During the last Ice Age large ice sheets formed in North America and Northern Europe. The amount of water trapped in these ice sheets caused sea level to drop by about 125 meters. Glacial Erosion, Transportation and Deposition Rock and sediments are eroded and incorporated into a glacier by several processes. The most important are abrasion, plucking, and freezing-on. Abrasion occurs when debris-rich ice slides over bedrock abrading it like sand paper on a block of wood.
Abrasion is particle by particle erosion.
Plucking occurs when ice flows into or refreezes in fractures in the bedrock. The ice wedges and removes blocks of bedrock and incorporates it into the glacier. This process is most rapid in areas where water is refreezing near the bed. In other cases sediment can be frozen into a glacier either grain by grain or in mass. Glacier erosion is most rapid in areas where the ice is flowing at high velocity, material is freezing to the bed, and there is plenty of water.