop terrace repesented by Uwadan terrace along the River Joganji flowing from Mt. Tateyama, is covered by DKP and is nearly younger than the pyroclastic flow deposit of Tateyama III. Accumulation of the river of Uwadan stage is, therefore, simultaneous and probably associated with the Murodo glacial advance.
  • 高橋 浩一郎
    1979 年 88 巻 5 号 p. 331-335
    発行日: 1979/10/25
    公開日: 2009/11/12
    ジャーナル フリー
    Recent considerations on climatic variations are reviewed and following points are summarized, (1) Distribution, influences on human society and causes of climatic variations is dependents of time scale of climatic variation. (2) Climatic system is composed of various elements and climatic status determined by delicate balance of these elements. (3) Increase of human consumption of fossil fuel brings increase of CO2 in the atmosphere. If such trends continues, marked change of climate will occur on the middle of next centuries.
  • 小林 貞一
    1979 年 88 巻 5 号 p. 336-337
    発行日: 1979/10/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 日本地学史資料調査委員会
    1979 年 88 巻 5 号 p. 338-352
    発行日: 1979/10/25
    公開日: 2010/04/23
    ジャーナル フリー
  • 松田 磐余
    1979 年 88 巻 5 号 p. 353-354
    発行日: 1979/10/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 五条 英司
    1979 年 88 巻 5 号 p. 354-355
    発行日: 1979/10/25
    公開日: 2010/04/23
    ジャーナル フリー
  • 佐藤 久
    1979 年 88 巻 5 号 p. Plate1-Plate2
    発行日: 1979/10/25
    公開日: 2009/11/12
    ジャーナル フリー
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