Diagenesis of Carotenoid and Chlorophyll Pigments in Lake Sediments

本次调查的目的是确定 成岩作用控制类胡萝卜素的积累， 湖泊沉积物中的叶绿素色素 研究计划 包括现场数据收集和实验室实验。 现场方法包括测量母体的浓度 沉积物捕集器和沉积物中的色素及其衍生物 一组对比鲜明的湖泊的岩芯。 沉积物比较 捕获物和表层沉积物岩心， 对比湖泊 沉积物收集器材料和 表层沉积物将被用来评估 氧状态、沉积物混合、食虫动物活动和有机质 物质含量控制成岩速率。 实验室 实验涉及14C标记的颜料的生产， 藻类培养物，沉积物中标记色素的培养， 好氧和厌氧条件，以及测量速率和 沉积物细菌降解色素的途径（好氧和 厌氧的）和食虫的（摇蚊）。 方法将 包括通过HPLC分析色素和降解产物， 质谱法和使用210Pb测定沉积物 速率、沉积物混合和沉积物集中。 信息 湖泊沉积物中的色素成岩作用将有利于利用 沉积物色素分布图，以确定有机物来源， 藻类类型和初级生产力的变化，并评估 有机物循环在控制化学物质中的作用 湖泊的组成，都是至关重要的， 湖泊历史的古环境重建， 了解生物分子如何发展成地质分子。

The objective of this investigation is to determine the role of diagenesis in controlling the accumulation of carotenoid and chlorophyll pigments in lake sediments. The research plan includes both field data collection and laboratory experiments. The field approach involves measuring the concentrations of parent pigments and their derivatives in sediment traps and sediment cores from a group of contrasting lakes. Comparisons of sediment trap material and surface sediment cores from a group of contrasting lakes. Comparisons of sediment trap material and surface sediments will be used to evaluate the importance of oxygen status, sediment mixing, detritivore activity, and organic matter content in controlling diagenesis rates. Laboratory experiments involve production of 14C-labelled pigments using algal cultures, incubation of labelled pigments in sediments under aerobic and anaerobic conditions, and measurement of the rates and pathways of pigment degradation by sediment bacteria (aerobic and anaerobic) and a detritivore (chironomids). Methodology will include analysis of pigments and degradation products by HPLC and mass spectrometry and use of 210Pb to determine sedimentation rates, sediment mixing, and sediment focusing. Information on pigment diagenesis in lake sediments will facilitate using sediment pigment profiles to determine organic matter sources, changes in algal types and primary production, and to evaluate the role of organic matter cycling in controlling the chemical composition of lakes, all of primary importance to paleoenvironmental reconstruction of lake history and to understanding of how biomolecules develop into geomolecules.