Sedimentology, cyclostratigraphy, sequence stratigraphy and geochemistry of the middle eocene lacustrine-marine oil-shales transition, Mudurnu Göynük basin, NW Anatolia, Turkey

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2019
Afridi, Bakht Zamir
Continuous studied successions of the Middle Eocene, Mudurnu-Göynük basin, in the NW Anatolia indicate a transition from marine-influence lacustrine to marine environment due to the relative rise in sea-level, which was separated by barrier deposits. Different lithofacies are identified in the studied sections, including limestone, marl, oil-shale, calcareous sandstone, conglomeratic and bio-calcirudite. Number of fossil assemblages are recorded including ostracods, charophyte gyrogonites, gastropods, bivalve and b enthic foraminifera, rare fish-teeth-scale, echinoderms, algal filamentous and plant fragments. The recorded ostracod interprets Oligo-Mesohaline lacustrine environment, which is overlain by marine environment. Based on the detailed facies analysis, the depositional environment is characterized as relatively marginal to deep lacustrine- marine deposits, floodplain to paralic-marine deposits, from south to north. The lacustrine deposits indicate balanced-fill type lake setting within the regime in foreland setting in relation to İzmir-Ankara suture. The centimeter-meter scale order cycles show symmetrical to asymmetrical transgressive-regressive cycles, which is due to repetitive change in the water-depth and/or fluctuating sediments influx. The cm-m scale cycles correspond to Milankovitch obliquity band and indicate climatic control linked with the earth`s orbital forces and local tectonics. In the sequence framework, the successions indicate marine transgression onto lacustrine en vironment in the region. The studied sections indicate a change from TST to HST in lacustrine-marine deposits. Lacustrine and Marine oil-shales in the studied area are interpreted that they have a possible source rock potential in the central and north, and in the south of the basin.
Citation Formats
B. Z. Afridi, “Sedimentology, cyclostratigraphy, sequence stratigraphy and geochemistry of the middle eocene lacustrine-marine oil-shales transition, Mudurnu Göynük basin, NW Anatolia, Turkey,” Thesis (Ph.D.) -- Graduate School of Natural and Applied Sciences. Geological Engineering., Middle East Technical University, 2019.