21 



The thickest section includes 36 feet of Don beds and 

 5 feet of peaty clay below water, with 85 feet of peaty clay 

 above water followed by 55 or 60 feet of stratified sand, 

 making in all 186 feet of interglacial beds. The general 

 section shown in the cliffs will be described first, and then 

 the fossils will be taken up. 



THE SCARBORO SECTION. 



At Victoria park, toward the east end of Toronto, the 

 flat sandy shore ends and boulder clay shows above the 

 water, standing up as a comparatively low cliff capped with 

 Iroquois sand beds. Toward the east the cliff rises and 

 becomes more complex in structure until it reaches a height 

 of 355 feet four miles from Victoria park, after which it 

 descends and finally reaches lake level at Highland creek, 

 9^2 miles from its commencement. This fine section shows 

 not only the greater part of the interglacial beds, but a 

 series of four tills with interbedded stratified sand and clay, 

 and also nearly 100 feet of Iroquois sands towards the 

 western end. The upper series of boulder clays and inter- 

 stratified beds is confined to a small part of the section at 

 its highest point. To the east and west of this only one 

 sheet of boulder clay can be seen, but it stretches almost 

 continuously along the upper part of the section, though 

 with great variations in thickness. 



It is evident that the interglacial beds were greatly 

 eroded by river action before the second ice advance, as 

 may be seen at the " Dutch Church," where a river valley 

 was cut to a depth of 166 feet, having a width of 1,200 

 feet at lake level and nearly a mile on top. The layer of 

 boulder clay, after rising to 150 feet, rapidly dips down 

 to the level of the lake at this point and then rises again 

 beyond it. This is in reality the second sheet of till in the 

 succession, the lowest one being 40 feet below the lake, 

 underlying the unio beds mentioned above. 



The waves of lake Ontario undercut the cliff, especially 

 in seasons of high water, after which slices slip down and 

 are removed by storms. Where there are several successive 

 years of low water in the lake much of the face of the cliffs 

 becomes covered with vegetation, though they are too ver- 

 tical in the neighborhood of the Dutch Church to permit 

 of much plant growth. The earliest reliable survey of Scar- 



