Total organic carbon content, type, and hydrocarbon generati̇on potential of early miocene-age ömerler (Tunçbilek-Kütahya) lignites

In the thesis, the organic geochemical properties, carbonization degree, depositional environment, and paleoclimatic conditions of Miocene aged coals belonging to the İğdekuzu underground mine in Ömerler (Tunçbilek-Kütahya) area were evaluated using approximate analysis, Pyrolysis/TOC and gas chromatography (GC) analyses. The upper calorific values of the coals belonging to the İğdekuzu underground mine vary between 6027 - 6360 (average 6194) and the lower calorific values range between 5798 - 6117 (average 5958) on an air-dry basis. The total organic carbon (TOC) values of the bottom, middle, and top sections of the coals vary between 61.49% - 87.55%, 79.55% - 90.98% and 57.93% - 97.14%, respectively, and it has a very good source rock potential for oil. The hydrogen index (HI) values of bottom, middle, and top coals vary between 197 – 274 mgHK/gTOK, 176 – 215 mgHK/gTOK and 170 – 206 mgHK/gTOK, respectively. All samples contain very low oxygen index (OI), S3 and very high S2 values and generally contain Type II and Type II-III kerogen. The maximum temperature (Tmax ) values of the bottom coals vary between 435 – 441 °C, the Tmax values of the middle part vary between 439 – 443 °C, and the Tmax values of the upper part vary between 436 – 442 °C, indicating thermal maturity. In the GC analysis of the samples, the unimodal distribution, in which long-chain n-alkanes are dominant over short-chain n-alkanes, draws attention. Pr/Ph ratios of the upper part, middle, and bottom samples have been determined as 2.67, 4.71, and 2.41, respectively, Carbon preference index (CPI) values have been determined as 1.28, 1.47, and 1.44, respectively, and Terrigenous/aquatic organic matter ratio (TAR) values have been determined as 36.34, 16.80, and 8.62, respectively. The coals examined were deposited in a paralic basin, which is an oxic-suboxic environment, containing predominantly terrestrial organic matter, in warm and humid climatic conditions, and have not yet reached the stage of producing hydrocarbons. Keywords: Depositional environment, Gas chromatography, Coal, Hydrocarbon, Miocene, Ömerler (Tunçbilek), Paleo-climate, TOC/Priolis