Morphotectonic development of surface karst in Western Taurus (Türkiye)

The Taurus Mountains, the most important karst terrains of Turkiye, contain many surface and subsurface karst landforms, and the morphometric features of these landforms provide important data on the geomorphological and morphotectonic development of karst areas in the Taurus Mountains. Micro and macro karst depressions are the most important surface landforms in the Western Taurus Mountains. In this study, a total of 7093 micro depressions (doline) and 74 macro depressions (polje) located in the Western Taurus Mountains were detected and morphometric properties were calculated. The poljes developed within the Beydaglari Autochthon and Lycian nappes, while the dolines developed mainly in the high karst plateaus within the Beydaglari Autochthon. As briefly described below, the morphotectonic evolution of both landforms is closely related to the tectonic evolution of the Western Taurus Mountains. As a result of this tectonic activity, the Lycian Nappes from the northwest and the Antalya Nappes from the east thrust over the Beydaglari autochthon, leading to the development of nappes, reverse faults, and fold systems in the study area. The Western Taurus began terrestrialization starting from the Oligocene and began to erode from the Miocene. This erosion process led to the development of valley systems within the Western Taurus region. The NE-SW and NW-SE directional normal faults have developed under the influence of extensional tectonics since the Miocene. This extensional tectonism has caused widespread development of the poljes in the study area. Furthermore, with the lowering of the karst base level, dolines and paleovalleys began to develop in limestone areas at higher elevations. All morphometric and morphotectonic processes reveal that the extension of both doline and polje areas in the study area are parallel to the elongation of tectonic structures in the Western Taurus.