عنوان مقاله [English]
Kashkan Formation comprises marl and clay minerals and characterized by hilly lands with forest and rain-fed area as well as high soil degradation potential. This research was conducted at the Merek watershed located in the Zagros Mountains, Kermanshah, Iran. The objectives of this study were to determine the dominant erosion and soil and rock mineralogy at the Kashkan Formation and Older terraces. Soil and rock sampling and analysis carried out within study area where subjected to gully erosion and landslide occurrence. Land-use at these areas includes forest and rain-fed agriculture. Soil and rock minerals explored through XRD technique and erosion intensity was estimated using MPSIAC model. The results showed that landslide and gully were dominant erosion in the forest and agriculture area, respectively. Both gully and landslide are triggered via crust as the primary step in degradation process. Mineralogical results also explored that smectite is dominant mineral in the landslide area, whereas quartz, calcite and dolomite are the other respective common minerals. Mineralogical properties in the gully areas at the older terraces (originated from Kashkan Formation), dominated by mica/smectite and vermiculite and other minerals approximately were as same as landslide area. The respective soil erosion intensity in the forest and rain-fed were 16.66 and 12.50 t ha-1yr-1. However, high interlayer space of smectite contributes to soil erodibility and consequently dissolve phenomenon for piping process.