Assessing the geochemical signatures of abiogenically dominated methane sources

评估非生物成因甲烷来源的地球化学特征

• 批准号: 76326059
• 负责人: Professor Dr. Jens Fiebig
• 金额: --
• 依托单位: Institute of Earth Surface Dynamics (IDYST)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/76326059?language=en
• 关键词: Assessing; geochemical; signatures; abiogenically; dominated

Methane (CH4) and the higher hydrocarbons are of particular interest for society. The majority of naturally occurring hydrocarbons is assumed to derive from biogenic (thermogenic and microbial) sources. Unambiguous evidence for abiogenic reduction of CO2 to hydrocarbons within the Earth s crust has been lacking. Recently, we demonstrated the occurrence of abiogenic production of CH4 in three subduction-related bi-phase-hydrothermal systems of the Mediterranean region. These localities offer a great opportunity to study the abiogenic signature of these hydrocarbons in terms of the classical chemical and isotopic parameters, which are commonly used to distinguish thermogenic from microbial sources. Comparison of theoretical and empirical data with measured data will enable a) an estimate of the extent that biogenic sources contribute to overall hydrocarbon production in abiogenically dominated systems, and b) an assessment of the extent that abiogenically dominated sources might have been erroneously classified as biogenic. In search of new indicators for abiogenically dominated sources, we will investigate the factors that exert control on the occurrence of aromatic and unsaturated hydrocarbons in these volcanic-hydrothermal systems.

甲烷 (CH4) 和高级碳氢化合物受到社会的特别关注。大多数天然存在的碳氢化合物被认为源自生物（生热和微生物）来源。地壳内二氧化碳非生物还原为碳氢化合物的明确证据一直缺乏。最近，我们证明了地中海地区三个与俯冲相关的双相热液系统中CH4的非生物产生。这些地点提供了一个很好的机会，可以根据经典化学和同位素参数来研究这些碳氢化合物的非生物特征，这些参数通常用于区分生热源和微生物源。将理论和经验数据与测量数据进行比较将能够a）估计生物源对非生物主导系统中总体碳氢化合物生产的贡献程度，以及b）评估非生物主导源可能被错误分类为生物源的程度。为了寻找以生物为主的来源的新指标，我们将研究控制这些火山热液系统中芳香烃和不饱和烃出现的因素。