Late Quaternary environmental changes as recorded by stable isotopes in a sediment core from Academician Ridge, Lake Baikal(Proceedingsof the 17^<th> Symposium on Researches Using the Tandetron AMS System at Nagoya University in 2004)

DOI IR HANDLE Open Access

Bibliographic Information

Other Title
  • バイカル湖湖底柱状堆積物を用いた第四紀後期における大陸内環境変動の復元(第17回名古屋大学タンデトロン加速器質量分析計シンポジウム平成16(2004)年度報告)

Search this article

Abstract

Variations in stable isotopic compositions of TOC, TN, TS and pyrite sulfur in the Lake Baikal sediment core (Ver98-1 St.5) are interpreted as proxies for climatic and environmental changes that can be of local, regional, and even global significance. Rapid δ^<34>S_<py> decreases at climate transition periods suggest that active sulfate reduction by SRB occurred at the water-sediment interface in the transition from cool to warm periods. This result implies that the [SO_4^<2->] increase and less oxic conditions took place in the climate transition periods. The rapid increase of precipitation with warming could give rise to the [SO_4^<2->] increase in the lake. The decrease of dissolved oxygen concentrations at sediment surface could be caused by the weakening of deep water ventilation. Also, δ^<15>N_<TN> excursions suggest low vertical mixing and low nutrient condition in these periods. Fluctuations of lake water circulation and depositional conditions correspond to global climatic and environmental changes.

Journal

Details 詳細情報について

Report a problem

Back to top