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

近古海洋沉积物陆源有机质定量表征研究的具体目标是：(i)改进和扩大识别陆地（和海洋）沉积有机质和确定其特征的方法，特别强调大分子成分；（ii）基于离散组分的耦合浓度-同位素组成测量的质量平衡计算，开发和完善混合模型；它更准确地描述了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离源距离的函数。这种方法建立在以前的研究基础上。将详细比较两种已建立的表征OC的方法，即CuO氧化和分析热解。对范围和局限性的并列定量评估将提供有用的定量地球化学信息，包括与选定的“端元”样品的TOC相关的主要成分的质量平衡。对代表性组分进行体积和化合物特定同位素测量将有助于这项任务。然后将对这些信息进行整理，并形成混合模式的基础，以描述陆地（和海洋）来源对沉积OC的贡献。这些模型的有效性将在存在丰富的补充地球化学信息的沉积环境（墨西哥湾、华盛顿边缘）的调查中得到评价。随后，这些模型将应用于目前对陆地有机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).