OIL SHALE, cilt.23, sa.4, ss.297-312, 2006 (SCI-Expanded)
A Middle Miocene playa-lake sedimentary sequence containing oil shales and trona is divided into the Gokpinar (the lower oil shale unit) and the Terzioglu (the upper oil shale unit) Members in the Gurun Basin in eastern Turkey. Thermal decomposition of Gurun oil shales was studied by thermo-gravimetry (TGA), differential thermal analysis (DTA), and Rock Eval pyrolysis. Na2O content of oil shales reaches 0.2%, SiO2 content reaches 31.5%, and CaO content ranges from 29.8 to 52.7%. Content of Sr, Cu, Zn, Ba and Zr (ppm) exceeds that of other trace elements. In the lower oil shale unit, TOC reaches 9.03 wt%, whereas in the upper oil shale unit, the maximum TOC value is 1.54 wt%, generally being even lower. Oil shale contains mainly calcite, aragonite and montmorillonite minerals. DTA curves of oil shale samples show that exothermic peaks are compatible with TOC values. Weight loss is compatible with chemical properties, DTA results and TGA curves of oil shale. Organic geochemical analyses indicate that Gurun oil shale contains sufficient amounts of kerogen of good quality to generate both oil and gas upon pyrolysis.