硫黄および炭素の安定同位体を用いた生物大量絶滅を引き起こした環境変動に関する研究(2004年度日本地球化学会奨励賞受賞記念論文)
スポンサーリンク
概要
- 論文の詳細を見る
Environmental perturbations at mass extinction events are reviewed based on isotopic compositions of sulfur and carbon. Large negative excursions in marine carbonate δ^<13>C are commonly associated with mass extinctions. The δ^<13>C excursion after the Cretaceous-Teriary (K-T) boundary event has been linked to a collapse of the vertical carbon isotope gradient. As a vertical carbon isotope gradient is a function of photosynthetic productivity, the collapse of the isotope gradient implies cessation of photosynthesis. Some mechanisms for the decrease in sunlight after the K-T impact event were proposed so far, such as dust cloud, sulfate aerosol, and soot from global wildfires; however there is no consensus for the cause of the cessation of photosynthesis. Both two major events that can initiate mass extinctions, i.e., bolide impact and intense volcanic activity, should release sulfur-bearing gases into the atmosphere. Such gases should be converted to sulfate aerosol and, eventually, sulfuric acid rain, which raises sulfate concentration in freshwaters. Increase of sulfate concentration in freshwaters enhances accumulation of sulfide produced by sulfate-reducing bacteria. Actually, sulfide enrichments were observed in the sedimentary rocks from the terrestrial K-T and Permian-Triassic (P-T) boundary sections. The duration of the sulfide enrichments can be used for the discussion of the causes of the mass extinction events.
- 日本地球化学会の論文
- 2005-05-30
著者
関連論文
- 揮発性有機塩素化合物(CVOCs)原液の炭素安定同位体比(δ^C) : CVOCsによる地下水汚染の自然減衰プロセス解明に向けて
- 連続フロー型質量分析計による固体試料の炭素・硫黄同位体比分析 : 高精度分析のための改善点
- 多変量解析法を用いた北海道函館平野における深部地下水の供給源の推定
- 硫黄および炭素の安定同位体を用いた生物大量絶滅を引き起こした環境変動に関する研究
- 硫黄および炭素の安定同位体を用いた生物大量絶滅を引き起こした環境変動に関する研究(2004年度日本地球化学会奨励賞受賞記念論文)
- 多変量解析法を用いた北海道函館平野における深部地下水の供給源の推定
- 連続フロー型質量分析計による固体試料の炭素・硫黄同位体比分析 : 高精度分析のための改善点