140 Transactions of the Canadian Institute. [Vol. VII. 



Present Features. — General Description. 

 Pleistocene Deposits. 

 Eastern Rock-Valleys. 

 Jointed and Fissured Uplands. 

 Gorges and Valleys of the Niagara Cuesta. 

 Islands and Outliers. 

 Depth of Excavation. 

 Lowland Rock-Surface. 

 Summary. 



Pleistocene History. — A Summary. 

 RhXENT History. — A Summary. 



LITERATURE. 



INTRODUCTION. 



Location. — That portion of the Province of Ontario designated 

 Central Ontario is a triangular area with its base on Lake Ontario 

 to the south ; the western arm is formed by the Niagara escarpment in 

 its extension from Hamilton to Collingwood ; the northern boundary- 

 follows the edge of the crystalline rocks from Georgian Bay to a point 

 on the St. Lawrence river a short distance east of Kingston. 



Historical References and Sources of Information. — Previous to the 

 institution of the Geological Survey of Canada, in 1843, there had been 

 no systematic studies of the geology of Upper Canada, now the 

 Province of Ontario. Before that date much even of the then unsettled 

 parts of the Province had been surveyed into townships, and more or 

 less accurate maps prepared. Admiral Bayfield's surveys of the Great 

 Lakes were the most important work upon the shore-lines of the 

 Province. The present available maps, though in part corrected by 

 more recent work, are based largely upon these early surveys. Dr. J. J. 

 Bigsby had published (1829) a {q.\\ papers in which reference is made 

 to certain features of the area under discussion. After the institution of 

 the Survey, the most important work is that of Alexander Murray. 

 Between 1843 ^"cl 1856 Murray had explored and mapped a large 

 portion of the present Province. His work in 1843 in the western 

 portion of this area, and in 1852 in the eastern portion, forms the basis 

 of our present knowledge of its geology. The first systematic account, 

 in which all of Murray's work is summarized, was published by Sir 

 William Logan in 1863. This volume, entitled "The Geology of 



