摘要：Aromatic hydrocarbons are present in thefossil wood samples in relatively smallamounts. In almost all of the tested samplesthe dominating aromatic hydrocarbonis perylene and its methyl and dimethyl derivatives.The most important biomarkerspresent in the aromatic fraction are dehydroabietane,siomonellite and retene, compoundscharacteristic for conifers. The distributionof discussed compounds is highlyvariable due to such early diagenetic processesaffecting the wood as oxidation andthe activity of microorganisms. MPI1 parametervalues (methylphenanthrene index)for the majority of the samples are in therange of 0.1 to 0.5, which results in the highlyvariable values of Rc (converted value ofvitrinite reflectance) ranging from 0.45 to0.70%. Such values suggest that MPI1 parameteris not useful as maturity parameter incase of Middle Jurassic ore-bearing clays,even if measured strictly on terrestrial organicmatter (OM). As a result of weatheringprocesses (oxidation) the distribution ofaromatic hydrocarbons changes. In the oxidizedsamples the amount of aromatic hydrocarbons,both polycyclic as well as aromaticbiomarkers decreases.
