12 Spencer — Deformation of Algonquin Beach, 



Art. II. — Deformation of the Algonquin Beach, and Birth 

 of Lalce Huron ; by J. "W". Spencer. 



From the ship's deck, my attention to the high terrace, 

 which skirts the coast of Georgian Bay, was first attracted. 

 But long before, fragments of this ancient shore-line were used 

 by the Algonquin Indians, in the same manner as the Iroquois 

 tribes had trailed over the " Ridge Roads" of Ontario and 

 Erie. Mr. Sanford Flemming, C.E., described in 1853, some 

 of the drift ridges at the head of Georgian Bay, and recog- 

 nized certain high level beaches."* Later the Geological Survey 

 of Canada measured the elevation of some of the raised ter- 

 races, f But those early investigators did not recognize either 

 the extent of the beaches or their deformation from the water- 

 level. Xo systematic explorations of the old shores were 

 made until the summers of 1887 and 1888, when the writer, 

 assisted by Professors "W. "W. Clendenin and W. J. Spillman 

 surveyed portions of them. In the autumn of 1887, Mr. G. 

 K. Gilbert visited some of the Canadian terraces. In August, 

 1888, I abruptly left the field and reported some results 

 before the Cleveland meeting of the American Association for 

 the Advancement of Science.;}; Some references to the Geor- 

 gian Bay beaches were made in " The Iroquois Beach, etc.,"§ 

 and later Mr, Gilbert generalized upon the history of the 

 Upper Lakes, in an interesting paper entitled " The History of 

 the Niagara River," wherein some of his raised shore-lines 

 were taken from my survey, unpublished portions of which 

 having been furnished to him. 



Upon the Canadian side of the lakes, there are well pre- 

 served shore-lines, marking the same episodes, as those upon 

 the American side, when all the lakes were covered by a com- 

 mon sheet of water (the Warren water). These raised beaches 

 have been more or less surveyed, but they belong to an episode 

 earlier than that recorded in the beach, which confined the 

 waters to the Upper Lake basins not embracing that of Lake 

 Erie. This beach, which skirted the head of Lake Huron, 

 cutting off the waters from the Erie basin, is now submerged 

 at its southern end, but it rises as a conspicuous feature in the 



♦Valley of Nbttawasaga, Can., Jour. Toronto, vol. i. 1853. 



+ Geological Survey of Canada. 1863. 



\ •• Notes on the Origin and History of the Great Lakes of North America,'' 

 by J. W. Spencer. Proc. A. A. A. S.. vol. xxxvii. 1888. 



£ "The Iroquois Beach, a Chapter on the Geological History of Lake Ontario." 

 Read before Phil. Soc. Wash., Jan. 1888, and Roy. Soc. Can., May, 1889. Proc. 

 Phil. Soc. Wash.. 1888. Trans. Roy. Soc. Can., 1889. 



|| Sixth Annual Report of the Commissioners of the State Reservation of 

 Niagara for 1889. 



