Infrared spectrometric and gas chromatographic determination of the soluble organic matter from rock samples (oil shales)

Abstract

Oil shales of different types and ages from various locations were analysed to characterize their soluble organic matter. Among the techniques used, IR spectrometry and gas chromatography (GC) are of special interest. As far as their formation, age and depositional environment are concerned, the oil shale occurrences can be well distinguished by their IR spectra and the alkane distribution and the biomarker compounds can be identified by GC. The Botryococcus braunii alga is the dominant component of the original organic matter in the maar-type oil shales in Hungary. There are great similarities between Hungarian and Austrian oil shales of Triassic age. On the basis of the IR spectra and gas chromatograms, the differences found in the organic matter of oil shales of the same age and type coming from different countries can be explained by the type of the original organic matter sedimented (e.g., lagoon-type oil shales from Hungary and the Czech Republic). The differences in the site and appearances of absorption bands arising from aliphatic, aromatic and carbonyl stretching and deformation vibrations together with the presence or absence of the peaks of characteristic biomarker compounds in the gas chromatograms reflect the differences in the depositional conditions, the organic facies and the small paleoclimatic changes during the sedimentation of oil shales.