| Abstract: | Model investigations, carried out as laboratory coalification reactions with humous and sapropelitic sediments of different maturation degree, showed that conclusions can be drawn about the character of the parent rock of a natural gas using data of the chemical and isotopic composition of the organic substance in sediments and its coalification products. Several examples demonstrate, that the following parameters have proved as suitable fades- and in part as maturity criteria: CH4/Σ HKW; C2H6/CH4, i-/n-C4H10, 13C-abundance of organic substance, 13C-abundance of methane. For a complex interpretation all results obtained from coalification experiments over some years were stored in a data file. By means of cluster analysis all samples were classified in groups corresponding to their characteristics represented by the above mentioned five criteria. Four clusters resulted depending on maceral composition of the tested organic sediments. The differentiating criteria of these clusters are discussed. |
