The Quaternary Research (Daiyonki-Kenkyu)
Online ISSN : 1881-8129
Print ISSN : 0418-2642
ISSN-L : 0418-2642
Volume 36, Issue 3
Displaying 1-5 of 5 articles from this issue
  • Sumiko Kubo
    1997 Volume 36 Issue 3 Pages 147-163
    Published: July 31, 1997
    Released on J-STAGE: August 21, 2009
    JOURNAL FREE ACCESS
    The Sagami River mouth faces the Sagami Trough without a distinct continental shelf, and the lower Sagami plain has well-developed marine and fluvial terraces. This area is also favorable for interpreting the tephrochronology of the Last Glacial Cycle using tephras from Fuji and Hakone volcanoes. The subaerial terraces and their constituent deposits in the lower Sagami plain correspond to the Marine Isotope Stages (MIS) 5c-5a (S1-S3 terraces), 3 (N and T) and 2 (M), respectively.
    The buried terraces were examined by bore-hole logs and correlated with subaerial ones in the upper reaches using morphological continuity and tephra sequence lying on the terraces. These buried terraces and deposits correspond to the MISs 5a, 4, 3, and 2, based on tephrostratigraphy.
    The landform development of the lower Sagami plain since the MIS 5a is as follows: A broad fan-deltaic plain was formed in the culmination of the MIS 5a. A deep and narrow valley incised the plain during the MIS 4, because of the sea-level drop. During the MIS 3, this deep valley was filled, and a relatively wide plain of compound fans developed. A deep and narrow valley was formed again in the MIS 2. Sagami Bay has intruded into the lower Sagami plain in the MIS 1.
    Relative sea-level changes are shown by subtracting tectonic components from the observed heights of buried terraces near the present river mouth. The tectonic component (average uplift rate) is estimated to be 0.07m/ky near the present river mouth. The calculated sea-level height at the culmination of each stage was as follows: -30 to -40m in the MIS 5a, ; -95 to 110m in the MIS 4; -80 to -90m in the MIS 3; and -100 to -110m in the MIS 2. These results suggest a low sea level for the MIS 4 and that a relatively low sea-level remained throughout the MIS 3.
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  • Hideaki Oshima, Shigemoto Tokunaga, Koichi Shimokawa, Kiyohide Mizuno, ...
    1997 Volume 36 Issue 3 Pages 165-182
    Published: July 31, 1997
    Released on J-STAGE: August 21, 2009
    JOURNAL FREE ACCESS
    Pollen stratigraphy, tephrochronology, and correlation to oxygen isotopic records were examined on bottom cores from GS400 (400m long) and 63B (200m long) sites in Lake Suwa, Nagano Prefecture, Japan. The tephras of Pm-I', Pm-I, Pm-II, Aso-4, Pm-III, and AT are intercalated in the middle to upper horizons. From the results of pollen analysis, the sediments are divided into ten pollen zones, SUWA-I to SUWA-X in ascending order. In SUWA-I, IV, VI, VIII-IXa, and IXc-X pollen zones, sub-arctic conifers such as Picea, Tsuga, Abier, and Haploxylon are dominant. In SUWA-II-III, V, VII and IXb zones, which occur between the subarctic zones, however, temperate conifers such as Cryptomeria, Sciadopitys, Taxaceae-Cephalotaxaceae- Cupressaceae and deciduous broad-leaved trees of Fagus, Carpinus-Ostrya, Lepidobalanus, and Ulmus-Zelkova prevail.
    These cyclic changes of pollen flora show a repetition of five cool and four warm periods during middle to late Pleistocene times, 185ka to >25ka, as deduced by tephrochronology. Each period corresponds to stages 6 to 2 by δ18O (Martinson et al., 1987), as follows: SUWA-I--stage 6, II-III--5e, IV--5d, V--5c, VI--5b, VII--5a, VIII--4, IX--3 and X--2.
    The SUWA pollen zones are correlated to those of the coeval sediments in Lakes Nojiri and Biwa as follows (Suwa, Nojiri and Biwa are abbreviated as S, N, B): S-V-VII--N-Cryptomeria zone, S-VIII--N-Pinaceae zone, S-IX--N-Larix-Betula zone to Quercus-Fagus zone and S-X--N-Picea-Abies-Tsuga zone; S-I--B-X, S-II-III--B-XI, S-IV--B-XII, S-V--B-XIII, S-VI--transitional part of the B-XIII and B-XIV, S-VII-VII--B-XIV, S-IX--B-XV and S-X--B-XVI.
