RIDGEWAY AND MAUMEE BEACHES. 467 



shore-lines down to sea-level, as in the case of the Iroquois, and to nearly as 

 perfect an extent in the Algonquin beach. Consequently, it is necessary to 

 rely more fully upon the perfection of the structure of the deserted shores, and 

 upon their positions, which would preclude their formation in confined lakes. 

 Such conditions exist in Ontario, Michigan and Ohio, where extensive sur- 

 veys have been made. 



The lower of these shores, as the Ridgeway beach,* like those before 

 named, were formed about bodies of water which opened only toward the 

 north or east. But, ascending a little higher, the Maumee beach f occurs at 

 altitudes which permitted its formation in water having free communication 

 to the Ohio and Mississippi valleys by two depressions. Above this plain, 

 there are higher gravel terraces and plains in Michigan and elsewhere, 

 notably those between Kalamazoo and Marshall, with an elevation of a 

 little more than 900 feet above the sea. From them the country falls away 

 by steps toward the lakes ; but the sheet of water which they once bounded 

 had at least five connections with the drainage of the Mississippi system. 

 Other higher terraces about more insular points are found in the same region, 

 and farther north, in Michigan, they are said to occur on the summit of the 

 highest land east of Grand Traverse bay, at 1,682 feet above tide. 



In Ontario there are well-marked sea-cliffs carved out of the Niagara 

 escarpment, as westward of Col ling wood, especially at elevations of from 

 1,200 to 1,425 feet above tide. At various intervals between the plain of 

 the Algonquin beach and the highest land of the peninsula (1,709 feet) 

 there are also terrace and beach deposits moulded out of the drift. These 

 remnants of shores are seen to within 20 feet of the highest point of land. 

 The shore markings of these elevated lands are rendered more certain by 

 the perfectly water-worn stones, and the extent of the beach and terrace 

 structure. The sea-clifis are too deeply graven to represent evanescent coast 

 lines. But all of these records are interrupted, owing to the topography of 

 the country, erosion by atmospheric agencies, and the recent Pleistocene de- 

 formation of the region. 



Some of the positions of the surveyed coast lines are shown on the accom- 

 panying map ; but for the detailed list of localities reference should be 

 made to a paper on " High level shores in the region of the Great Lakes 

 and their deformation." J 



Again, at Dog lake, north of Lake Superior, Professor H. Y. Hind ob- 

 served terraces at 1,425 feet above the sea.§ 



After allowing for all the measurable Pleistocene and recent deformation 

 of the region, these elevated shores stand so high above every natural bar- 



* " High Level Shores in the Regioa of the Great Lakes and their Deformation," by J. W. Spencer : 

 Am. Journ. Sci., vol. XLI, 1891, p. 207. 

 flbid., p. 208. 

 t Loc. cit. 

 gAssiniboine and Saskatchewan Expedition, 18.59,|p. 120. 



