o02 THE CANADIAN NATURALIST. [Vol. I. 



At a mucli lower level tlum the higher or medial portion of the 

 Artemesia gravel ridge which runs nearly north and south; there 

 is another ridge known as the " Oah Ridge,'' which leaves the 

 Silurian escarpment near Palgrave (on the H, & N. W. railway) 

 :it a height of 722 feet above Lake Ontario. It extends eastward 

 to near the " Great Bend '' of the Trent river, the summit of the 

 ran<re beina about twelve or fourteen miles north of the lake, 

 after passing eastward of Toronto. The Northern railway crosses 

 it at 754 feet, the Toronto and Xipissiug at 893 I'eet, Whitby 

 branch at 781 feet and the Midland railwa}' at GG5 feet above 

 Lake Ontario. It is from 200 to 800 feet above the broad 

 trough from Georgian bay to the Bay of Quinte, occupied by 

 Simcoe, Balsam, Rice and other lakes drained by Trent river. 

 The basin of this trough is underlaid by Palaeozoic and older 

 rocks. Several small lakes occur on this ridge without apparent 

 outlets. A spur of this ridge runs to Lake Ontario near Scar- 

 boro, and forms the "heights," rising 300 feet above the lake. 

 It consists principally of stratified fossiliferous clay and sand with 

 two intercalated beds of boulder-bearing clay. Portions of the 

 "Oak Ridge" eastward of the meridian of Toronto, consist of 

 clay ridges — probably the exposed equivalents of the clay beds of 

 •'Scarboro Heights." The highest portion of Oak ridge is only 

 300 feet above the rocky floor of the trough, which forms the 

 immediate northern margin. We are safe in concluding that 

 the stratified character of the lower portion of the ridge con- 

 tinues downward to the rocky floor on which it lies, or with no 

 important uns'tratified deposit beneath to constitute it a moraine. 



In studying these ridges, especially the Artemesia ridge, we 

 cannot fail to be struck with the similarity of those so-called 

 Kettle Moraines of Wisconsin, Coteau des Pairies and Coteau de 

 Missouri. There is a general parallelism between all these ranges. 

 Even a portion of the Artemesia gravel is nearly as elevated as 

 Coteau des Prairies. 



Other high terraces and beaches occur along the St. Lawrence 

 at 900 feet above the sea (Dawson); and in Labrador, at 1000 

 feet, besides erratics at much higher elevation (Hind). 



In Ireland and Wales marine beaches are found at from 1200 

 to 1400 feet above the sea. 



Origin of the Terraces. — As before pointed out, we have no 

 evidence of any general morainic character of the "Oak ridge." 

 On studying the levels of the country covered with Artemesia 



