Molekulare Fossilien: Schlüssel zum Ursprung diagenetischer Karbonatkonkretionen

分子化石：成岩碳酸盐结核起源的关键

• 批准号: 389337055
• 负责人: Professor Dr. Volker Thiel
• 金额: --
• 依托单位: Institut für Mikrobiologie und Genetik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/389337055?language=en
• 关键词: Molekulare; Fossilien; Schl; ssel; zum

Diagenetic carbonate concretions commonly form during shallow burial via localized lithification of soft sediment and have long been recognized as a source of exceptionally preserved fossils. While concretions are common in many ancient sediments, modern equivalents are very rare and our understanding of the complex biogeochemical processes underlying their formation is incomplete. In this project the organic matter enclosed in ancient concretions is studied with organic geochemical techniques to provide further clues to the formation of these precipitates and test their significance as containers of exceptionally preserved molecular fossils. It is proposed that lipid biomarkers and kerogen locked in concretions may represent a "snapshot" of the original sedimentary OM, plus the early microbial processes as they once occurred in the freshly deposited sediment. A particular focus is placed on testing the role of Ca- and or Mg-salts of carboxylic acids (particularly fatty acids, "adipocere"), and their anaerobic degradation products as raw materials for the formation of carbonate concretions. For this purpose, ancient (Early Jurassic) carbonate concretions from Buttenheim (Bavaria) and Hondelage (Lower Saxony) will be studied in relation to their immediate host rocks using extract based (GC-MS, IRM-GC-MS) and pyrolysis techniques (Hypy; Py-GC-MS).

成岩成岩碳酸盐结构在浅埋葬过程中通常通过柔软的沉积物的局部化形式形成，并且长期以来一直被公认为是特殊保存的化石的来源。尽管具体在许多古老的沉积物中很常见，但现代等效物非常罕见，我们对它们形成的复杂生物地球化学过程的理解是不完整的。在该项目中，用有机地球化学技术研究了古代混凝土中包含的有机物，以提供进一步的线索，以形成这些沉淀物，并测试其作为特殊保存的分子化石容器的重要性。有人提出，将脂质生物标志物和锁定在混凝土中的动脉粥样硬化可能代表原始沉积物OM的“快照”，以及曾经在新鲜沉积的沉积物中发生的早期微生物过程。特定的重点是测试羧酸（尤其是脂肪酸，“脂肪”）的Ca-和或mg - 盐的作用，以及它们的厌氧降解产物作为形成碳酸盐混凝土的原材料。为此，将研究使用基于提取物（GC-MS，IRM-GC-MS）和Pyylolysisice（Hypy; hypy; py-gc-ms）的直接宿主岩石（hyptenheim）和Hondage（Bavaria）和Hondage（Lower Saxony）的古代（早期侏罗纪）碳酸盐结构。