What Is a Drumlin?
A drumlin is an elongated, teardrop-shaped hill formed by glacial ice acting on underlying unconsolidated material or till. They are a type of glacial landform, typically found in clusters known as drumlin fields, creating what is sometimes called a 'basket of eggs' topography.
Section 2: How Drumlins Are Formed
Drumlins are formed beneath moving glaciers. As a glacier advances over loose sediment like glacial till, it can mold the material into these streamlined shapes. The blunt, steeper end, called the stoss end, faces the direction from which the ice advanced, while the gentler, tapered end, the lee slope, points in the direction of the ice flow.
Section 3: A Practical Example
A famous example of a drumlin is Bunker Hill in Boston, Massachusetts, the site of a major battle in the American Revolutionary War. The hill's distinct shape and composition are a direct result of glacial activity thousands of years ago, which shaped the historical landscape.
Section 4: Importance in Geology
Drumlins are important to geologists because they provide clear evidence of past glaciation and indicate the direction of ancient ice flow. Studying the orientation and composition of a drumlin field helps scientists reconstruct the behavior of former ice sheets and understand past climate conditions.