白駒池堆積物から推定される古環境

• 野末 泰宏

  信州大学理学部物質環境科学

• 福島 和夫

  信州大学理学部物質環境科学

• 公文 富士夫

  信州大学理学部物質環境科学

書誌事項

タイトル別名

• Paleoenvironment inferred from a sediment core of Lake Shirakoma

抄録

This study attempts to reconstruct the paleoenvironment of Lake Shirakoma, an oligotrophic-dystrophic lake located at high altitude (2115 m) in central Japan, based on the chemical analyses of a sediment core. A 94 cm core was taken in the center of L. Shirakoma at a water depth of 8m. The radiocarbon dating indicates that the average sedimentation rate is 0.21 mm y^-1. According to the observation of sediment facies, 0-47 cm depth is regarded as organic-rich mud, 47-70 cm as peat mud and below 70 cm as peat. The bottom peat layers containing much plant debris indicates that the former stage of this lake should be wetland, which was far shallower than the present state. The fact means that L. Shirakoma was formed 2200 years ago from a wetland. In the transition stage from a wetland to a lake, the water depth might be shallow and the in-lake productivity in water might be high, because of lower C/N atomic ratio and higher 4α, 23, 24-trimethyl-5α-cholest-22-en-3β-ol concentration at the layers. On the other hand, there are a few molecules indicative of land-plant inputs during the past 2200 years. Dehydroabietane and 18-norabieta-8, 11, 13-triene are detected both in an extant inflow stream and in the sediment from L. Shirakoma. Those abietane compounds may provide a tool to estimate the paleovegetation in the catchments.

収録刊行物

• 陸水学雑誌

  陸水学雑誌 66 (2), 81-92, 2005

  日本陸水学会

キーワード

• 白駒池
• 湖底堆積物
• 古環境
• 気候変動
• 分子指標

詳細情報

• CRID: 1390001204058678144
• NII論文ID: 130003645178
• DOI: 10.3739/rikusui.66.81
• ISSN: 18824897
• ISSN: 00215104
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可