岐阜県高富低地湖沼堆積物の花粉分析による最終氷期初期からの植生・気候変遷 Vegetation and Climate History since the Early Last Glacial Period in the Takatomi Lowland, Gifu Prefecture, Central Japan

この論文にアクセスする

この論文をさがす

著者

抄録

高富低地には泥質の湖沼堆積物が厚く堆積し,西深瀬でボーリングしたオールコア試料には,阿蘇4(Aso-4),姶良Tn(AT),鬼界アカホヤ(K-Ah)の広域火山灰が挾まれる.最終氷期のMIS5b以降現在に至るオールコア約16mの堆積物試料の花粉分析をもとに,本地域における植生と気候の変遷を論じた.さらにMIS編年との対比を行い,他地域との対比と各時期の植生分布・古気候を考察した.花粉化石群集はTK-X~I帯に分帯された.MIS5bの時期には,アカガシ亜属<i>Quercus</i> subgen. <i>Cyclobalanopsis</i>などに示される暖温帯広葉樹林が覆っていて温暖湿潤な気候であった.MIS5aの時期には,スギ属<i>Cryptomeria</i>,コウヤマキ属<i>Sciadopitys</i>花粉が優勢となり,湿潤な気候であったことが推定される.MIS4になると,急激な寒冷化になり,マツ科針葉樹林が卓越した.その後のMIS3には,少し温暖化して冷温帯落葉広葉樹林が卓越した.約3.1万年前に再び急激な寒冷化と乾燥化が到来し(MIS2),亜寒帯針葉樹とカバノキ属<i>Betula</i>花粉が増大した.しかし,約1.4万年前には針葉樹花粉は急減し,コナラ亜属<i>Quercus</i> Subgen. <i>Lepidobalanus</i>など落葉広葉樹林が拡大して温暖化が始まる.後氷期中期にはモチノキ属<i>Ilex</i>花粉が卓越し,約3,000年前からはアカガシ亜属花粉が急増して暖温帯広葉樹林が成立した.太平洋側にある高富低地は,北陸地方とは違って,スギ属・コウヤマキ属が優占して湿潤な気候を示す時期はMIS5aのみであり,それ以外の時期は北陸地方よりも乾燥していたと考えられる.

The lacustrine sediments of the Takatomi Lowland include the widespread volcanic ashes called Aso-4, AT, and K-Ah derived from southern Kyushu. The sediments have been deposited continuously since the early Last Glacial Period, marine isotope stage 5b. Pollens from 16.5m boring cores of these sediments were analyzed to discuss the vegetation and climate history, to correlate MIS chronology, and to clarify the distributions of vegetation by correlating other site data at each age. The fossil pollen assemblages from the Takatomi Lowland sediments are divided into ten pollen zones, TK-I to X. At the age of MIS 5b, the Takatomi Lowland was occupied by warm temperate broadleaf forests of <i>Cyclobalanopsis</i>, and the climate was warm and wet. As the pollen grains of <i>Cryptomeria</i> and <i>Sciadopitys</i> were prevalent at the age of MIS 5a, it is thought that there was abundant precipitation. At the age of MIS 4, as the pollen grains of subboreal coniferous trees increase abruptly, it became colder and dryer. At the age of MIS 3, the climate became warmer than at the previous age as the pollen grains of cool temperate deciduous broadleaf forests prevailed. About 31, 000 years ago (MIS 2, full glacial period), the climate became dryer and colder suddenly, as shown by the pollen grains of subboreal coniferous trees and deciduous broadleaf trees such as <i>Betula</i> and <i>Corylus-Myrica</i>, which grow in the cool temperate zone. About 14, 000 years ago, as the pollen grains of coniferous trees disappeared abruptly, a warmer climate increased the pollen grains of deciduous trees such as <i>Lepidobalanus</i> and <i>Corylus-Myrica</i>. In the late glacial period, the pollen grains of <i>Ilex</i> prevailed, and since 3, 000 years ago the pollen grains of the warm temperate evergreen broadleaf forests of <i>Cyclobalanopsis</i> have prevailed. Comparing the pollen assemblage data from the Hokuriku District located along the Japan Sea, the Takatomi Lowland on the Pacific Ocean side was thought to be only at the age of MIS 5a, when the climate was humid as inferred from the presence of pollen such as <i>Cryptomeria</i> and <i>Sciadopitys</i>; but at other ages the Pacific Ocean side was dryer than Japan Sea side.

収録刊行物

  • 第四紀研究

    第四紀研究 41(6), 443-456, 2002-12-01

    Japan Association for Quaternary Research

参考文献:  45件中 1-45件 を表示

被引用文献:  2件中 1-2件 を表示

各種コード

  • NII論文ID(NAID)
    10010427951
  • NII書誌ID(NCID)
    AN0034136X
  • 本文言語コード
    JPN
  • 資料種別
    ART
  • ISSN
    04182642
  • NDL 記事登録ID
    6373045
  • NDL 雑誌分類
    ZM49(科学技術--地球科学--地質)
  • NDL 請求記号
    Z15-67
  • データ提供元
    CJP書誌  CJP引用  NDL  J-STAGE 
ページトップへ