IO 



succession in Eastern Canada was to be obtained, it would 

 be necessary to select some large area of these rocks and 

 map it in much greater detail than had hitherto been 

 attempted, the examinations in the field being supple- 

 mented by thorough petrographical study of the various 

 rock types represented in the area. The area selected 

 for such detailed study was that designated as Sheet 

 No. 118 (Haliburton sheet) of the Ontario series of 

 geological maps which are being issued by the Geological 

 Survey of Canada. As will be seen by the accompanying 

 sketch map, this district lies close to the margin of the 

 great Northern Protaxis, north of Lake Ontario and to 

 the east of Georgian bay. 



Dr. Frank D. Adams, with whom Dr. Alfred E. Barlow 

 was subsequently associated, undertook for the Geological 

 Survey a detailed geological study of this region, con- 

 cerning the geological structure of which nothing was 

 known at that time but which, from its position, promised 

 to yield valuable results if carefully studied. During 

 the progress of this work it became evident, if the sub- 

 stantial results expected were to be realized, that the 

 work should be extended to cover the district lying to 

 the south-east of the Haliburton sheet. This was accord- 

 ingly done and two maps were prepared; one, the Hali- 

 burton sheet, on a scale of four miles to an inch (2-53 km. 

 per cm.), and the other, embracing the south-eastern 

 portion of the Haliburton sheet and the district lying 

 to the south-east, on a scale of two miles to an inch, (1 -27 

 km. per cm.), which was designated as the Bancroft sheet. 

 The Haliburton map-sheet embraces an area of 3,45ft 

 square miles (8,600 sq. km.); the Bancroft map-sheet 

 1,955 square miles (4,900 sq. km.); and the two map- 

 sheets together cover 4,200 square miles (10,500 sq. km.) 

 The field and accompanying laboratory work occupied 

 a period of about eight years, the results being embodied 

 in Memoir No. 6 issued by the Geological Survey of 

 Canada in 1910. [1.]. 



PHYSICAL FEATURES OF THE AREA. 



The general character of the surface of the area is 

 uniform throughout its entire extent. The country is 

 a great uneven plain which may be called a peneplain, 



