Akademik Veri Yönetim Sistemi
INTERNATIONAL JOURNAL OF COAL GEOLOGY, cilt.265, ss.1-62, 2023 (SCI-Expanded)
The Şarkikaraağaç coalfield is located in the north-western part of the Lake Beyşehir Basin, which is the most significant graben area in the eastern flank of Isparta Angle, and hosts a 300-Mt coal resource. This study focuses on the first palaeoenvironmental and palaeoclimatic reconstruction of Pliocene and early Pleistocene coal-bearing sequences cored in the two coal exploration wells (SK-1 and SK-2) using coal petrography, mineralogy, faunal (ostracod and mollusk), and floral (palynology and diatom) data from four coal seams (from bottom to top: B, A, X-1, and X-0) with the variable total thickness (1 to 7 m). According to the palynological data, warm and humid climate conditions prevailed during the early Pliocene, and the precursor peats of seams A and B were mainly accumulated under limno-telmatic conditions, with high contributions of herbaceous peat-forming plants. Nevertheless, the co-occurrence of syngenetic carbonate minerals and framboidal pyrites along with calcareous fossil and diatom remains implies neutral to weakly alkaline conditions within palaeomires of these seams. Furthermore, ostracod and gastropod fauna from these seams might imply nutrient-rich shallow water conditions and spring support (e.g., karstic aquifer) into palaeomires. Thus, algal activity within the palaeomires was presumably high, and freshwater algae and diatoms were commonly identified in these seams.With the development of increased uplift ratio of central Taurides and climatic changes towards to late stages of Pliocene and particularly early Pleistocene, the common peat-forming plants within palaeomires and vegetation in the surrounding areas were changed. The increased precipitation caused an elevation of water levels in the study area; hence, the precursor peats of the seam X-1 were accumulated under wet forest mire conditions. This increase also explains the existence of ostracod and mollusk fauna related to river and spring support underlying sequences of the seam X-1. With the ceasing of accumulation of peat of the seam X-1, the climate became drier, and very shallow water conditions have been common. The development of spring support and relatively high precipitation in a short period of time allowed for final peat accumulation (seam X-0) during the early Pleistocene. Nevertheless, this period was followed by the development of relatively colder conditions in the study area, and cold small water conditions were developed during the end of the early Pleistocene. Furthermore, microthermic vegetation was common in the vicinity of the palaeomires during the early Pleistocene. Overall, the peat accumulation and water level of lakes in the study area seem to be controlled by climatic oscillations and uplift of margins of the Lake Beyşehir Basin during the Pliocene to early Pleistocene.