THE REPUTED MARINE BEACH OF COVEY HILL 475 



the lake of the same name. Indeed, at the head of Lake Ontario is the 

 Bell terrace, with which this spillway might be correlated if the body of 

 water were as great as that of Lake Iroquois. 



The Eeputed marine Beach of Covey Hill 



One of the lower beaches on the northern side of Covey Hill occurs at 

 523 feet above tide. This is the corrected height of the beach hitherto 

 mentioned at 450 feet, as pointed out by Fairchild, with the new meas- 

 urement taken from a Canadian topographic map (Chateaugay sheet). 

 The beach referred to has been accepted by Woodworth, on the sug- 

 gestion of Gilbert, as the upper limit of marine beaches, and later insisted 

 on by Fairchild. Of this no evidence has been offered beyond the assump- 

 tion that it was at the height of marine deposits elscAvhere, and on ac- 

 count of the coarseness of the material that it could not be expected to 

 preserve the shells, of which none have been found. But on making 

 allowance for post- Glacial deformation this shoreline is found to be at 

 least 160 feet above the marine deposits a short distance southeastward, 

 near Moores Junction, 340 feet (Woodworth). The assumption that 

 shells should not be expected in the ill-assorted sand, gravel, and larger 

 stones is not supported, for east of Morrisburg, north of the Saint Law- 

 rence Eiver, coarse gravels, with stones from 12 to 20 inches in diameter, 

 have their interspaces filled with Saxicava and other shells. These indi- 

 cate that if the terraces of Covey Hill had been marine there was no 

 reason why the shells should not have been preserved. 



The beach occurring on the northern flank of Covey Hill, at 523 feet, 

 is very strong, with much coarse materials. Crossing the plain country 

 for 40 miles to Montreal, marine terraces are there found, but at lower 

 elevations, except one deposit of different character. This is composed 

 of free sand with marine shells at an altitude of 575 feet above the sea, 

 which corresponds to Dawson's locality at 560 (corrected to 572 feet 

 for change of datum from lake Saint Peter to mean tide at New York). 

 But it is at a different locality, where I have myself collected the shells. 

 These marine deposits are covered by several feet of an earthy mantle 

 containing stones. On the surface there is no beach structure whatever, 

 like that of the great shoreline of Covey Hill, at a lower altitude. 



As no calculations have been made from the earth movements show- 

 ing that the Covey Hill 523-foot beach was formed at sealevel; as no 

 marine shells have been found in it ; as it is higher than the marine ter- 



