The majority of Greater Cincinnati's hillsides consist of an underlying layer of bedrock approximately 200 feet thick, made up of 80% shale and 20% limestone. When shale is exposed to air and water, it quickly breaks down into an unstable material known as colluvium. Colluvium can range from several feet to 50 feet in thickness, and it is highly susceptible to erosion and landsliding. Some of the region's valleys contain lake clays. These clays are associated with landslides that can occur on the gentlest of slopes.
The instability of Greater Cincinnati's hillsides become more problematic due to excessive periods of precipitation, and construction methods that fail to address the underlying geology. Annually, the Greater Cincinnati region experiences millions of dollars in damages from landsliding, making it one of the more landslide susceptible areas in the country.
Date: Saturday April 1, 12 Noon to 4PM
Cost: $40 for Hillside Trust Members and $50 for non-members