LAKE ERIE'S EASTERN BASIN 14

Lake Erie's eastern basin is described. The eastern basin is separated from the adjacent central basin by the submerged Pennsylvania Ridge, which crosses the lake from Long Point, Ontario, to Presque Isle PA, and extends east to the head of the Niagara River at Buffalo NY. The eastern basin has an average depth of 18.9 m, a maximum depth of 64.0 m, and makes up 24% of the lake's surface area and 32% of its volume. The eastern basin receives most of its water from the upstream central basin but also has major river inflows on the north shore from the Grand River (Ontario) and on the south shore from Cattaraugus Creek (New York). Extensive areas of marsh and wetlands are found in Long Point Bay and in the lower reaches of the Grand River. Bottom substrates vary with exposed bedrock and deposits of sand and gravel along the south shore, whereas the north shore is dominated by clay and sand. Mud bottoms predominate in the deeper waters.