Aromatic biomarkers of sterane and hopane series in Upper Devonian oils and bitumoids of domanik deposits of the Timan-Pechora basin

We discussed results of study of aromatic hydrocarbons-biomarkers in the Upper Devonian oils and bitumens of the Domanik deposits of the Timan-Pechora basin. We showed that the distribution of triaromatic steroids of C26-C28 composition in the oils was slightly different from that in the bitumens, while the distribution of saturated steranes of C27-C29 composition for the oils and bitumens was quite close. TA(I)/TA(I+II) coefficient, calculated for triaromatic steroids, showed a significant increase with the degree of maturity of the organic matter of the Domanik rocks, and its values for the oils testified to their formation at the beginning of the oil window, which did not contradict the data from saturated hydrocarbons-biomarker. All the studied oils and bitumens were characterized by a close distribution of aromatic 8,14-secohopanes and benzohopanes.