Review of History of the Great Lakes. — Spencer. 295 
lakes to rise and flood their southern and western ends, since 
the modern lakes were established. The quantitative charac- 
ter of this change will be explained in the next paragraph, 
and the effects upon the modern drainage beyond. 
9. Deserted Beaches in the Lake Region and their Deforma- 
tion. The Laurentian lake region abounds with the remains 
of deserted beaches, terraces, sea-cliffs, and other evidences of 
former shore lines. The writer has made an extensive sur- 
vey of these phenomena in Canada, across Michigan, in 
the Adirondacks, and in the Green and White moun- 
tains.* Mr. G. K. Gilbert did the first systematic work 
south of lakes Ontario and Erie.f Mr. F. B. Taylor has 
more recently extended the surveys north of lake Michigan 
and northeast of lake Huron ; + and Dr. A. C. Lawson, 
north of lake Superior. £ There has been very little systematic 
work in the lake region upon these problems except by the 
named observers. Some of these old shore lines, after form- 
ing highways known as ridge roads, have been surveyed for 
hundreds of miles; others are broken or interrupted. Gener- 
ally speaking, the northeastern extensions are unknown, owing 
to the want of surveys; to the changes in the topography, 
rendering their surveys difficult; to our ignorance of the phe- 
nomena; to our ignorance of suspected modern faults; and to 
our further ignorance as to how much the phenomena are ob- 
*"Notes upon the Origin and History of the Greal Lakes," cited be- 
fore; "Deformation of the Iroquois Beach and Birth of Lake Ontario." 
Am. .lour. Sci., III. vol. xr.. 1890, pp. 443-451; "Deformation of tin- Al- 
gonquin Beach and Birth of Lake Huron." id., vol. xr.r. 1891, pp. 12- 
"21: "High Level Shores in tin- Region of the Great Lakes and their 
Deformation," id., pp. 201-211; "Deformation of the Lundy Beach and 
Birth of Lake Erie," id., vol. sxvn, 1894, pp. 207-212; "The Iroquois Shore 
north of the Adirondacks." Bulletin, Geol. Soc. Am., vol. in. 1891, pp. 
188-491 . Each of these papers, excepting the one last cited, is accompan- 
ied with a map. 
(■"The History nf Niagara River," Sixth Annual ReporJ ■ >!' the Com- 
missioners of the State Reservation at Niagara, for the year 1889, pp. 
61-84, with eight plates falso in the Smithsonian Annual Report for 
1890); Proe. A. A. A. s.. vol. xxxv. for 1886, pp. 222, 223. 
; "Reconnaissances of the Abandoned Shore Lines of Green Bay and 
of the South Coast of Lake Superior," American Geologist, vol. xnr. 
pp. 316-327, and 365-383, May and June, 1894; "The Ancient strait at 
Nipissing," Bulletin, Geol. Soc. Am., vol. v. pp. 620-626. Each nf these 
papers has a map. 
§ "Sketch of the Coastal Topography of the North Side of Lake Su- 
perior, with special reference i<> the Abandoned Strands of Lake War- 
ren," Twentieth Annual Report, Geol. Surv! Minnesota, for 1891, pp. 
181-289, with map and profiles. 
