GEOLOGY OF THE TORONTO REGION 



The leaves and wood belong to more than thirty 

 species, which include Asimina triloba, Carya alba, 

 Chamaecyparis sphaeroidea, Crataegus punctata, 

 Juniperus virginiana, Madura aurantiaca, Platanus 

 occidentalis, Prunus, Robinia pseudo-acacia, Taxus 

 canadensis, Thuja occidentalis, Tilia americana, and 

 several species of ash, poplar, oak and elm, and two 

 extinct species of maple. The whole assemblage of 

 trees indicates a climate decidedly warmer than 

 Toronto at present, about like that of Ohio or Penn- 

 sylvania. 



The section at Scarborough Heights, some miles 

 east of Toronto on the shore of Lake Ontario, 

 includes 36 feet of sandy beds with unios and wood 

 beneath the water level, 90 feet of peaty stratified 

 clay, and 55 or 60 feet of stratified sand. The peaty 

 clay encloses a little wood, fragments of leaves, 

 mosses and seventy-two species of beetles, of which 

 only two still live. The stratified sand contains 

 wood and a few small shells. The fossils are con- 

 sidered to indicate a climate somewhat cooler than 

 the present, like that of Lake Superior, for example. 



The Scarborough beds are evidently delta deposits 

 laid down in a lake rising 150 feet higher than Lake 

 Ontario. Later the lake was drained and valleys 

 were cut in the delta by rivers, as may be seen at a 

 striking bit of cliff architecture called the " Dutch 

 Church." This is carved by rain and stream ero- 

 sion from boulder clay which filled the old valley 

 during the second ice advance. 





