PELHAM BAY, NY

ROCHES MOUTONNEES. Note the asymmetric bedrock island. Such aysmmetric bedrock hills are common in areas that have been covered by flowing glacial ice. The gentle slopes face the direction from which glacial ice advanced; the steep slopes face the direction towards which the ice was flowing. It is assumed the hills were symmetrical before being subjected to ice action. The ice smoothed the upstream faces of the hills; on the downstream sides, the ice tore away blocks of rock, creating steep faces.


© 2001
Photo by David J. Leveson