Organic geochemical characteristics of the bituminous Eocene units in the Çorum–Suluova Basin, Central Anatolia, Turkey

Abstract

In the Çorum–Suluova Basin (central Anatolia) the Eocene Çeltek and Armutlu formations consist of conglomerate, sandstone, siltstone, marl, mudstone, shale, limestone, clayey limestone, bituminous shale and coal. Total organic carbon (TOC) values in the Çeltek Formation range between 0.1 and 8%. Rock-Eval analyses on core samples with the highest TOC values give hydrogen index (HI) values from 45–846 mgHC g −1 TOC and oxygen index (OI) values from 9–64 mgCO 2 g −1 TOC. The organic matter can be classified as Type I and Type II kerogen on the modified van Krevelen diagram. T max values vary between 428° and 440°C, with an average of 436°C, indicating the catagenesis stage. Based on the microscopic studies, organic matter is composed of predominantly autochthonous algal and amorphous material, with a minor contribution of terrestrial material. The Çeltek Formation can be regarded as a source rock for hydrocarbons. The TOC content of the Armutlu Formation is poor. Samples consist of terrestrial and reworked organic matter. Vitrinite reflectance values are between 0.27% and 0.43%, with an average of 0.34%. T max values are between 433°C and 436°C, with an average of 435°C. The HI value is between 29 mgHC g −1 TOC and 39 mgHC g −1 TOC. Considering the data, the Armutlu Formation cannot be the source rock.

The Environmentally Significant Element Contents of Eocene Coals in North Anatolia, Turkey

“…Coals in the North Anatolia region are found in Eocene units. A number of geological works are conducted on these coals and surrounding areas (Özen, 1975;Gümüşsu, 1980;Özdemir and Bekmezci, 1983;Erdem and Akalın, 1983;Öz and Göçmen, 1988;Karayigit et al, 1996aKarayigit et al, , 1996bAtalay, 2001;Altunsoy et al, 2001;Koç and Türkmen, 2002;Altunsoy et al, 2003).…”

Relationships between coal-quality and organic-geochemical parameters: A case study of the Hafik coal deposits (Sivas Basin, Turkey)

“…This technique has been used on our coal samples and has been shown by other workers to be useful in organic-petrographic explanations (Teichmüller and Durand, 1983;Fowler et al, 1991;Altunsoy et al, 2004;Korkmaz and Kara Gülbay, 2007).…”

Mineral composition and organic geochemistry of the Lower Cretaceous Xiagou Formation source rock from the Qingxi Sag, Jiuquan Basin, Northwest China

“…10). High C 19 -C 20 -C 21 tricyclic terpanes indicate that organic matter derived from a terrestrial origin (Ozcelik and Altunsoy 2005), high C 23 tricyclic terpane indicates a high contribution of marine matter (Ourisson et al 1982), and C 24 tetracyclic terpane was mainly sourced from terrestrial OM input (Philp and Gilbert 1986). Low C 24 tetracyclic terpane/C 23 tricyclic terpane reflects reducing conditions (Waples and Machihara 1991).…”