As the ice melts and recedes, a variety of glacial landforms emerge. A. Till- materials deposited directly by glaciers 1. Glacial erratics - boulders derived from an outside area and transported by ice. End moraines - ridges of till which form at the terminus of the glacier. Commonly forms crescent-shaped ridges.
Moraines sometimes form natural dams so that lakes form upstream after the ice recedes.
Common throughout Ohio, Indiana, and Wisconsin. Terminal moraine - outermost end moraine which marks the greatest limit of ice advance. Forms from a stationary ice front. Recessional moraine - an end moraine that forms as the ice front stabilizes during retreat. Composed of eroded sediment and rock carried on the sides of the glacier against the valley walls.