Quantitative Characterization of Terrestrially-derived Organic Matter in Recent and Ancient Marine Sediments

现代和古代海洋沉积物中陆源有机质的定量表征本研究的具体目标是：(I)改进和扩展识别和表征陆源(和海洋)沉积有机质的方法，特别强调大分子组分；(2)根据对离散组分进行浓度-同位素组成耦合测量的质量平衡计算，开发和改进混合模型，更准确地描述河流系统对陆架或盆地沉积物的贡献，并将这些贡献描绘为距源头的距离的函数。这一方法建立在之前的研究基础上。对两种已建立的表征有机碳的方法进行了详细的比较，即CuO氧化和分析热解。对范围和限度的并排定量评估将提供有用的定量地球化学信息，包括选定的“终端成员”样品的主要成分与总有机碳的质量平衡。这项任务将通过对代表性成分进行大量和化合物的特定同位素测量而得到便利。然后，这些信息将被整理，并将形成混合模型的基础，以描述陆地(和海洋)来源对沉积有机碳的贡献。这些模型的有效性将在存在丰富补充地球化学信息的沉积环境调查中得到评价(墨西哥湾、华盛顿边缘)。随后，这些模型将应用于目前对陆地有机物质影响的了解较为有限的关键环境(黑海、亚马逊陆架)。

Quantitative Characterization of Terrestrially-derived Organic Matter in Recent and Ancient Marine Sediments Specific Objectives of this research are: (i) To improve and expand methods to recognize and characterize terrestrial (and marine) sedimentary organic matter, with special emphasis placed upon macromolecular components; (ii) to develop and refine mixing models, based on mass balance calculations using coupled concentration-isotope composition measurements on discrete components, which more accurately describe the contributions from river systems to shelf or basin sediments and to delineate these contributions as a function of distance from source. The approach builds upon previous studies. A detailed comparison of two established methods for characterizing OC, namely CuO oxidation and analytical pyrolysis will be performed. A side-by-side quantitative evaluation of the scope and limitations will provide useful quantitative geochemical information including a mass balance of the major constituents with respect to TOC for selected "end-member" samples. This task will be facilitated by bulk and compound specific isotopic measurements on representative components. This information will then be collated and will form the basis for mixing models developed to describe contributions from terrestrial (and marine) sources to sedimentary OC. The validity of these models will be appraised in investigations of sedimentary environments for which abundant supplementary geochemical information exists (Gulf of Mexico, Washington margin). Subsequently the models will be applied to key environments in which present understanding of terrestrial organic matter influences is more limited (Black Sea, Amazon shelf).