Great Lakes Origin by Diastrophic Processes

Lake Erie

The floor of Lake Erie is divided into several basins. In the eastern section there is a deep, elongated trough with steep sides which may correspond with a fault or a fault-line scarp. The deepest section lies off Long Point, which would have constrained the current flow in the lake as it was excavated, resulting in increased current velocity where the overflow from the basin of Lake Ontario was constricted, causing the erosion of a deep trough. The character of the basins, channels, and shoreline of the lake suggest catastrophic currents have swept through the basin of Lake Erie extending it progressively towards the west.

A submerged ridge running southwest from Rondeau and Pte. au Pins on the Ontario shore may be a remnant of the western end of a smaller basin; Point Pelee and the submerged Lorain Ridge may also be eroded remnants of a former western end of the Lake Erie basin, that was breached by the currents. Or, perhaps the various basins formed simultaneously and became interconnected as they became enlarged by the action of the currents.

Possible stoss and lee features occur near the islands at the western end of the lake; the lee-side ridge west of Kelleys Island is consistent with powerful currents that flowed towards the west-southwest. Holcombe et al investigated this region and found overdeepened channels due to wind-driven circulation through restricted passages. They wrote [Holcombe, 1997]:

The islands and reefs bordering and lying within the western basin have bedrock cores which are erosional remnants of the more resistant upper Silurian and lower Devonian dolomites and limestones. Overdeepened channels between the islands have been sites of postglacial nondeposition, and probably erosion, due to intense wind-driven water circulation through these restricted passages. The Pelee-Lorain Ridge is interpreted as a late Wisconsinan end moraine upon which sand deposits have been concentrated.
Currents which eroded the basin of Lake Erie were probably similar to the ones that excavated Lake Ontario. At Kelleys Island, near the western end of Lake Erie, the bedrock is deeply grooved which suggests it was not fully consolidated during the events which excavated the lake basins. Pictures of the grooves can be found here.

See Map for the location of Kelleys Island.


Holcombe, T.L, J.S. Warren, L.A. Taylor, D.F. Reid, and C.E. Herdendorf. 1997. Lake floor geomorphology of western Lake Erie. Journal of Great Lakes Research 23 (2): 190-201.

Lewis, C.F.M. et al. 1996. Were the Ontario and Erie basins swept by catastrophic meltwater flooding? Geological Society of America Abstracts with Programs. 28 (3):76.

Bathymetry Maps:

New Bathymetry for Lake Erie and Lake Saint Clair
Bathymetry of Lake Erie and Lake Saint Clair 
Western Lake Erie poster (658K) 
Lake Erie
Lake Erie Bathymetry

© 1999 by Douglas E. Cox
The Creation Concept