Environmental changes from greenhouse earth to icehouse earth through a study of chalk/black shale sequence

通过白垩/黑色页岩序列研究从温室地球到冰库地球的环境变化

• 批准号: 10304039
• 负责人: TAIRA Asahiko
• 金额: $ 12.93万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10304039/
• 关键词: Cretaceous; Chalk; Black Shale; Anoxic Event; Cyanobacteria; Carbon Isotope; Sulfur Isotope; Blue Tide; チヨーク

A chalk/black shale sequence exposed in the Appenine Mis. in Italy was investigated in order to reveal the basic marine environmental setting in the Cretaceous warm period. Cenomanian/Turonian black shale (Bonalleli horizon) showed the following characteristics.1. The source of organic matter is bacterial origin (Cyanobacteria and photosynthesic bacteria).2. Large excursion of sulfur isotope suggests strong ocean stratification with anoxic bottom water. About 30% of total sulfur from the global ocean was fixed as pyrite. The ocean surface had to be highly oligotrophic.3. Occasional instability of stratified ocean and upwelling caused events of nutrient supply to the surface that caused radiolarian blooming.

在亚平宁盆地暴露的白垩/黑色页岩序列。以揭示白垩纪暖期的基本海洋环境背景。Cenomanian/Turonian黑色页岩（Bonalleli层）具有以下特征：有机质的来源主要是细菌源（蓝藻和光合细菌）。硫同位素的大偏移表明海底缺氧形成强烈的海洋分层。全球海洋中约30%的总硫被固定为黄铁矿。海洋表面必须是高度寡养的。分层海洋的偶尔不稳定和上升流引起的营养供给事件导致放射虫大量繁殖。

项目成果

Tamura Y.: "Primary arc basalts from Daisen Volcano,Japan:equilibrium crystal fractionation versus disequilibrium"Journal of Petrology. 41. 431-448 (1999)

Tamura Y.：“日本大山火山的原生弧玄武岩：平衡晶体分馏与不平衡”岩石学杂志。

村山雅史: "古海洋学における放射性炭素年代測定法とその問題点"月刊地球. 22. 645-650 (2000)

Masashi Murayama：“放射性碳测年及其在古海洋学中的问题”，地球月刊 22. 645-650 (2000)。

Sato,T.: "Quatemary geomagnetic field intensity: Constant periodicity or variable period?" Geophys.Res.Lett.25. 2221-2224 (1998)

Sato,T.：“第四纪地磁场强度：恒定周期还是可变周期？”

Asahiko TAIRA: "Nature and growth rate of the Northern Izu-Bonin (Ogasawara) arc crust and their implications for continental crust formation" The Island Arc. 7. 395-407 (1998)

Asahiko TAIRA：“北伊豆-小笠原（小笠原）弧地壳的性质和生长速度及其对大陆地壳形成的影响”岛弧。

大河内直彦: "バイオマーカーによる古海洋環境の復元・太平洋における深海底堆積物を例として-" 地学雑誌. 197. 40-53 (1998)

Naohiko Okochi：“利用生物标记重建古海洋环境：以太平洋深海海底沉积物为例”Geogaku Zasshi，197. 40-53 (1998)。