MINERALOGICAL AND GEOCHEMICAL PROPERTIES OF THE MIOCENE ROCKS OUTCROPPING AROUND TUZLUCA (IĞDIR-TÜRKİYE)

In this study, Miocene lithostratigraphic units (Turabi, Çincavat and Tuzluca formations) outcropping in the Neogene Kağızman-Tuzluca Basin in the west of Iğdır province were studied. The units are represented by evaporatic, carbonate and clayey rocks. The study aims to determine the mineralogical and geochemical properties of these rocks and to interpret the paleoenvironmental conditions. XRD (X-ray diffraction) whole rock and clay fraction analyzes, OM (Optical Microscope) studies, element determination with XRF (X-ray fluorescence) and, FE-SEM / EDS (Field emission scanning electron microscopy-energy dispersive X-ray spectrometry) studies of rock samples taken along the sections measured in the field were carried out for this purpose. Quartz, feldspar, mica, calcite, gypsum and halite minerals were determined in whole rock compositions of the samples. Smectite, illite, chlorite and paligorskite minerals were found in the clay fractions. It has been determined that feldspars altered to smectite by SEM and EDS studies. Optical microscopy and paleoenvironment studies indicate that the origins of gypsum, halite and palygorskite minerals are authigenic. It was also determined that calcite was authigenic and detritic, while chlorite, illite, quartz, feldspar and mica were detrital. The predominance of smectite, as well as the presence of chlorite, illite and palygorskite indicate that the basin developed under alkaline conditions, mostly hot and humid, and occasionally arid and cold conditions. In geochemical analyzes, the positive correlation of SiO2 with other major oxides (excluding CaO, MgO and SO3) is the input of clay and clastic materials, while the negative correlation of SiO2 with SO3 and CaO is associated with the decrease in the rate of CaSO4 sediments as a result of shallowing of the basin due to evaporation of water.