442 PLEISTOCENE OF INDIANA AND MICHIGAN. 



LAKE ROUGE. 



With the beginning of Lake St. Clair and the fall of the waters in the Lake Erie basin Lake 

 Eouge was formed between Detroit and the barrier at Limekiln crossing by an expansion of 

 Detroit Kiver. The lake spread some distance over low ground on the Canadian side, but its 

 larger part was over the flats of Kouge Kiver west and southwest of Detroit. 



Rouge Lake was small, but during the time of Lake Algonquin its waves formed a faint 

 beach which belongs to it alone and does not He in the plane of any other beach. This beach 

 appears as a distinct wave-cut notch on the gently sloping clay plain west and southwest of 

 Wyandotte and as a distinct low beach ridge of gravel on the north and northeast sides of Grosse 

 Isle, especially near the lighthouse and for a mile or two to the south. Its altitude is 589 feet. 



At the lower level of the Nipissing waters Lake Rouge was so reduced in area that it was 

 almost obliterated and probably had no waves of any importance. No distinctly wave-made 

 features were found for this level, but low, sandy ridges at Wyandotte and Ecorse, 6 or 8 feet 

 above Detroit River, probably mark its position. 



LAKE ERIE. 



SEPARATION FROM GLACIAL LAKES. 



Until its separation from Early Lake Algonquin Lake Erie was a part of the Huron-Erie 

 glacial waters described above, Lake Lundy being the last stage. Immediately following its 

 separation from Early Lake Algonquin Lake Erie was also separated from the glacial waters of 

 the Lake Ontario basin, and ceased to be a glacial lake. After this separation the only changes 

 which affected it were slight uplif ts of the land and large changes of volume in the water which it 

 received and discharged. The largest uplift which affected the Lake Erie basin occurred before 

 the lake became independent — during the time of Lake Lundy. The span of Lake Erie's 

 existence as an independent lake is the precise time equivalent of the duration of Niagara River 

 and the Falls. 



SEQUENCE OF STAGES DURING LAKE ALGONQUIN. 



During Early Lake Algonquin Lake Erie stood at a somewhat lower level than now, and 

 received a large volume of inflow through Detroit River, which of course gave it a large outflow 

 at Buffalo. The Buffalo outlet, however, was on a rock sill with only very slight fall, and it 

 remained firm and the lake was held steadily at one level. This was Lake Erie's first high 

 stage, and its beach in the western part of its basin was probably 20 to 30 feet lower than 

 the present surface. 



Soon, however, an outlet was opened at Kirkfield, Ontario, and this took the whole 

 discharge of the upper three lakes away from Lake Erie, causing a reduction of outflow at Buffalo 

 amounting to about 85 per cent and lowering the level of Lake Erie 10 to 15 feet. This first 

 low stage of Lake Erie lasted throughout the Kirkfield stage of Lake Algonquin. It therefore 

 occurred before the Algonquin uplift, and its beach was probably 10 or 12 feet lower than in 

 the preceding (Early Lake Algonquin) high stage. 



The first low stage of Lake Erie was ended by the uplift which raised Kirkfield, closing the 

 outlet there and sending the discharge of the upper lakes back to Port Huron and Chicago. 

 The uplif t affected the outlet of Lake Erie at Buffalo much less than it did that at Kirkfield, 

 raising the former probably only 20 or 30 feet and backing the water up this much in the west 

 end of the lake. The closing of the Kirkfield outlet gave Lake Erie a large volume of discharge 

 and a high stage on its shores, and this condition lasted until the retreating ice opened a lower 

 outlet in the Ottawa Valley and Lake Algonquin came to an end. 



EFFECTS OF ALGONQUIN UPLIFT. 



In the Lake Erie basin the area of horizontality for the Whittlesey beach extends about to 

 Ashtabula, Ohio, and for the Warren beach about to the Ohio-Pennsylvania line. The hinge 

 line for the Algonquin water plane, if produced as a straight line from the southern part of Lake 



