ML20052A531

Lake Erie Bathymetry & Sediments. One Oversize Drawing Encl.Aperture Card Is Available in PDR

ML20052A531
Person / Time
Site:	Perry
Issue date:	04/21/1982
From:	WESTON GEOPHYSICAL CORP.
To:
Shared Package
ML20052A522	List: ML20052A521 ML20052A531 ML20052A533
References
NUDOCS 8204280427
Download: ML20052A531 (2)

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LAKE ERIE BATHYMETRY AND SEDIMENTS Bathymetric contours drawn on NOAA 1:80,000 scale hydrographic charts 14825 and 14826 show an essentially smooth nearshore profile extending to a flat central basin. Two contour drawings prepared from the hydrographic charts are attached. A shallow projection extending northwestward from Fairport Harbor, Ohio represents increased deposition of-sediments from the Grand River which empties into Lake Erie at -

this point. At Cleveland the Cuyahoga River discharges in Lake Erie as indicated by the resulting shoaling offshore to the northwest.

Contour and isopach maps from a Lake Erie seismic reflection survey conducted by Wall (1968) show no evidence of structural deformation of bedrock or overyling unconsolidated materials. Wall states that the bedrock topography is generally agreed to be the result of subaerial erosion or glacial scour (p.- 102) rather than structure. The occurrence of a trough extending northeastward from Cleveland correlates l

with a narrow " gorge" at Cleveland (p. 102). The author i

attributes the origin of this gorge to fluvial erosion. The contour and isopach maps prepared by Wall for sediments within Lake Erie indicate that bedrock topography is covered by a

series of undeformed units of glacial and lacustrine origin.

i l Localized thickening of the unconsolidated units is the result of depositional and erosional events related to the late- and post-glacial history of the Lake Erie Basin. A lobate rise in l

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the "c" horizon, - as defined by Wall, across the longitudinal ,.

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axis of the lake corresponds to morainal deposits (p. 101) . An l elongate east-west trending depression of the "c" horizon in the south-central basin indicates erosion (p. 10 2) . The j distribution of sedimentary units indicates no evidence of faulting of the underlying bedrock or fault scarps at the lake

, bottom. .

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