Geology & History of the Niagara Escarpment

The Niagara Escarpment has origins dating back some 430 to 450 million years ago. During this time it was covered beneath a large ancient sea, which lay in a saucer shaped depression in the state of Michigan, now known geologically as the Michigan Basin. Rivers flowing into this sea carried sand and clay, which were deposited as sediment. The sea flourished and became rich with plant and animal life, which eventually died, and over time became compressed into many layers of sedimentary rocks. The ancient sea began to become shallower as the Michigan Basin began to rise, due to disturbances in the Earth’s crust.  steep

During the next millennia the seas withdrew, leaving the earth’s surface exposed. Pre-glacial rivers and streams began carving out the body of the plain, creating valleys and ridges. A series of four Ice Ages, occurring within the past two million years, covered North America with thick ice sheets. In time the glaciers began to retreat, eroding away the soft layers of the Escarpment and leaving the hard dolomite limestone exposed at its surface. The great ice sheets also widened the valley’s floor, making its sides more steep, and created caves and cliffs. Still today ice, wind, and water continue to erode the rock that makes up the Escarpment, changing its face in an unending process.