Organic Matter Isotopic and Molecular Stratigraphy Across K/T Boundaries

跨 K/T 边界的有机物同位素和分子地层学

• 批准号: 9117839
• 负责人: Philip Meyers
• 金额: $ 10万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-07-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9117839&HistoricalAwards=false
• 关键词: Organic; Matter; Isotopic; Molecular; Stratigraphy

The Cretaceous/Tertiary boundary is marked by a particularly extensive change in the fossil record. A consequence of this major biotic perturbation would be a change in the composition and the amount of organic matter contributed to depositing sediments. The project will investigate the nature of the organic matter contents of sediments deposited during late Maastrichtian times, at the K/T boundary itself, and during early Danian times. Analyses will include elemental, isotopic, and molecular identifiers of the sources and of the preservation of organic matter components. Two K/T sections, Brazos (Texas) and Raton Basin (New Mexico), have been studied by many investigators. Microfossil, palynological, and other stratigraphic information exist from both locations, which will be helpful in interpreting the geochemical data in terms of paleoenvironmental changes. Closely spaced samples from several sites at these locations will be the subject of this project. The investigation will extend to "background" sediments deposited well before and well after the actual K/T boundary in order to determine the extent of natural variability. Furthermore, geochemical information has suggested a relationship between iridium anomalies at the boundary and microbial activity, which can be tested by searching for biomarker molecules indicative of microbial residues in the organic matter record.

白垩纪/第三纪边界的特点是化石记录发生了特别广泛的变化。 这种主要生物扰动的结果将是导致沉积物沉积的有机物的成分和数量发生变化。 该项目将调查马斯特里赫特阶晚期、K/T 边界本身以及达尼阶早期沉积物的有机质含量性质。 分析将包括有机物成分来源和保存的元素、同位素和分子标识符。 许多研究人员已经研究了两个 K/T 剖面：布拉索斯（德克萨斯州）和拉顿盆地（新墨西哥州）。 这两个地点都存在微化石、孢粉学和其他地层信息，这将有助于解释古环境变化方面的地球化学数据。 来自这些地点的几个地点的紧密间隔的样本将是该项目的主题。 该调查将扩展到实际 K/T 边界之前和之后沉积的“背景”沉积物，以确定自然变化的程度。 此外，地球化学信息表明边界处的铱异常与微生物活动之间存在关系，可以通过在有机物记录中搜索指示微生物残留物的生物标记分子来测试这种关系。