Section IV, 1889. . [ 121 ] Trans. Eoy. Soc. Canada. 



XI. — The Iroquois Beach: a Chajjter In the Geological Hidory of Lalce Ontario} 

 By Prof. .1. W. Spencer, M.A., Ph. ])., F.a.S. 



{Communicated by Dr. T. Sterry Hunt, May 5, 1889.) 



(1.) Introduction. — -The gTavL4-rid<çes, at high elevations above the luoderii 

 surface of Lake Ontario, attracted the attention of the aboriginal tribes of Indians, on 

 account of their afFordiug dry pathways through an otherwise often muddy country, 

 composed of clay .soil. These traiLs were used as long as the great Iroquois confederation 

 ^vere masters of the lake region, and subsequentl}', they were replaced by the roads of 

 the early white settlers. Fragment.s of the old shore lines received local names. Thus 

 we find that that salient portion of the greatest of the old beaches, Burlington Heights, 

 — a spit at the extreme western end of the lake — was a strategic point in the last Anglo- 

 American war of 1812-15, during which a battle was fought u.pou it. But the earliest 

 scientific recognition, recording, as far back as the writer knows, that these high gravel 

 ridges were regarded as lake beaches, was by DeWitt Clinton, who, in 1811, described 

 the ridges I'rom Lewiston to Rochester,- and by William Dewey,'' a civil engineer, who in 

 1836 proposed to locate upon it the Rome and Watertown Railroad. Many miles of the 

 railway were subseqirently constructed along its foot. 



In the " Greology of New York," published in 1812, Prof. James Hall describes the 

 ridge roads following the beach from Great Sodus Bay to Niagara River, and refers to his 

 having heard of this ridge extending around the end of the lake. He even ascertained 

 that the beach was not of uniform height, but he did not explain the variation by the 

 theory of the more recent warping of the earth's crust. In 1859, Mr. Sandford Fleming,' 

 described the spit south-west of Toronto, called " Davenport Ridge," and distinguished 

 that portion of the so-called ridge, which was of beach structure from the terraced shores. 

 In 1863, the Geological Survey of Canada suggested that the Davenport Ridge was 

 an eqitivaleut of the somewhat loAver ridge roads of New York. This happy hit, I have 

 more recently found to be correct. But elsewhere, on the northern side of the lake, 

 beaches occur at approximately the same heights, at distances apart, which of itself, in 

 this warped region, is usually proof of dissimilarity of age. The Canadian Survey did 

 not define the Bu.rlington Heights as a lake-beach, or identify its position. 



But the most important observations upon the old beach have recently l)een made 

 by Mr. Cr. K. Gilbert, in tracing and identifying as belonging to the same series its various 

 portions upon the southern and eastern sides of the lake. In doing so, he found that 



' A short abstract of this paper appeared in Science, Jan. IS88. 

 - Discourse before the N. Y. Historical Society, 1811, p. 68. 

 ' Dr. Hough quotes Wm. Dewey in History of Jefferson Co., N. Y. 

 * jCanadian Journal, Toronto, 1859. 



Sec. IV, 1889. 10. 



