eesti teaduste
akadeemia kirjastus
SINCE 1984
Oil Shale cover
Oil Shale
ISSN 1736-7492 (Electronic)
ISSN 0208-189X (Print)
Impact Factor (2020): 0.934


Full article in PDF format | doi: 10.3176/oil.2014.4.02



In the Eskişehir Basin, western Turkey, oil shale occurs in alterna­tion with claystone, siltstone, conglomerate and coal (lignite) seams in lacustrine deposits of Early-Middle Miocene age. The thickness of oil shale seams drilled during the study varies between 20 and 30 m. Organic geo­chemical features of the shale were evaluated using TOC, pyrolysis, GC and GC-MS analyses.
   The Eskişehir oil shale is characterized by very high TOC contents (6.32–37.15 wt%), Hydrogen Index (HI = 392–777 mg HC/g TOC), Potential Yield (PY = 35.50–159.32 mg HC/g rock) and very low Oxygen Index (OI = 13–92 mg CO2/g TOC) values. Organic matter in the studied oil shale is of Type II kerogen and shows S2/S3 ratio values between 5.49 and 56.79 and low Tmax (421–435 °C ) and PI (0.01–0.05) values.
   Low Pr/Ph ratio of oil shale (0.17–0.96) is indicative of anoxic conditions. Dominant steranes are either C27 or C28. Normal steranes are more abundant than iso- and diasteranes and diasterane abundances as well as 20S/(20S + 20R) and bb/(bb + aa) sterane ratios are low.   While oil shale samples in general have low tricyclic terpane (C19–C29) abundance, their C30 (R + S) tricyclic terpane content is high. For all the oil shale samples studied C29/C30 hopane, C31R homohopane/hopane and moretane/hopane ratios are high and Ts/(Ts + Tm) and C29Ts/(C29Ts + C29H) ratios are low. 22S homohopanes are recorded in lower quantities in comparison to 22R epimers and the 22S/(22S + 22R) homohopane ratio is low.


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