Drumlin

A drumlin is an elongated hill, often compared to an inverted spoon or a half buried egg, built by glacial ice acting on unconsolidated till or ground moraine; the word comes from the Irish droimnin, little ridge, first recorded in 1833. Drumlins rarely occur alone, and a cluster of them is called a drumlin field or swarm, producing what geologists call basket of eggs topography. They are made mostly of glacial till and typically occur near the margins of past glaciers and within zones where the ice sheet once flowed quickly, often alongside other glacial features such as tunnel valleys, eskers and areas of exposed, eroded bedrock.