Molecular and Isotopic Fate of Alkenones and Alkenes During Early Diagenesis

9617892哈维，分子有机标记物的使用提供了关于世界海洋和沉积物中发生的各种输入和过程的宝贵信息。这些观测中往往缺少的是关于水柱和沉积物中的生物处理与最终保存在地质记录中的分子信号之间关系的定量信息。这些信息可能对长链烯酮特别重要，长链烷酮是几种海洋和沿海裸子植物藻类中存在的一组化合物，目前正被广泛用于详细描述海洋表面温度的近期和历史记录。最近在温度预测和同位素特征方面观察到了差异，但没有关于最初细胞生物合成后的烯酮和相关脂类的机制信息来证明成岩效应。这项工作将集中在海洋系统中烯酮、烯烃和烷基烯酸酯变化的两条主要途径：浮游动物放牧和微生物介导的过程。该项目将提供关于海洋水柱和表层沉积物中的烷基化合物和相关脂类的合成和去向的基本信息，并验证这些化合物或其降解产物提供对现在和过去海洋的海表面温度进行定量测量的潜力。***

9617892 Harvey The use of molecular organic markers has provided valuable information on a wide range of inputs and processes which occur in the worlds oceans and sediments. What is often absent from these observations, is quantitative information on the relationship of biological processing in the water column and sediments to the molecular signal which is ultimately preserved in the geological record. Such information may be particularly important for the long chain alkenones, a group of compounds present in several species of oceanic and coastal prymnesiophyte algae which are now being widely used to detail both recent and historical records of sea surface temperature. Recent disparities in temperature predictions and isotopic signature have been observed, yet no mechanistic information is available on the alkenones and related lipids after initial cellular biosynthesis to document diagenetic effects. This work will focus on the two major routes for the alteration of alkenones, alkenes and alkyl alkenoates in marine systems: zooplankton grazing and microbially mediated processes. The project will provide fundamental information on the synthesis and fate of the alkenones and related lipids in the marine water column and surface sediments and validate the potential for these compounds or their degradation products to provide a quantitative measure of sea surface temperature in present and past oceans. ***