POSTGLACIAL BIOTA OF THE GREAT LAKES REGION 1 13 



York. A similar lowering of the lake level is believed to have occurred in 

 the Michigan basin. 



2. Lakes Whittlesey and Saginaw 



A readvance of the ice raised the water to the Ubly outlet forming Lake 

 Whittlesey (altitude 735 feet). A small lake at the margin of the Saginaw lobe 

 has been called Lake Saginaw (Plate XLIX). The discharge was by way of 

 the Grand River into Lake Chicago and thence to the Mississippi River by way 

 of the Chicago outlet. 



3. Lake Wayne 



From the Whittlesey beach the lake dropped 80 or 85 feet to a lower beach 

 known as the Wayne beach (altitude 660 feet). "The drop in the lake level 

 was, of course, due to a movement of retreat on the part of the ice front. The 

 Wayne beach lies at a level in the Saginaw Valley barely below the head of the 

 channel, which had served as the outlet of Lake Saginaw. At the same time it 

 is quite certain that no outlet was open toward the northwest through the straits 

 of Mackinac. The outlet at the time of this beach seems to have been in the 

 east along the ice margin, where it rested against the hills south of Syracuse. " 5 



4. Lake Warren 



Continued shifting of the ice border caused the waters of Lake Saginaw 

 and Lake Wayne to become confluent and a large lake developed known as 

 Lake Warren (Forest beach, altitude 680 feet), which discharged into Lake 

 Chicago via the Grand River. To the eastward, it extended as far as the 

 Finger Lake region of northern New York (Plate L). As the ice melted back 

 into the Ontario basin passages were opened for the eastward discharge of the 

 waters of Lake Warren past Syracuse, New York, to the Mohawk Valley and 

 thence into the At' antic Ocean by way of the Hudson River. 



5. Lake Lundy {Lakes Dana and Elkton) 



A later stage of the Warren water is called Lake Lundy, during which time 

 two lake beaches (Grassmere, 640 feet; Elkton, 620 feet) were formed; the 

 discharge was eastward past Syracuse. Taylor remarks that "these beaches 

 mark a transition stage of the lake waters — the transition to Lake Algonquin, 

 the largest of the glacial lakes in the Great Lakes region" (Plate LI). 



It will be noted that there are recorded six distinct stages of the waters of 

 the Huron-Erie-Ontario basins; four stages with outlets via Chicago, and two 

 stages with probable outlets eastward via the Mohawk Valley. This, of course, 



5 Taylor, An. Rep. Smith. Inst., 1912, p. 306. 



