Organic geochemical properties of miocene aged Himmetoğlu coals

In this study, the organic geochemical properties of the coals in Himmetoğlu region of Göynük in the southwest of Bolu Province were examined. The total amount of organic carbon (TOC) contained in Himmetoğlu coal and clayed coals varies between 17.42-55.59%. The type of organic matter, maturity, hydrocarbon potential and conditions of the depositional environment of the coals which have generally low Hİ (average 134 mgHC/gTOK) and high Oİ (average 78 mgCO2/gTOK) were examined. It has been determined that the kerogen type is predominantly Type III and lesser Type II. Tmax in the range of 424-440°C and production index value between 0.01-0.03 obtained from pyrolysis and very high CPI values over 1 and high peak concentrations in the biomarker region obtained from GC analyzes indicate that the organic matter of the coals do not mature. According to TAR, ACL, Paq, Pwax, C23/C25, C23/C29 values, in the first 8.5 meter part of the section, HK-4, HK-11, HK-16 samples were deposited in a swamp environment where dry and cold climatic conditions prevail. In the part of the section after 8.5 meters, it was determined that the water level changed over time, rising and falling again. It was interpreted that the climate was rainy in the period when the GH-12 sample which has sapropelic character was taken and therefore the environment was submerged. Pr/Ph ratios for HK-4, HK-11, GH-12 samples are 0.90, 0.00, and 0.58 respectively, indicating that the depositional environment is anoxic.