第四紀研究
Online ISSN : 1881-8129
Print ISSN : 0418-2642
ISSN-L : 0418-2642
10 巻 , 3 号
選択された号の論文の11件中1~11を表示しています
  • 垣見 俊弘, 平山 次郎, 岡 重文, 杉村 新
    1971 年 10 巻 3 号 p. 81-91
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
    Minami-Shitaura fault is an almost vertical fault and 60km south of Tokyo, trending WNW to ESE across the Miura Peninsula. The upper Miocene Hatsuse formation shows a flexure along the fault, in which the southern side of the fault subsided about 500m relatively and a fault plane, along which the same side was uplifted about 250m relatively to the northern side. If we give appropriate absolute ages to four horizons in the middle and upper Pleistocene formations, we can obtain the rates of displacements as 10 to 30cm/103 years, in which the southern side has been uplifted relatively. If we assume the uniform rate back to the time when the faulting changed from subsidence to uplift of the southern side, the time should be one or two million years ago. The rate of right-lateral displacement seems to have become to predominate far over the rate of vertical one at least since the late Pleistocene, on the basis of the offset of stream courses, ridges, and terrace scarps.
  • 大森 昌衛, 礒辺 大暢, 真野 勝友, 犬塚 則久, 成田層の古環境団研グループ
    1971 年 10 巻 3 号 p. 92-97
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
    In March of 1971, the writers had an opportunity to find and excavate the skull of the fossil elepahnt at Saruyama, Shimohusa-machi, Katori-gun, Chiba Prefecture. That skull was unearthed to be in the state of lacking the lower jaw bone and the most part of both tusks, but it could be identified that the material belonged to Elephas namadicus naumanni MAKIYAMA.
    The material was lain under overturned position in fine-gained sandstone which was assignable to the upper part of the Yabu formation of Upper Pleistocene. Immediately above the location of the fossil skull, about 20cm high, there was overlying fossil enclosure composed of abundant molluscan fossils which belong to the Lower part of the Narita formation of the younger. The details of the paleontological and the paleoecological studies are keeping up now.
  • 星埜 由尚
    1971 年 10 巻 3 号 p. 99-109
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
    宮崎平野においては, 後期新生界及び, 段丘地形の発達が良好である. 1930年代以降, 宮崎平野の地形及び地質の研究が行なわれてきたが, 従前の研究においては, 中新世後期から鮮新世前期の宮崎層群を切る谷を埋め, 段丘堆積物に不整合に覆われる堆積物 [大塚 (1930, 32) の通山浜層, 竹山 (1934) の仲間原泥層, Endo (1968) の川南層群が存在すると考えられてきた.
    一方, 筆者の調査によると, 宮崎平野の段丘面は次の様に分けられる. 即ち, 上位から, 先茶臼原面, 茶臼原面, 三財原面, 新田原面, 川南原高位面, 川南原低位面群, 日向シラス面, 三日月原面群である.
    本論文においては, いわゆる通山浜層と, 段丘面の海面の相対的変動に関連した発達史の問題点に就いて述べたい.
    いわゆる通山浜層については, その層相や, 段丘堆積物との関係, 及び, 川南原高位面下における, いわゆる通山浜層から産出した木片の14C年代測定結果からみて, 茶臼原面下のもの, 三財原面及び新田原面下のもの, 川南原高位面のもの, と三分される.
