Influence of Geological Structures and Weathering in Formation and Destruction of Cone-Shaped Rocky Houses of the Kandovan Village, Iran

Abstract

The Kandovan is a touristic and historical village which is located 65 km far from the Tabriz city, Northwest of Iran with views of cone-shaped rocky houses. These rocky houses created by erosion and weathering of pyroclastic rocks (ignimbrite) of Sahand volcano. Based on geological studies, it is recognized that the discontinuity systems of rocks and erosion have an important role in the formation of these cone-shaped rocks. Destructive factors in the study area can be divided into natural processes (weathering and erosion) and human activities. The XRD analysis carried out on surface rocks samples, highlighted that there are no traces of clay minerals and chemical weathering. So, physical weathering of rocks is dominant. To assess their durability physical properties test has been used. In this study, emphasis is placed on hardness, density, porosity, water absorption and saturation coefficient of rock mass of Kandovan. The rock mass of Kandovan has hardness, porosity, water absorption and dry density equal to 20–25 MPa, 45–50 %, 8–12 % and 15 kN/m3 respectively. Test results highlight that the high value of porosity and water absorption and low density of rocks are main effective factors to assess durability of rocks to environmental factors. These properties along with human activities have important roles in the destruction of the cone-shaped rocky houses of Kandovan village.