2-Methylhopanoids as indicators of paleoproductivity in paleooceans during times of black shale deposition

2-甲基藿烷类化合物作为黑色页岩沉积时期古海洋古生产力的指标

• 批准号: 5435975
• 负责人: Professor Dr. Jürgen Rullkötter
• 金额: --
• 依托单位: Institut für Chemie und Biologie des Meeres (ICBM)
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5435975?language=en
• 关键词: Methylhopanoids; indicators; paleoproductivity; paleooceans; during

2-Methylhopanoids are biological markers of a significant number of cyanobacteria species. This project investigates if these fossil organic compounds are indicators of high primary productivity in the paleoocean involving nitrate limitation and subsequent nitrogen fixation. Cretaceous black shales from Shatsky Rise in the central Pacific Ocean drilled during ODP Leg 198 are the test case for this study. 2-Methylhopanoid profiles across these black shales are contrasted to those in over- and underlying sedimentary rocks. In addition, the distribution patterns across the black shale are studied for steady or oscillating changes of paleoproductivity. A novel approach is the combined analysis of free 2-methylhopanoids in the extractable bitumen fraction and bound analogs in the insoluble macromolecular organic matter. For comparison, sapropels from the eastern Mediterranean Sea (ODP Leg 160) representing a significantly younger age and a different paleoceanographic setting are investigated in the same way. Cretaceous black shales from the North and South Atlantic Ocean are possible further targets for comparison. Finally, cultured cyanobacteria are investigated for their 2-methylhopanoid content to extend the basis for interpretation in fossil organic matter.

2-甲基类动物是大量蓝细菌物种的生物学标志物。该项目研究了这些化石有机化合物是否是涉及硝酸盐限制和随后的氮固定的古洋中高级生产率的指标。在ODP腿198期间，来自Shatsky的白垩纪黑色页岩是本研究的测试案例。这些黑色页岩中的2-甲基类动物轮廓与过度和潜在的沉积岩中的曲线形成鲜明对比。另外，研究了黑色页岩上的分布模式，以稳定或振荡古生物生产力的变化。一种新颖的方法是对可提取沥青馏分中的游离2-甲基类动物的组合分析以及不溶性的大分子有机物中的结合类似物。为了进行比较，以相同的方式研究了来自地中海东部海洋（ODP腿160）的腐肉（ODP腿160）。来自南大西洋和南大西洋的白垩纪黑色页岩是比较的进一步目标。最后，研究了培养的蓝细菌的2-甲基类球含量，以扩展化石有机物中解释的基础。