    川南原高位面は, 面を作る堆積物の層相と地形的特徴とからみて, 海成面であろうと思われる. 三財原面も, その分布上の特徴や, 堆積物の層相からみて海成面である. これら二つの面下に存在するいわゆる通山浜層は, それぞれ, これらの面の形成にかかわった海進時の堆積物であると考えられる. 川南原高位面を構成している堆積物 (川南原層: 本論文中で, いわゆる段丘堆積物といわゆる通山浜層とを併せたものとして定義する。) 中の砂質シルト層中に産出した木片の14C年代測定の結果, 26,100年±900年B.P. (GaK-3326) という年代が得られた. この絶対年代からみて, 川南原高位面は最終氷期中の亜間氷期に形成された可能性がある. 三財原面は海退過程で完成されたと思われる. 新田原面はその海退の後の海水準安定期に形成されたのであろう. 日向シラス面は川南原高位面形成後の海退時に, 大淀川流域に流入したシラス (入戸火砕流) の作る面である. シラスの絶対年代に関しては, 次のC14年代を得た. 即ち, シラス直下の暗色腐植質泥土層の29,600+1800 -1400年B.P.(GaK-2621) とシラス直上の軽石層 (第2オレンジ軽石層) 中の木片の25,600±1300年B.P.とである. 三日月原面群は最終氷期の最大海退時の産物であろう.
  • 野上 道男
    1971 年 10 巻 3 号 p. 110-112
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
  • 多田 文男
    1971 年 10 巻 3 号 p. 115-116
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
  • 佐々木 竜男, 片山 雅弘, 富岡 悦郎, 佐々木 清一, 矢沢 正士, 山田 忍, 矢野 義治, 北川 芳男
    1971 年 10 巻 3 号 p. 117-123
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
    Although many serveys and studies on the distribution and stratigraphy of tephras in Hokkaido have been done during last 50 years or more, the chronology on these tephras has not yet been correctly established. The authors have carried out the absolute chronology by dating with 14C on humified tephras in Hokkaido and made the correlation between each tephra. Moreover, they have tried to estimate the geological age of humus formation in these humified tephras. The chronology and the correlation of tephra layers in Hokkaido are as shown in Table 3, based on the 13C ages for humified tephra layers, as well as on some archeological data. Results obtained are summarized as follows;
    (1) In Hokkaido it seems that the age in which the remarkable humus have accumulated on tephras is not older than the earliest stage of the Holocene-about 8000 years ago.
    (2) Especially abundant accumulation of humus on tephras may have occured during 5000y.B.P. and 3000y, B.P. Perhaps the climate would have been rather humid and suitable for humus accumulation during this period. So called“Rodo”(humic volcanic ash soil) in Hokkaido is thought to have been farmed in this period.
    (3) The reddish-brown color of weathered pumices in Ta-d, Ma-k, Ma-d1 and Ko-f tephras may be due to the weathering under the past warmer climate than present. These periods are estimated about 7000 years ago for the former two and 3000-2500 years ago for the latter two.
  • 多田 文男, 長沼 信夫, 阿由 葉元, 角田 清美, 市瀬 由自, 小林 和子
    1971 年 10 巻 3 号 p. 124-133
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
    This paper consists of a historical review on the formation of sand dunes and some considerations on the relationship between the dune formation and the intercalated humus layers in several districts. The following results were obtained;
    (1) Buried dunes beneath the surface of Tatebayashi upland in Tochigi Prefecture.
    Sand layers constituting the buried dunes are divided in two, both having been deposited under stable circumstances. And volcanic ash layers are found in this district, divided into three; upper, middle and lower. There is every reason to believe that these dunes were formed at the beginning of the fall of the middle ash, or at the end of that of the lower ash.
    (2) Sand dunes on Sanrihama and Kaetsu uplands.
    The formation of some of Sanrihama dunes were due to a relative rising of sea level in early Holocene epoch. At the bottom of shallow valleys in Kaetsu upland, humus accumulation occured in stagnant water prior to the formation of dunes.
    (3) Kashima dunes in Ibaragi Prefecture.
    In the Kashima peninsula are found sand dunes with three intercalated humus layers, which are thought to have been formed after the formation of sand bars caused by a rise of sea level during the Jomon culture period, early Holocene.
    (4) Genkai dunes in Fukuoka Prefecture.
    Sand dunes of this area were formed during the time of high sea level in Pleistocene epoch. Aeolian sand layers are thin in depth and cover uplifted sand bars of marine deposits forming coastal terrace topography. Furthermore, five buried humus layers called Kurosuna are found among sand beds of Holocene dunes, which indicate the ages of dune formation and the stable period.
