Answer:
A moraine is an irregular, usually thin till layer laid down by a retreating glacier.
Step-by-step explanation:
A moraine is an irregular, usually thin till layer laid down by a retreating glacier. It is formed when a glacier picks up rocks, dirt, and other debris as it moves and then deposits it as the glacier retreats. Moraines can be found in areas where glaciers have retreated in the past and can be used to study the history of glacial movement and climate change.