232 Canadian Record of Science. 
Tuer St. LAWRENCE BASIN AND THE GREAT LAKES.* 
J. W. SPENCER. 
( Abstract.) 
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EsTABLISHMENT AND DISMEMBERMENT OF LAKE WARREN. 
This is the first chapter in the history of the great lakes 
and is subsequent to the deposit of the upper boulder clay, 
and therefore the lakes are all very new in point of geolo- 
gical line. By the movements of warping of the earth’s 
crust, as shown in the beaches—after the deposit of the 
later boulder clay—the lake region was reduced to sea level 
and there were no Canadian highlands northward of the 
great lakes. Upon the subsequent elevations of the con- 
tinent beaches were made around the rising islands. Thus 
between Lakes Hrie, Huron and Ontario a true beach is 
found at 1,690 feet above the sea, around a small island 
rising thirty feet higher. With the rising of the land, 
barriers were brought up about this lake region, producing 
lake (or perhaps gulf of ) Warren—a name given to the 
sheet of water covering the basin of all the great lakes. A 
succession of beaches of this lake have been partially worked 
out in Canada, Michigan, Ohio, Pennsylvania and New York, 
covering many hundreds—almost thousands—of miles. 
Everywhere the differential uplift has increased from almost 
zero about the western end of the Hrie basin to three, five, 
and, in the higher beaches, from five to nine feet per 
mile. With the successive elevations of the land, this lake 
became dismembered, as described in the succeeding papers 
—and the present lakes had their birth. The idea that 
these beaches in Ohio and Michigan were held in by glacial 
dams to the northward, is disproved by the occurrence of 
open water and beaches to the north, which belong to the 
same series, and by the fact that outlets existed where 
glacial dams are required. 
The Erie basin is very shallow, and, upon the dismem- 
berment of Lake Warren, was drained by the newly 
* Proc. of Am. Ass. Adv. of Se. 
