Thermal methods implementation in analysis of fine-grained rocks containing organic matter

Abstract

The thermal methods, including TG and DSC techniques, were implemented to determine the composition of the fine-grained rocks with dispersed organic matter. The analyses were carried out in inert and oxidising atmosphere. The analysed samples represented Palaeozoic siltstones, shales, claystones and mudstones from Baltic Basin, Lublin Basin and Upper Silesian Coal Basin (Poland). There was detected the presence of some minerals as: clay minerals, muscovite, quartz, calcite, dolomite and pyrite. A comparison of the reactions occurring in an oxidising and inert atmosphere can give a solution to the problem of some effects overlapping, such as distinguishing pyrite decomposition from organic matter combustion. The analysis of DSC curves of heated rocks under oxidative atmosphere allows to determine the temperature regions of the organic matter combustion and to conclude on its maturity level. There was also found a strong correlation between the mass loss resulted from organic matter combustion, and the mass loss as a result of pyrolysis.