Sedimentological features of şelmo formation (Atabağı surroundings, northwest of Siirt province)

This study, whose thesis subject is "Sedimentological Features of Şelmo Formation (Atabağı Surroundings, Northwest of Siirt Province)", covers Atabağı Town and its surroundings in Baykan District, in the Northwest of Siirt Province. This thesis study was carried out in 4 stages: literature, field, laboratory and office studies. The stratigraphic relationships of the allochthonous and autochthonous units in the study area and its surroundings with the Şelmo Formation were examined as a result of literature review and field studies. Within the scope of this thesis, 7 stratigraphic sections were measured from the Şelmo Formation located in Atabağı Town and its surroundings. 27 hand samples were taken to make thin sections from mudstone, sandstone and conglomerate found in different locations. Thin sections of these hand samples were examined under a polarizing microscope to determine petrographic properties. As a result of sedimentological studies, 13 facies and 3 facies communities were determined. In the south of the Şelmo Formation outcrops in the study area, the Oferhan Tepe and Cirban sections, in the west of Atabağı and in the northeast of Mergezan Creek sections, the Menderesli River facies community is effective, The Lake facies community is effective in the middle levels of the Gazenare Hill and Giremeli Hill sections measured in the northwest of the outcrops of the Şelmo Formation in the study area, It was evaluated that the Örgülü river facies community was effective in the middle-upper levels of the Gazenare Hill and Giremeli Hill sections measured in the northwest of the outcrops of the Şelmo Formation in the study area, and in the middle-upper levels of the Tilleyri Hill section measured in the northeast of the outcrops of the Şelmo Formation in the study area. Sedimentary structures and deformation structures in the study area were determined. Old flow directions were determined from the sedimentary structures. By determining the old flow directions, the source area was determined and the paleogeographic model of the basin was presented for the first time within the scope of this study. Keywords: Sedimentology, Facies analysis, Şelmo Formation, Siirt, Upper Miocene