THE NIPISSING GREAT LAKES 



?holo by Michigan Deptrlment of Conieritliom 



PLATE 7.— CASTLE ROCK, ST. IGNACE, MICHIGAN 



A REMNANT OF THE NIPISSING SHORE. 



Nipissing beach is ten to twelve feet below the Algonquin, 

 but northward from the hinge line — extending from Great 

 Bend, Ontario, to Manistee, Michigan — they become widely 

 separated, until at Mackinac Island they are more than 175 

 feet apart, and over 360 feet separates them at Sault Ste. Marie. 

 In the Huron and Michigan basins the Nipissing beaches have 

 been lifted from the horizontal position along the same hinge 

 line as the Algonquin, but in the Superior basin they seem to 

 have a hinge of their own. Like the Algonquin beaches, the 

 Nipissing have also been destroyed in many places by the 

 work of the modern lakes — notably along the east side of the 

 Thumb north of Port Huron, along the east coast of Lake 

 Huron, and on both sides of Lake Michigan. Elsewhere they 

 are very pronounced, paralleling the present shore at no great 



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