Isotopengeochemische Charakterisierung kohlenwasserstoffbildender organischer Substanzen

Abstract

Abstract Within the framework of a larger research project on contributions of isotope investigations to natural gas and crude oil exploration, the following publication is a first part of research reports from the author's laboratory. The isotopic composition of carbon in fossil organic matter is primarily determined by the type of biological precursors. The main constituents forming organic matter in sediments are higher plants and microorganisms (algae, bacteria). These precursors contain a great number of organic compounds with corresponding isotope signatures. Hydrocarbons and lignin e.g., are enriched in carbon 13, while lipids in most cases are depleted. Semi-empirical calculations on a thermodynamic basis are used to precalculate isotopic compositions of components or single compounds, applying the so-called β-factor method. The results are compared with numerous data from references about isotopic compositions of higher plants, algae and plant components. Also environmental conditions of plant gr...