Isotopic signatures of organic matter in the Upper Miocene–Pliocene Elbistan coal seam (Turkey): Insights from δ13C and δ15N variability
Year: 2025
Type: article
Abstract: This study examines the stable carbon (δ 13 C) and nitrogen (δ 15 N) isotope compositions of coal samples from the Upper Miocene–Pliocene (Neogene) Elbistan Basin, Turkey, to constrain the sources of organic matter and the depositional conditions of peat formation. A vertical sequence of samples collected from the Kışlaköy open-pit mine was analysed for total carbon and nitrogen contents, C/N ratios, and δ 13 C–δ 15 N values. The δ 13 C values range from −28.09 ‰ to −16.99 ‰, while δ 15 N values vary between 1.97 ‰ and 4.99 ‰. The carbon isotope data indicate a predominantly C 3 -type plant origin for the organic matter, with minor C 4 contributions inferred from samples exhibiting enriched δ 13 C signatures. Although some δ 13 C enrichment may partly reflect microbial alteration of organic matter, the overall values remain consistent with a dominant C 3 vegetation signal. Elevated δ 15 N values suggest fluctuating redox conditions and microbial nitrogen cycling during peat accumulation. In comparison with other Turkish lignite basins and global coal deposits, the Elbistan samples display a broader isotopic range, reflecting a more complex paleoenvironmental evolution. The data suggest that the coal beds formed mainly in freshwater mire settings, where fluctuating water tables, variable redox conditions, and occasional inputs from C 4 plants influenced peat accumulation. These results provide new insights into the paleobotanical and geochemical history of the basin and demonstrate the value of stable isotope analysis for reconstructing depositional environments in coal-bearing successions.
Source: Organic Geochemistry
Institutions: Fırat University, Maden Tetkik ve Arama Genel Müdürlüğü
Language: English
Topic: Coal and Its By-products
Subfield: Geochemistry and Petrology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: hybrid
Estimated APC paid: $3,270
Award: G4001492737
OpenAlex ID: W4415601228