We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Reconstruction of peat-forming paleoenvironments within the Oligocene Bobov Doi Basin, SW Bulgaria: Insights from organic petrology.
- Authors
Zdravkov, Alexander; Bechtel, Achim; Groβ, Doris; Stojanović, Ksenija
- Abstract
Up to fourteen sub-bituminous coal beds are hosted within the Oligocene Bobov Doi Basin. Among them, six (numbered I to VI from base to top) are considered economically significant. In this study, ninety samples from five of the main seams (I-V) and a locally mined sub-seam (Ia) were characterized by maceral analysis and ash yield determination. The coal is composed of huminite (avg. 86.6 vol.%), liptinite (avg. 17.5 vol.%) and minor inertinite (avg: 1.5 vol.%). Maceral composition is dominated by gymnosperm-derived telohuminite (up to 72.0 vol.%) with resinite (up to 28.0 vol.%) and exsudatinite (up to 16.0 vol.%) cell infillings, embedded in attrinitic (avg. 21.0 vol.%) or densinitic (avg. 17.0 vol.%) groundmass. Most samples also contain abundant leaf-derived huminte (phyllo-huminite, up to 29.0 vol.%) in association with cutinite (up to 8.0 vol.%) and fluorinite (up to 5.0 voL%). Low to moderate ash yields (< 25 wt.% for most samples) coupled with low to moderate values of the maceral indices, namely TPI < 3 (for -80% of the samples) and GI < 3 (for >53% of the samples), and low values of the GWI < 1 (for 81% of the samples), denote organic matter deposition within an oligo- to mesotrophic topogenous mire with (ground)watertable beneath the peat surface. Reconstruction of paleoenvironmental settings based on maceral analysis (Fig. 1) argues for plant matter accumulation under marginal aquatic (seam Ia) and moderately wet- to dry-forested mires (seams I-V). Abundance of resinite and fluorinite-rich (phyllo-)huminite indicates development of conifer-dominated forests (likely deciduous gymnosperms), perhaps within a background of herbaceous plants and/or deciduous shrubs. The data is compatible with the previously reported preliminary organic geochemical data for part of the seams (Zdravkov et al., 2021).
- Subjects
OLIGOCENE Epoch; PETROLOGY; GYMNOSPERMS; HERBACEOUS plants; ORGANIC compounds
- Publication
Bulletin of the Geological Society of Greece, 2023, p52
- ISSN
0438-9557
- Publication type
Article