Most rockfalls in Ohio involve massive beds of sandstone or limestone. Surface water seeps into joints or cracks in the rock, increasing the weight of the rock and causing expansion of joints when it freezes, thus prying blocks of rock away from the main cliff. Certain inherent geologic conditions are a prerequisite to the occurrence of a landslide in a particular area. The presence of one or more of the following conditions can serve as an alert to potential landslide problems. Steep slopes .
All landslides move downslope under the influence of gravity.
Therefore, steep slopes, cliffs, or bluffs are required for development of a landslide, especially in conjunction with one or more of the conditions listed below. Jointed rocks . During periods of cold weather, this moisture freezes and causes the rock masses to be pried apart along the joint. Fine-grained, permeable rock or sediment . These materials are particularly susceptible to landslides because large amounts of moisture can easily enter them, causing an increase in weight, reduction of the bonding strength of individual grains, and dissolution of grain-cementing materials.