GLG 301 Lecture Notes - Lecture 14: Greenland Ice Sheet, Abraham Ortelius, Moraine
Document Summary
Ice sheet geomorphological features in michigan: glacial drift. Till refers to unconsolidated, unstratified, unsorted drift (moraines) An ancient (consolidated) till is called a tillite. Low relief region composed of till deposited at bottom of glacier or ice sheet. Drumlins subglacially formed till deposits that are molded into a hill. Asymmetry denotes glacial flow direction; often where ice was moving out of a basin. Eskers formed by subglacial outflow in tunnels (also channel deposits on top). Excavated for gravel hence now pits in places. Kettle lakes lakes formed where ice blocks were left behind by receding ice sheet, then later melted. Kame piles of stratified sediment formed as delta in front of glacier or in ponds on top. Glacial erratics boulders: erosional features. Glacial striations drag gravel over surfaces; obtain glacial flow direction. Glacial grooves usually attributed to subglacial dragging or larger objects, also possibly meltwater: the great lakes.
