3o6 The American Geologist. November, looi. 
THE TORONTO AND SCARBORO' DRIFT SER4ES. 
By Warren Upham, St. Paul, Minn. 
Among all the North American localities of interg-lacial 
deposits, Toronto and Sc'arboro", situated close together on 
the northwestern shore of lake Ontario, present questions of 
the greatest interest and importance in their relation to the 
changes of clinnate attending the decline and end of the Ice 
age. The coniplex drift series of these localities, including 
alternate formations of till and fossiliferous freshwater beds, 
has been described, with discussion of their climatic signifi- 
cance, by Hinde,* Coleman,t Chamberlin,$ and the present 
writer. § 
It will be needful, therefore, to give in this paper only a 
general statement 'of the drift sections and their remains of 
the Late Glacial fauna and flora. The chief purpose will be 
to inquire what these imply concerning the conditions that 
here permitted several alternations of glacial and interglacial 
beds, and to learn whether they indicate a far retreat of the 
border of the ice-sheet, worthy to be called a distinc^t inter- 
glacial epoch, or were records of m'oderate oscillations of the 
ice border, being then referable wholly to minor stages in the 
closing Champlain epoch of our continental glaciation. 
According to the view presented by Chamberlin, in 1894, 
the Toronto^ interglacial beds are referred provisionally to a 
long interval between the lowan and Wisconsin stages or 
epochs, giving to them a large epochal significance. They 
would thus denote a prolonged timie of greatly diminished 
area of the cbntinental ice^sheet, or its complete disappear- 
ance, succeeded by renewed far advance, if not indeed wholly 
ntew accumulation, of the vast ice-ifields. Hinde, writing 
much earlier, gave a nearly equivalent opinion ; and Coleman, 
*G. J. Hinde, "The Glacial and Interglacial Strata of Scarhoro' Heights and 
other localities near Toronto, Ontario," Canadian Journal, vol. xv, pp. 388- 
413, April. 1877. 
fA. P. Coleman. "Interglacial Fossils from the Don Valley, Toronto," 
American Geologist, vol. xiii, pp. 85-95, Feb., 1894.; "Glacial and Inter- 
glacial Deposits near Toronto. "yourwa/ of Geology, vol. iii, pp. 622-645, Sept.- 
Oct., 1895; "Glacial and Interglacial Beds near Toronto, "/our. of Geo/., vol. 
ix, pp. 285-310, May-June, 1901. 
JT. C. Chamberlin, "The Toronto Fossiliferous Beds," in chapters contri- 
buted to Prof. James Geikie's Great Ice Age, third edition, 1894, pp. 765-769 ; 
"The Classification of American Glacial Deposits, "/our. o/" Geo/., vol. iii, pp. 
270-277, April-May, 1895. 
§"Ctimatic Conditions shown by North American Interglacial Deposits," 
Am. Geologist, vol. xv, pp. 273-295, with map. May, 1895. 
