REVIEWS 501 



4. Scarboro peaty clays, cold-temperate climate with trees and mosses, and 70 

 species of extinct beetles, formed as a delta by Laurentian River in interglacial 

 Scarboro Bay. 



5. Scarboro stratified sand with some trees and freshwater shells of cold-temperate 

 climate, delta completed; lake stood 152 feet above the present. 



6. Water drawn off by lowering of outlet, subaerial erosion of previous beds, and 

 cutting of river valleys more than 150 feet deep. 



7. Advance of Wisconsin ice-front raising the water to about 160 feet, as shown 

 by stratified interglacial clay, retreat for 50 miles and readvance, followed by two later 

 retreats and advances, the water finally rising 360 feet above the present lake. 



8. Final retreat of ice-sheet followed by water levels of lakes Warren and Iroquois, 

 and a brief entry of the Gulf of St. Lawrence into the Ontario basin, which, however, 

 remained fresh. 



The reviewer questions whether the lowan drift is well represented or even present 

 at this locality, since the interval shown by the interglacial beds appears to be much 

 greater than observations in the region where lowan and Wisconsin drift sheets are 

 well displayed would lead one to expect. This does not invalidate in any way the 

 conclusions announced in this paper ; it simply suggests that the lower till sheet may 

 be Illinoian. 



Coleman, A. P. Duration of the Toronto Interglacial Periods. Am. Geo!., 

 Vol. XXIX, pp. 71-79, 1902. 



In reply to a paper by Upham which had appeared in the American Geologist, 

 Coleman estimates the time required for the processes which took place between the 

 two advances of the ice. Of this time 1,300 years is considered a low estimate for 

 laying down the interglacial beds and 2,500 years for trenching them ; it is considered 

 probable that the time should be more than doubled. The warm-climate flora is shown 

 to be inconsistent with the view that the ice-sheet was near by. The author holds it 

 probable that the ice had disappeared as completely from Canada in that interglacial 

 period as at the present time, which perhaps is embraced in another interglacial period. 



Coleman, A. P. Relation of Changes of Levels to hiterglacial Periods. 

 Geol. Mag., Dec. 4, Vol. IX, pp. 59-62, 1901. 



It is thought there was an uplift to the northeast, followed by a depression. The 

 uplift would render Labrador cooler and help start an ice accumulation, and this in 

 turn would tend to depress the region. The melting of the last ice-sheet would allow 

 the land to rise again. It is a problem whether this elevation to the northeast would 

 be sufficient of itself to cause glaciation. 



CuRRiE, P. W. On the Ancient Drainage at Niagara Falls. Trans. Can, 

 Inst.. Vol. VII, pp. 7-14, 6 pis., 1901. 

 (Not examined.) 



DowLiNG, D. B. Physical Geography of Red River Valley. Ottawa Nat., 

 Vol. XV, pp. 115-20, 1901. 



The geological history is sketched, and with it the development of the main 

 physical features. The effect of glaciation and of the occupancy by the Glacial Lake 

 Agassiz form the closing part of the discussion. 



