The Quaternary Research (Daiyonki-Kenkyu)
Online ISSN : 1881-8129
Print ISSN : 0418-2642
ISSN-L : 0418-2642
Search
Advanced search
OR
Browse
Search
Volume 53, Issue 3
Displaying 1-4 of 4 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
The Paper for the 2012 Japan Association for Quaternary Research Academic Award
  • Research on Quaternary mammal faunas in Japan and adjacent East Asian areas : A review of my research
    Yoshinari Kawamura
    2014 Volume 53 Issue 3 Pages 119-142
    Published: June 01, 2014
    Released on J-STAGE: October 24, 2014
    DOIhttps://doi.org/10.4116/jaqua.53.119
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    This paper reviews my research mainly on Quaternary mammal faunas in Japan and adjacent East Asian areas. My research career was ironi-cally initiated by stratigraphic works on Pleis-tocene sediments barren of mammal fossils in central Japan. Such works have been followed by studies on mammal fossils mainly from Quaternary fossiliferous localities and archae-ological sites all over Japan as well as foreign countries. Many systematic papers of mine have been published to describe the fossils, and some of them include discoveries of new forms. On the other hand, the experience of my research activities at many American and European re-search institutions has enhanced the quality of my research.
    My research is highlighted by such topics as biostratigraphy of Quaternary mammals in Japan, models for mammal immigration from the continent to mainland Japan, land bridge forma-tion in and around Japan and its image, the ice bridge hypothesis across the Tsugaru Strait, a hypothesis of “wooded Japan with mild environ-mental changes”, the boar rapid increase event, paleogeography of the Ryukyu Islands and hu-man immigration onto the islands, and the late Quaternary extinctions. Finally this paper des-cribes my activities for diffusing scientific knowledge related to my research, and contribu-tions to science education in schools.
    View full abstract
    Download PDF (2206K)
Articles
  • Changes in sedimentary environment and sedimentation rate of the IK1 core obtained from the inner part of Ishikari lowland, northern Japan
    Yuji Ishii, Ayana Ito, Toshimichi Nakanishi, Wan Hong, Kazuaki Hori
    2014 Volume 53 Issue 3 Pages 143-156
    Published: June 01, 2014
    Released on J-STAGE: October 24, 2014
    DOIhttps://doi.org/10.4116/jaqua.53.143
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Sedimentary environment and sedimentation rate of the Ishikari floodplain were investigated by analyzing borehole core sediments. The sedimentary environment changed from meandering river channel to floodbasin before 10,000calBP, and sedimentation rate increased around 8,000 calBP in response to the landward shift of the depocenter caused by sea-level rise. Sedimentation rate decreased largely after approximately 7,500 calBP in response to the deceleration of sea-level rise. Between 7,500 and 5,000calBP, the sedimentary environment was mainly occupied by floodbasin. Relatively successive peat had accumulated for 3,500 years after 5,000calBP under sea-level standstill. The timing of the decrease in sedimentation rate in the meandering fluvial system nearly coincides with that of the initiation of bayhead delta progradation in the barrier-lagoon system located just downstream of the meandering fluvial system. It is important to note that the evolution of meandering fluvial systems as well as of delta systems is influenced by the rate of sea-level change.
    View full abstract
    Download PDF (1800K)
  • Lithostratigraphy and dating of lacustrine sediment core (INW2012) from Lake Inawashiro-ko, Fukushima Prefecture, Japan
    Kotaro Hirose, Yoshitaka Nagahashi, Naomi Nakazawa
    2014 Volume 53 Issue 3 Pages 157-173
    Published: June 01, 2014
    Released on J-STAGE: October 24, 2014
    DOIhttps://doi.org/10.4116/jaqua.53.157
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Inawashiro-ko Formation is defined by a sediment core, INW2012 (drilling depth : 37.13m below lake floor (blf)) taken from the central part of Lake Inawashiro-ko, Fukushima Prefecture, Japan. The present study reports litho- and tephro-stratigraphy and results of AMS radio-carbon dating of the INW2012 sediment core. The Inawashiro-ko Formation is divided into three stratigraphic units : the Lower part (37.13- 26.60m blf) consisting of medium sand-sandy silt (vertically varied in grain size) with granule and wood fragments ; the Middle part (26.60-24.89 m blf) consisted of very fine sand-silt with a fining upward trend ; and the Upper part (24.89- 0.00m blf) composed of dense alternations of brighter and darker clay layers including clay-sand layers and tephra beds which are clearly distinguished from clay-dominant layers. The Lower part is of fluvial origin before formation of the lake. The Middle part was deposited during the initial stage of the lake formation, whereas the Upper part formed under deep-water condi-tions similar to the present lake. Six tephra beds can be correlated with previously reported tephras such as Aira-Tn (AT), Asama-Kusatsu (As-K), Towada-Chuseri (To-Cu), Numazawa-Numazawako (Nm-NK), Haruna-Futatsudake-Shibukawa (Hr-FA), and Haruna-Futatsudake-Ikaho (Hr-FP) tephras in chronological order. On the basis of 14C dating, Lake Inawashiro-ko formed at 42calkBP, and the sedimentation rate in the Upper part is estimated to be 0.3-1.0mm/yr.
    View full abstract
    Download PDF (1912K)
Lectures
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top