142 PROCEEDINGS OF THE ALBANY MEETING 



POST-GLACIAL MARINE SUBMERGENCE OF LONG ISLAND 

 BY HERMAN L. FAIR CHILD 



(A'bstract) 



Recent study of the extensive sand-plain along the south side of Long Island 

 has developed new facts relating to its origin. All the features of the plain 

 and its relation to neighboring uplifted territory indicate that it was formed 

 beneath the sea. The amount of the submergence and later uplift is shown by 

 the map published as plate 10 in volume 27 of the Bulletin. 



Presented by title in the absence of the author. 



It was possible at this point to insert an additional paper by G. Fred- 

 erick Wright. 



EXPLANATION OF THE ELEVATED BEACHES SURROUNDING THE SOUTH END 



OF LAKE MICHIGAN 



BY G. FREDERICK WRIGHT 



(Ahstract) 



These beaches are three in number^ — the Glenwood beach, 60 feet above the 

 present lake level ; the Calumet beach, 40 feet, and the Tolleston beach, 20 feet. 

 The most difficult facts to account for are numerous peat deposits underneath 

 the Calumet or second beach. To explain this accumulation of peat in that 

 position, resort has been had to the supposition of a temporary land elevation. 



But a simpler explanation follows from considering the variations in amount 

 of water passing through the Chicago outlet, occasioned by the opening of the 

 various channels giving access to Lake Michigan of the vast amount of water 

 stored up in the glacial lakes which occupied the Lake Erie basin. Lake 

 Maumee stood 200 feet above Lake Michigan and was lowered 50 feet when 

 the Ubly outlet was opened. Lake Whittlesey stood 150 feet above Lake IMiclii- 

 gan and extended over an area of several thousand square miles. This was 

 lowered 50 feet on the opening of the Saginaw outlet. Lake Warren stood 100 

 feet above Lake Michigan and covered an area much larger than Lake Whit- 

 tlesey, and it was lowered to approximately the jiresent level when the i-etreat 

 of the ice opened the Mackinac channel. 



Presented in abstract extemporaneously. 



Discussion 



Dr. Frank B. Taylor: The study of the history of Lake Erie during and 

 after Lake Algonquin shows the same sort of oscillations of the level of Lake 

 Erie as those mentioned by Professor Wright for the south shore of Lake 

 Michigan. In the case of Lake Erie the cause was the division of the outflow 

 of the three upper lakes through Ontario without flowing through Lake Erie. 

 This division occurred twice and produced two low stages of Lake Erie -svhen 

 the level was 12 or 15 feet lower than now. 



