Reconstruction of the Water Column Structure of Jurassic and Cretaceous Epeiric Seas: Biomarkers and their Carbon Isotopic Composition

9614769凯尼格建议的目标是利用生物标志物及其同位素组成重建侏罗纪和白垩纪浅海的水柱结构。更具体地说，我们的工作将集中在重建水柱化学及其在两个沉积物地层沉积过程中的演变，这两个沉积物地层是牛津粘土(英国中卡洛维亚)和格林霍恩地层(西部内海，塞诺马诺-图罗尼亚，美国)。我们将利用这些信息来了解陆表海水柱分层开始时的古海洋条件、生物相分布和有机质积累。这些结果将被用来检验生物相与底栖氧水平的关系。这些结果将被用来进一步约束现有的古海洋环流模型。第一个目标是确定间歇性缺氧事件的地理范围，这些事件以牛津下粘土富含有机质的化石滞后统计物质的积累为特征。为了实现这一目标，将分析来自苏格兰、英格兰中部和南部、法国、德国、瑞士和波兰的具有明确生物相的中卡洛夫沉积，以寻找其自由、硫结合和乙醚结合的碳氢化合物生物标志物。第二个目标是利用格林霍恩组热不成熟样品的分子化石记录，重建西海内海在Cenomian和Turonian时期的水柱结构。三个部分将详细研究它们的自由、硫结合和乙醚结合的分子化石。这一分析程序将使我们能够瞄准对水柱结构具有诊断作用的分子。这将导致制定一种有效的分析方案，使其能够对大量样品进行分析，以精确限制大片地理区域的水柱结构和化学成分。第三个目标将是在地理上扩大塞诺马尼亚和图罗尼亚时期西部内海航道的水柱重建。我们将使用这些结果来约束为西部内海建立的古海洋环流的计算机模型。与西欧中卡洛夫期的结果进行比较，将加深我们对陆表海古海洋环流的理解。在文献资料和水柱重建的基础上，提出了西欧中卡洛纪的古海洋环流模式。

9614769 Kenig The goal of the proposal is to reconstruct the water-column structure of a Jurassic and a Cretaceous epeiric sea using biomarkers and their isotopic composition. More specifically, our efforts will concentrate on the reconstruction of the water-column chemistry, and its evolution during the deposition of two sediment formations, the Oxford Clay (Middle Callovian, UK and the Greenhorn Formation (Western Interior Seaway, Cenomano-Turonian, USA). We will use this information to understand paleo-oceanographic conditions at the onset of water column stratification, biofacies distribution, and organic matter accumulation in epeiric seas. These results will be used to test the relationship between biofacies and benthic oxygen level. These results will be used to further constrain existing paleo-oceanographic circulation models. The first objective is to determine the geographic extent of intermittent anoxic events that characterized the accumulation of the organic mater-rich fossil-laggerstatten of the Lower Oxford Clay. To achieve this, Middle Callovian sediments with well defined biofacies from Scotland, Central and Southern England, France, Germany, Switzerland and Poland will be analyzed for their free, sulphur-bound, and ether-bound hydrocarbon biomarkers. The second objective is to use the molecular fossil record of thermally immature samples from the Greenhorn formation to reconstruct the water-column structure of the Western Interior Seaway during the Cenomanian and Turonian. Three sections will be investigated in detail for their free, sulphur-bound, and ether-bound molecular fossils. This analytical procedure will allow us to target the molecules that are diagnostic for the water-column structure. It will result in the development of an efficient analytical scheme allowing analysis of the vast number of samples necessary for precise constraint of the water-column structure and chemistry of a large geographical area. The third objective will be to geographicall y extend the water-column reconstruction of the Western Interior Seaway during the Cenomanian and Turonian. We will use these results to constrain the computer models of paleo-oceanographic circulation constructed for the Western Interior Seaway. Comparison of the results obtained from the Middle-Callovian of Western Europe will enhance our understanding of paleo-oceanographic circulation in epeiric seas. Based on literature data and our water-column reconstruction, a model of the paleo-oceanographic circulation for the Middle Callovian of Western Europe will be proposed.