Diatom community and palaeoenvironmental characteristics of Taşkınpaşa (Nevşehir) and İncesu (Kayseri) diatomites

In this thesis study, diatom community and palaeoenvironmental characteristics of Taşkınpaşa (Nevşehir) and İncesu (Kayseri) diatomites were examined which are taken places in late Miocene–Pliocene aged volcanosedimentary units. Totaly two stratigraphic sections were measured in the study area. One of these sections was measured from Taşkınpaşa region and the other section was measured from İncesu region. A total of 14 samples were taken from the measured sections and 26 species of 19 different diatom genera were identified in Taşkınpaşa and İncesu locations. It was determined that pennate forms are more abundant than centric forms in the defined species and the lake water has fresh water properties in both localities. In Taşkınpaşa location; It have been determined that, when the formation of the diatomite, lake water's level was low, the bottom of the lake was initially muddy later covered with plants, lake water was initially oligotrophic properties later changed in eutrophic and mesotrophic characters in time, the nutrient ratio of lake water was high in bottom and upper levels of the section but it was moderate at the middle level of the section. The lake water has alkaline (pH >7) properties. Lake water's oxygen ratio was middle level. In İncesu location; It have been determined that, when the formation of the diatomite, lake water's level was high, the bottom of the lake was rocky, lake water was initially oligotrophic properties later changed in eutrophic character, the nutrient ratio of lake water was low in bottom level of the section but it was high at the middle and upper levels of the section. the lake water was neutral (pH=7) or acid ((pH >7) properties at the bottom level of the lake, than it changed in alkaline (pH>7) character towads to middle and upper levels of the section. Lake water's oxygen ratio was initially low level. Keywords: Diatom, Diatomite, Late Miocene-Pliocene, İncesu, Kayseri, Nevşehir, Palaeoenvironment, Taşkınpaşa. October, 2018; 68 pages