(see also "Geologic v Engineering Terminology")

Backwater terrace – best developed in Kentucky, these are found at the mouths of tributaries to a river such as the that was depositing glacial age sands and gravels causing a temporary lake or pond to form in the tributary.

Bedrock – Used by engineers and geologists when referring to the limestones and shales that underlie, unconsolidated soils, glacial deposits or colluvium. A key term to know when talking to an engineer geologist.

Colluvium – A clay-rick deposit with poorly sorted limestone pebbles, cobbles, and slabs mantles many slopes, and when wet, easily moves downslope slowly by creep and also by sliding and slumping.

Failure - The rupture of a solid either unconsolidated or consolidated. Rupture contrast with the plastic deformation of slow creep.

Fault surface -- The surface between two sliding masses. This surface has striations which show its direction of movement. If present, a critical piece of evidence to note. Also known as the slip surface.

Glacial stages – In our region, there were at least three – Wisconsian (youngest) Illinoian (older) and pre – Illinoian Slope instability may differ between these three.

Laminated clay

Lateral spread – Mass movement in which a thick slide mass moves out horizontally on a relatively flat surface



Ice age deposits – These are of a wide variety and include wide ranging sizes of pebbles cobbles and boulders in a clay matrix (till), laminated take clays and silts as well as other deposited silts, sands and gravels deposited.

Mass wasting – A broad term referring to the movement a mass of soil or rock downslope towered by gravity rather than single grain by grain transports.

Ordovicion System – References to rocks such as those under Cincinnati that were deposited between to Ma. Local glacial deposits in contrast are most younger than 125,000 years.

Soil – defined either as material that supports plant life (by geologists) or any unconsolidated material above bedrock (by engineers).