HORIZONTAL PORTION OF THE ALGONQUIN PLANE 237 



Altitudes of the Algonquin Beach in the Begioii of Horizon tality — Continued. 



Locality. 



' Alti- 

 tude. 



i 



Authority. 



Reference. 





Feet. 







Bayport, Michigan 



607 



Lane. 



Michigan Geological Survey, An- 

 nual Report for 1900, volume 

 7, part 2, 1900, pages 47-51, 

 and 75-76. 



Sebewaing, Michigan . . . 



f605\ 

 1611 / 



Lane. 



Idem, pages 47 and 49. 



Kawkawlin, Michigan . . . 



610 



Cooper. 



Michigan Geological Survey, An- 

 nual Report for 1905, 1906, 

 page 349. 



Bridgeport, Michigan. , . . 



607 



Cooper. 



Tenth Annual Report, Michigan 

 Academy of Science, 1908, 

 pages 97-98. 



St. Charles, Michigan .... 

 Port Sanilac, Michigan. . . 



607 



Cooper. 



Loc. cit. 



605 1 



Leverett and 



Information given by Mr. Lev- 







Taylor. 



erett. 



Sarnia, Ontario 



605 ! 



Taylor and 



Canadian Geological Survey, 







(Toldthwait. 



Summarv Report for 1908, 

 1909, pages 112-114. 



Kettle Point, Ontario 



607 , 



Taylor and 



Canadian Geological Survev, 







(ioldthwait. 



Summarv Report for 1908, 

 1909, pages 112-114. 



CIrand Bend, Ontario ■ 



607 



Taylor and 



Canadian Geological Survey, 







Goldthwait. 



1 

 1 



Summarv Report for 1908, 

 1909, pages 112-114. 



Between the first two localities in this table there is a stretch of 150 

 miles in which no remnant of a beach at the 605-60T-foot level has been 

 discovered. The beach at Two Eivers is surely the Algonquin : the one 

 at Evanston until recently was regarded as the shoreline of a local lake 

 of the Michigan basin — Lake Chicago. The reasons for correlating it 

 with the Algonquin are: (a) its strength; (h) its uniform altitude of 

 603-610 feet around the south end of Lake Michigan; (c)the horizontal 

 attitude of the Glenwood and Calumet beaches of Lake Chicago, which 

 stand above it; (d) the presence in it of molluscan shells, which are ab- 

 sent from the higher beaches; (e) the occurrence of forest beds beneath 

 the beach gravels, believed to record the stage of low water during the 

 earlier part of the activity of Algonquin Eiver, and (/) evidences of ero- 

 sion of cetrain valleys tributary to Lake Michigan to low levels, previous 

 to the construction of this beach, as if to record the low-water stage just 

 mentioned.^^ 



"* On these points see Leverett : The Illinois glacial lobe. Monograph of the U. S. 

 Geological Survey, vol. 38, 1899, pp. 445-45.8. 



W. C. Alden : Chicago Folio. No. 81. Geological Atlas of the United States, U. S. 

 Geological Survey, 1902, pp. 10-11. 



Goldthwait : Bulletin of the Wisconsin Geological and Natural History Survey, no. 

 17, 1906. pp. 109-111, 118: and Bulletin of the Illinois Geological Survey, no. 7. 1908. 

 pp. 65-66. 



XVII— Bull. Geol. Soc. Am.. Vol. 21. 1000 



