Role of Geological Structures and Clay Minerals in the Occurrence of Landslides Along Mugling- Narayanghat Highway Section

Abstract

Each year Mugling-Narayanghat Highway section suffers from numerous landslides and debris flow. Geological structures and clay mineral content in soils have been investigated to understand their roles in the occurrence of landslides along Mugling- Narayanghat Highway section. In this section 13 large landslides in the Lesser Himalaya and the Siwaliks were investigated in detail and mapped to prepare landslide distribution map. From the landslides 11 soil samples were collected in the field, sieved and the finer fraction was subjected to X-ray diffraction analysis. X-ray analysis reveals that illite, chlorite and kaolinite were the main clay mineral in the soil. The main finding of the study is that in addition to the role of geology, geological structures and human activities, clay mineral content, particularly Illite, has significant role for the observed activity of the landslides in the study area.