In metamorphic rocks derived from stratified sedimentary rocks, direction of cleavage with respect to original bedding may cause a complex system of weak planes. As such slips may be of common occurrence in slopes made of above metamorphic rocks.

Crystalline igneous rocks like granites and gabbros and massive metamorphic rocks like marbles, quartzites and gneisses may be stable even with vertical slopes, whereas same cannot be said about chalk.

Gunite, is pneumatically applied mortar or concrete. The mixture of cement and sand (1:3) with little water is applied on face under pressure and is known to develop sufficient strength on settling and hardening.

The net result in each case is that surface material is natural ground or artificial fill- suffers a sinking downward movement.

A true landslide is a type of mass failure in which a superficial mass fails by moving as a whole along a definite surface of failure. The surface of failure may be planar or semi-circular in outline.

The various causes of rock mass due to role of water are: Increase in pore pressure, accumulation of water behind rock mass, lubrication of water etc. Water cannot get accumulated in front of rock and if it does happen in some conditions, it does not contribute greatly to failure.

Removal of vegetation cover especially trees is an external factor that has been a contributive factor in causing slope failures in a large number of cases, including notorious Nashri Slide near Ramban on National Highway-1 in Jammu Kashmir.

The nature of slope includes two important characters of slope. By nature of slope is meant here type of material of which land mass is made up and angle at which this particular mass is inclined with horizontal.

When mass involved is hard, brittle and coherent, such as massive igneous, sedimentary and metamorphic rocks, shear surfaces are broadly planar in character.

Rock toppling and falls are grouped along with slides although re may be little or no sliding involved in ir failure.