عنوان مقاله [English]
The purpose of this study was to evaluate karst development in the Bid Sorkh region, East of Sahneh by identifying karst geomorphological phenomenon and geological and tectonic characteristics. Carbonate units in the study area, are widespread and belong to the Fahliyan Formation which has upper Cretaceous age. Many tectonic structures (joints, fractures and faults) and geomorphological phenomena of karst such as microkarren, dissolution cavities and fissures, caves and karst springs in the area have been observed in this area. According to the study of rock thin sections, from 4 stations, rocks were of crystalline Micritic limestone, wackestone and crystalline limestone with carbonate cement types. A total of 12 samples were prepared to evaluate physical properties. The average weight per unit volume of carbonate rock samples were 2.54 g/cm3 and a porosity of 2.57% was measured. According to XRD analysis performed on the joint filling material, these are composed of clay minerals which are mainly consisted of kaolinite, illite and montmorillonite. Based on this study, the appropriate combination of lithology, various discontinuities, weather condition, the climate of the area and abundance of geomorphological phenomena are evidence of karst development in this region.