Glacial Lake Iroquois was a prehistoric proglacial lake that existed at the end of the last ice age approximately 13,000 years ago. The lake was essentially an enlargement of the present Lake Ontario that formed because the St. Lawrence River downstream from the lake was blocked by the ice sheet near the present Thousand Islands. The level of the lake was approximately 30 m (~100 ft) above the present level of Lake Ontario.
The lake drained to the southeast, through a channel passing near present day Rome, New York. The Rome Sand Plains has several sand ridges that geologists think were formed at this time. The channel then followed the valley of the Mohawk River to the Hudson River.
The lake was fed by Early Lake Erie, as well as Glacial Lake Algonquin, an early partial manifestation of Lake Huron, that drained directly to Lake Iroquois across southern Ontario, along the southern edge of the ice sheet, bypassing Early Lake Erie.
The subsequent melting of the ice dam resulted in a sudden lowering of the lake to its present level, a potential trigger for the Younger Dryas episode.
Read more about Glacial Lake Iroquois: Remnant Shorelines
Famous quotes containing the word iroquois:
“While the very inhabitants of New England were thus fabling about the country a hundred miles inland, which was a terra incognita to them,... Champlain, the first Governor of Canada,... had already gone to war against the Iroquois in their forest forts, and penetrated to the Great Lakes and wintered there, before a Pilgrim had heard of New England.”
—Henry David Thoreau (1817–1862)