ABSTRACT
The hilly state of Mizoram with young geological formations generally consists of thin topsoil overburden overlying the interbedded strata of different sedimentary rocks. The predominant sedimentary rocks are sandstone, siltstone and shale. Being young formations, the rock strata are weak and susceptible to internal erosion. Shale formations are particularly treacherous as they disintegrate on exposure to air and water. The state land, receiving high rainfall of over 2,000 mm/year and falling under seismic zone V, is vulnerable from a civil engineering construction point of view, especially when open cuts are needed. With high fines in topsoil and weak rock formations, the local construction material does not satisfy quality requirements; thus, sand and rock for construction works are imported from neighbouring states.
