General Description of Lake Erie, 371 



described repeatedly, I refer to the map for their position and 

 length, and for further details to Kilbourne*s Gazetteer. I 

 may here mention that all the rivers of Lake Erie have sand- 

 bars at their mouths, preventing their being used as harbours for 

 vessels of considerable burthen. 



GEOLOGY OF LAKE ERIE. 



Extensive deposits of loose transported materials almost 

 altogether cover the fixed rocks of Lake Erie. The sugges- 

 tions thence arising have been already noticed in a general 

 view of the geology of the Canadas, transmitted to the Geolo- 

 gical Society. I shall now, in a very imperfect manner, 

 state their position and nature. 



On the south' shore. Professor Dewey * reports the highest of 

 the two banks or ridges, visible from the lake, to be composed, 

 in many parts, of the same substances as the present margin — 

 that is, of sand and gravel. The flat country at the foot of the 

 slope is every where (as at Dunkirk, Presqu'isle, Cleaveland, 

 &c.) composed of rich loam, with occasional and large patches 

 of sand, clay, and gravel. Professor Dewey saw a well in the 

 township of Weightsburgh, exhibiting the following appearances. 

 " From the top of the ground, the first three feet is a sandy 

 loam, then a coarse gravel, and then a layer of small stones of 

 the same kind, which we find on the present lake shore : these 

 three layers make about five feet. Beneath these are suc- 

 cessive strata of the same kind, to the bottom of the well, 

 which is about 20 feet from the surface. At the bottom of the 

 well, in the coarse gravel, and in a spring or rather subterra- 

 nean brook, there was found a piece of (apparently) bass-wood, 

 between two and three feet long, and two or three inches in 

 diameter. It was evidently a limb of a trunk, which is now 

 buried in the pebbles and gravel below : its direction was per- 

 pendicular, and its texture so little impaired that it was with 

 difficulty broken off. Lobster-shells y cockle-shells, and clam- 

 shells, of the same appearance, are found this depth from the 

 surface, as are now found on the lake shore." 



The deep channels of the rivers entering Lake Erie from the 



♦ Mitchell's edition of Cuvier's Theory of the Earth, p. 417. 



