Origin, depositional environment and maturity of organic matter in Eocene coals from Tunisia

The aim of this study was to determine the origin and geological history of coals from Tunisia, using organic geochemical approach. Five coal samples were examined. After bitumen extraction and maltene fractionation, biomarkers in aliphatic fractions were analyzed using gas chromatography-mass spectrometry (GC-MS). The precursor organic matter (OM) was mostly represented by terrestrial vegetation with evident marine influence. Coals were formed under suboxic to oxidizing conditions. The maturity of OM corresponds to late diagenesis/early catagenesis, indicating subbituminous coal rank.