    The Suwa palynostratigraphy shows correlation to the oxygen isotopic records and can be used as a standard for palynologycal correlation of the middle to late Pleistocene in Central Japan.
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  • Masaaki Shirai, Ryuji Tada, Kantaro Fujioka
    1997 Volume 36 Issue 3 Pages 183-196
    Published: July 31, 1997
    Released on J-STAGE: August 21, 2009
    JOURNAL FREE ACCESS
    Widespread tephras correlated with Aso-4, Toya, Aso-3, and B-Og have been previously reported from the Shibikawa and Katanishi Formations at the Anden Coast, Oga Peninsula. Among these tephras, identification of Aso-3 is questionable considering the distribution of Aso-3 in NE Japan. B-Og, on the other hand, is reported only from Oga Peninsula, and its age is not yet defined.
    In order to revise the tephrochronological stratigraphy at the Anden Coast, the authors analyzed the major elements, compositions and refractive indices of volcanic glasses for these tephras and compared the results with the representative values. We also analyzed the major elements, compositions, and refractive indices of tephras in the upper Quaternary sediments of the Sea of Japan recovered from ODP Sites 794 and 797, where δ18O stratigraphy is established. Our results suggest that the tephra previously correlated to Aso-3 at the Anden Coast is different in FeO* and CaO contents from Aso-3 but is indistinguishable in composition from Aso-1 (rich in FeO*, CaO, Na2O and K2O). Tephras with similar composition were found at Sites 794 and 797, and the ages of both are estimated as about 255ka (isotope substage 8b). This age is consistent with the age of Aso-1, which further supports our correlation of these tephras to Aso-1.
    Tephras whose compositions are similar to B-Og (rich in FeO*, Na2O and K2O) are also found at ODF Sites 794 and 797, at 5 horizons whose ages range from 419ka to 538ka. Taking into account the distribution of these tephras and the low sea level at the time of B-Og deposition at the Anden Coast inferred from sedimentary facies analysis, we conclude that the tephra corresponding to isotope substage 12b (about 448ka) is probably correlated to B-Og.
    Based on these results, the age for the base of the Shibikawa Formation, which has previously been considered to be about 300ka, is estimated as older than 450ka. Thus, our results significantly revise the chronostratigraphy of the upper Quaternary at the Anden Coast, one of the type localities on the Japan Sea side of NE Japan.
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  • Shinji Kato
    1997 Volume 36 Issue 3 Pages 197-206
    Published: July 31, 1997
    Released on J-STAGE: August 21, 2009
    JOURNAL FREE ACCESS
    In North China, blades were first produced about 32, 000yrs B. P. There were two conditions for the appearance of blade technique. One is represented by blades from Shuidonggou(_??__??__??_), Ningxia province, which are distinguished by the presence of a tabular core and a scraper on the blade. Based on the technological resemblance between Shuidonggou and Mousterian objects in North Asia, it is assumed that the two cultures were related, and techniques were diffused from North Asia to North China with the change of cultural area.
    The other set of conditions is represented by blades from Shiyu(_??__??_), Shanxi province, which are related to North Chinese Middle Palaeolithic cultures. Stone tools were used, and surviving blades are relatively few in number in this area. Based on archaeological records, three stages of the emergence of blade technique are hypothesized for this set of conditions. The first stage is represented by late Middle Palaeolithic industries such as those from Liujiacha(_??__??__??_), Gansu province. The technological foundation for blade technique was formed in this stage. The next stage is represented by Xinmiaozhuang(_??__??__??_), Hebei province. The blades produced in this stage were relatively wide, and were not used in tool making. Blades in the third stage were used for tools. The representative site is Shiyu. It is assumed that this sequence of stages illus trates the domestic development of palaeolithic technology in North China.
    In the Korean Peninsula and the Japanese Islands, blade industries appeared about 30, 000yrs B. P. Those blade techniques are similar to those of Shiyu, and younger than those of North China. It may be supposed that blade techniques in Korea and Japan spread from North China with the movement of human groups. At the same time, there are many differences between palaeolithic cultures in these three areas, and the domestic development of blade technique is also observed in the archaeological records of Japan. Thus, if there was cultural diffusion around East Asia in the early Upper Palaeolithic age, its influence was relatively limited; the main origin of Upper Palaeolithic culture in each area of East Asia was the domestic development of techniques that progressed independently.
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  • Toshiko Okada
    1997 Volume 36 Issue 3 Pages 207-213
    Published: July 31, 1997
    Released on J-STAGE: August 21, 2009
    JOURNAL FREE ACCESS
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