第四紀研究
Online ISSN : 1881-8129
Print ISSN : 0418-2642
ISSN-L : 0418-2642
1 巻 , 1 号
選択された号の論文の5件中1~5を表示しています
  • 長谷部 言人
    1957 年 1 巻 1 号 p. 1-7
    発行日: 1957/05/30
    公開日: 2009/08/21
    ジャーナル フリー
    Human action is not different from that of non-human animals in the point that it is the movement of bodily parts by muscle power. It has, however, been specialized in various aspects such as gestures, languages, techniques, arts, sports, and so on, and besides has played a great role as something like a source power relevant to the emergence of mankind as special beings distinguished from other primates. From the above point of view the writer would emphasize the significance and neccesity of ergology, the science of action, in relation to the phylogenetic study of man.
    Most of the primitive features of the skulls of early fossil Hominidae may be explained, to a great extent, as phenomena corresponding to the powerfulness of biting mechanism. Those primitive features were well manifested in Australopithecus, became most prominent among Paranthropus and Meganthropus in Early Pleistocene, less prominent among the Pithecanthropus-Sinanthropus group of the Middle Pleistocene age, and had been preserved to some extent till Late Pleistocene, the age of Homo primigenius. But those features disappeared among Homo sapiens fossilis in the end of Pleistocene.
    The unique nature of the transformation of human cranium showing its peak in Early Pleistocene may be explained in relation to the appearance of early crude tools. In early times from the age of Australopithecus to that of Pithecanthropus and Sinanthropus human dentition must have been the most useful organ as a kind of working tool with superior cutting function. The reason why there should have been a great deal of need and opportunity for Early Pleistocene Hominidae to use their dentition as a kind of working tool is that though some kind of crude tool such as pebble-tool has been made and used by those early men, its efficiency was necessarily less greater than that of core- and flake-tools made and used by later Hominidae. The degree in the heavy use of human dentition seems to have been decreased in accordance with the development and specialization of working tools from Middle Pleistocene onwards.
    The same mode of life as that of his parents might affect a person's individual bones to modify in the same way so that it may seem as if to be hereditary. But it is actually not. Provided that the transformation of human cranium previously mentioned is the result of working of the above process throughout a long period of time, it may not be called evolution but modernization, that is the transformation caused by the effect of changing mode of human life. The appearance of platycnemy among Homo sapiens fossilis and remarkable increase in the average hight of females in modern times can also be regarded as the result of modernization.
  • 永田 武, 秋本 俊一, 上田 誠也, 清水 吉雄, 小島 稔, 小林 和男
    1957 年 1 巻 1 号 p. 7-10
    発行日: 1957/05/30
    公開日: 2009/08/21
    ジャーナル フリー
    A palaeomagnetic study has been conducted of the volcanic rocks in the North Izu-Hakone volcanic region, Japan, where the complete succession of lavas has been determined by H. Kuno. By sampling 4∼7 oriented rock-specimens at each of the localities, the period from the very beginning of the Pleistocene to the Holocene has been covered, where the maximum time interval between consecutive samples may probably be not more than several tens of thousands years except that between two samples of middle to younger Pleistocene when the volcanic activity did not occur within the region concerned. Care was taken not to use the rock samples of which natural remanent magnetization may have suffered from any significant disturbances, geologically, chemically, magnetically or otherwise. Selection of proper samples was performed according to the criteria for the stability of remanent magnetization proposed by us previously (Journ. Geomag. Geoelec., VI, No.4). The major findings in this study are: 1) During the whole Quaternary age, the axis of the geomagnetic centred dipole was fluctuating around an axis of which north pole changed from φ=72°N, λ=86°E to φ=81°N, λ=32°W. 2) The direction of polarization of the centred dipole was reversed at a time in the earliest Quat rnary, namely, during the middle period of the formation of the Usami volcano.
  • 小池 清, 成瀬 洋
    1957 年 1 巻 1 号 p. 11-17
    発行日: 1957/05/30
    公開日: 2009/08/21
    ジャーナル フリー
    1. At Isone, Osawa-Machi, Chiba Prefecture, an unconformity between the Nagahama formation and the underlying Nakazeki formation (≈Iwasaka formation) has been newly recognized (Fig.1). The relation between the two was formerly regarded conformable. Thus it is proved that stratigraphic column from the upper part of the Otadai formation through the Kakinokidai formation (≈Akimoto group) in the east coast of the Boso Peninsula is lacking in the west coast (Fig. 2).
    2. Several rock fragments dredged at the Nakanose Bank off Yokohama were examined, and the submarine topography was studied. The results suggest that the rocks of the Nakanose Bank belong to the Miura group.
    3. Based on the above-mentioned facts and comparison of lithic character and fossil-coenosis, the writers have correlated the late Cenozoic strata on both sides of the Tokyo Bay as follows:
    4. Two different opinions have been expressed concerning the stratigraphic position of the Plio-Pleistocene boundary. One draws it at the base of the Tsurumai group, and another at the base of the Akimoto group in the Boso Peninsula. In either case, however, the above-mentioned boundary is represented by the base of the Nagahama formation in the Boso Peninsula, and by the base of the Koshiba formation in the Miura Peninsula.
  • 相沢 忠洋
    1957 年 1 巻 1 号 p. 17-22
    発行日: 1957/05/30
    公開日: 2009/08/21
    ジャーナル フリー
    In the fall of 1947, the author noticed the fact that the unknown stone industries without earthenwares are buried in the so-called Kanto-loam beds at Iwajuku, Kasakake village, Gunma prefecture, northern Kanto district. Subsequent investigations assured us that these buried industries represent the non-ceramic or the pre-Jomon culture of Japan. As a result of the author's archaeological research in this region, it has been shown that the non-ceramic culture is divided into four different stone industries; namely, the microlithic, the point, the blade and the hand-axe industries. From a stratigraphical point of view, on the other hand, three beds of loam (upper, middle and lower) occur in the northern Kanto district. A correlation between the archaeological and geological records seems to be as follows;
    It will certainly be significant that in the Akagi region, the point iudustry is usually found from the upper loam, while the hand-axe industry in the middle or the upper part of the lower loam.
  • 貝塚 爽平
    1957 年 1 巻 1 号 p. 22-30
    発行日: 1957/05/30
    公開日: 2009/08/21
    ジャーナル フリー
    1. 武蔵野台地は, 地形面の連続性と関東ローム層によつて, 下末吉面, 武蔵野面, 立川面およびそれ以下の段丘に大別される. これら各面をつくるものは, 武蔵野面および下末吉面の東京山の手地域にあるものをのぞくと, いづれも礫層であつて, これらの礫層よりなる各面は, 主として多摩川の作つた扇状地である.
    2. これら各面の縦断面形の比較と武蔵野面の等高線異状の考察から, 武蔵野台地の北部は北東に傾き下る撓曲をうけて変形したことが明らかにされた. この変動は大宮台地には及んでいない. また, 古い地形面ほど大きい変形を示すことから, この運動が継続的なものであることが知られる.
    3. 洪積世末期には, 武蔵野台地の南部から松戸附近の下総台地に至るほぼ東西の軸を境として, これ以北では関東平野の中心部に向う造盆地運動がありこれ以南では, とくに房総半島北部の地形に著しくあらわれている東京湾の低地を作る沈降運動が行われた.
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