REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1900 rl07 



to the beaches by Spencer, though he did not recognize their 

 lacustrine origin. Only very generalized maps were published 

 in the writings,^ and no detailed description of any considerable 

 stretch of the shore has ever been printed. 



The map of Lake Iroquois (pi. 19) prepared to accompany this 

 report is not intended to be exact in minor features. Within 

 the area many drumlins and other high points were islands in 

 the lake. A few of these islands are indicated in the district 

 betw^een Syracuse and Oswego. For the boundaries in Canada 

 the writer has used the sketch map published by Dr J. W. 

 Spencer, and for part of the New York boundaries he is indebted 

 to Dr G. K. Gilbert. Toward the St Lawrence valley the shores 

 are not determined. 



Tilting of shore line 



In the papers referred to above was discussed the deformation 

 or differential uplift of the Ontario basin, which has largely or 

 wholly occurred since the extinction of Lake Iroquois, thereby 

 causing a present northward rise of the beaches. Between Rich- 

 land and Watertown the beach has an average slope of over 5 

 feet to the mile,^ or something over 135 feet in the 26 miles of 

 direct distance. 



The northward direction of the beach in this section with its 

 decided slope and well developed characters makes it probably 

 the most interesting and desirable portion of the whole Iroquois 

 shore line for the study of the differential elevation. Following 

 a suggestion of Mr Gilbert, the writer undertook the examina- 

 tion of the beach in order to discover if it indicated that any por- 



^ Spencer, J. W. Terraces and beaches about Lake Ontario. Am. jour, 

 sci. 1882. 24:409. 



The Iroquois beach; a chapter in the geological history of Lake 



Ontario. Roy. soc. Oan. Trans. 1890. 7:21, ser. 4. 



Deformation of Iroquois beach and birth of Lake Ontario. Am. 



jour. sci. 1890. 40:443. 



Gilbert, G. K. History of Niagara river. Com. Niag. reservation 6th 

 an. rep't. Alb. 1890. 



2 At Richland the railroad station has an altitude of 522 feet A. T., and 

 the upper bar is 44 feet above, or 566 feet. At Brookside cemetery, 2 miles 

 south of Watertown, the upper bars lie on, or above, the 700 foot contour 

 of the New York topographic map, Watertown sheet. 



