What is a Moraine?
A moraine is a landform made of rock, soil, and sediment, collectively known as glacial till, that has been transported and deposited by a glacier. These materials accumulate at the edges or end of a glacier as it moves and melts.
Section 2: How Moraines Are Formed
Glaciers act like immense conveyor belts, scraping and plucking debris from the ground and valley walls as they advance. This material is carried along with the ice. When the glacier melts or retreats, it drops this load of unsorted till, creating distinct mounds, ridges, and blankets of debris known as moraines.
Section 3: A Practical Example
A well-known example is the Long Island Terminal Moraine in New York, USA. This extensive ridge marks the southernmost point reached by the Laurentide Ice Sheet during the last Ice Age. The hills that form the backbone of Long Island are this ancient moraine.
Section 4: Importance in Geology
Moraines are invaluable to geologists as they provide a clear physical record of a glacier's history. By studying the location, size, and composition of moraines, scientists can map the past extent of glaciers, understand their movement, and reconstruct ancient climate conditions.