  • 藤 則雄
    1971 年 10 巻 3 号 p. 134-146
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
    Palynological, stratigraphical and chronological investigations were made on the Holocene buried humus soils intercalated in the coastal sand dunes developed along the Japan Sea in the Hokuriku district, Central Japan.
    The purpose of the present investigations is to determine a definite age of the formation of the humus soils, palaeoclimatic condition under which they were formed, their topographical environments and the relationship between the formation of their humus soils and coastal sand dune and the cahnge of sea-level.
    Most of the studied humus soils and peat deposits are considered to have formed during the close of the Middle Jomonian to the Early Old Tomb periods. The conclusion are based on 14C dating, the stratigraphy, topographical setting and archaeological remains found in the humus soils.
    The palaeoclimatic condition at those periods was cool temperate, judging from such macroplant remains as erect tree stumps, leaves and seeds, and microplants as pollen grains and spores. The annual mean temperature was estimated at some 11°C, and the flora which was developed on the Inner and Middle or Old sand dunes was composed mainly of either a riparian or a mixedslope type, being closely similar to the present lowland vegetation in the northern Honshu.
    A relative minor rise of the sea-level and migration of the coastal sand dunes seem to have caused the formation of most of the buried humus soils and peat which is called Sotan in Japanese, and submerged and buried forests in the coastal areas of the Japan Sea, Hokuriku district, Central Japan.
  • 菅野 一郎
    1971 年 10 巻 3 号 p. 147-150
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
    The humus contents and the Ch/Cf ratios of fifteen Humic Allophane soils were very high and the humus composition was characterized by the predominance of fraction 1 and low contents of fraction 2 and humins. The Ch/Cf ratios of Humic Allophane soils have certain geographical regularities. In Japan the ratios generally increase from the north to the south. Though the former contains a considerable amount of amorphous aluminosilicates dissolved by the Tamm's reagent, Altered Humic Allophane soils should be distinguished from Humic Allophane soils by the predominance of 14Å minerals and kaolin minerals. The Ch/Cf ratios of nine Altered Humic Allophane soils are higher than those of Humic Allophane soils, but the aromatic nature of the humic acids is almost the same as that of Humic Allophane soils. If Altered Humic Allophane soils were of the hydromorphic origin, their humic acids would not have such a high degree of aromaticity. The humic acids of normal and Altered Humic Allophane soils can be distinshished from those of Red-Yellow soils by their high Ch/Cf ratios and aromatic nature. Therefore, the forming process of the humus of Altered Humic Allophane soils is different from that of geographically associated Red-Yellow soils, but closely resembles that of Humic Allophane soils. This is the reason why Altered Humic Allophane soils should be regarded as a subtype of Humic Allophane soils.
  • 熊田 恭一, 太田 誠一
    1971 年 10 巻 3 号 p. 151-158
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
    アロフェンおよびアルミニウムの役割に着目した腐植土生成機構に関するモデル実験として, 下記の土壤 (C層) の存在のもとでおこるピロガロール, カテコールおよびヒドロキノンの褐変反応を分光光度法によって調べた.
    天文台: 腐植質火山灰土, 主な粘土鉱物, アロフェン, 善師野: 強酸性赤黄色土, モンモリロナイト, 東山: 酸性赤黄色土, カオリン鉱物,
    天文台および善師野土壤の存在のもとでは, アルミニウムとプルプロガリンおよびカテコールに由来する未知物質ならびに鉄とカテコールからなる錯化合物の生成が認められた. これらの錯化合物および褐変物質の生成とそれらの土壤への吸着は, 天文台, 善師野, 東山の順に前者ほど大きいことが推論された. 用いたポリフェノールのうちでは, ヒドロキノンが最もよいモデル物質であると考えられる.
  • 宮崎 明子
    1971 年 10 巻 3 号 p. 159-164
    発行日: 1971/10/30
    公開日: 2009/08/21
    ジャーナル フリー
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