DIATOM CONTENT AND PALAEOECOLOGICAL CHARACTERISTICS OF LATE MIOCENE-EARLY PLIOCENE AGED DIATOMITES IN TAHAR-GüZEL？Z (NEV？EH？R)

Seventy-three species of 21 different diatom genera were identified from three stratigraphic sections which are located in the late Miocene-early Pliocene volcanosedimentary units in Tahar and Güzel？z (Nev？ehir) areas. One of these sections was measured in the Tahar area (in the late Miocene age Bayramhac？l？ Member of ürgüp Formation), and the two sections were measured in the Güzel？z area (early Pliocene age K？？lada？ Member of ürgüp Formation). When evaluated of the investigated area diatomite’s palaeoecological properties by considering the distribution of numerical values (in 20 microscopic slide area) of the determined diatom genus and species; It have been determined that, when the formation of the diatomite at all three locations, the lake water has neutral and acid properties. At the Tahar and Güzel？z-2 locations the lake water was fresh water feature, also, in the Güzel？z-1 location the lake water was initially as fresh water feature and than changed to bitter water character towards to top of the section. At the Tahar location (late Miocene); lake water’s level and temperature was high, the bottom of the lake was muddy. The nutrient ratio of lake water was initially low-moderate, later increased towards to top of the section. Lake water's oxygen ratio was initially high, later in the middle level. At the Güzel？z–1 location (early Pliocene); lake water’s level and nutrient was variable. There were plants at the bottom of the lake. Lake water's oxygen ratio was initially high, later in the middle level. The lake water’s temperature ratio was initially low, later increased towards to top of the section. Also, lake water's oxygen ratio was initially high, later in the middle level. At the Güzel？z-2 location; lake water’s level, temperature and nutrient was high