26 THE ROYAL SOCIETY OF CANADA 



sequent to its glaciation until all the former products of the glaciation 

 had been carried out of the drainage basins and a prolonged era of 

 subaereal weathering of bedrock had set in and to accomplish this 

 would require more time than the whole period assigned to the 

 Pleistocene. 



Glaciation and Tertiary erosions have almost destroyed the 

 Lower Cretaceous formation in northern Ontario, leaving only 

 vestiges of it like the deposits under consideration. 



The view has hitherto been held that no pre-Glacial rocks later 

 than Upper Devonian were ever laid down in northern Ontario; 

 therefore the discovery of Mesozoic rocks and possibly of Tertiary 

 adds a new chapter to the geology of that province. 



Previous History 



The first notice we have of these deposits was recorded by Dr. 

 Robert Bell. The locality given was Coal brook, a small tributary 

 of Missinaibi river, and the material exposed was a 3-foot bed of 

 lignite, underlain by sticky blue clay, and overlain by late glacial 

 drift.i 



In 1880 Mr. E. B. Borron discovered an extensive deposit of 

 white sand and clay on the east side of Missinaibi river, about 5 miles 

 below the mouth of Coal brook.- 



In 1882 Mr. Borron found an outcrop of what he called yellow 

 ochre with some fine white clay on the eastern bank of Mattagami 

 river, about a quarter of a mile below the north end of Long Portage. 

 This is the outcrop from which Mr. McCarthy obtained the samples 

 he sent to the Mines Branch in 1918. 



During the same journey Mr. Borron saw a thin seam of lignite 

 on Mattagami river, about 5 miles below Long Portage. These two 

 localities are given on page 30 of his report for 1882. 



In 1890 Mr. Borron went out, equipped with apparatus, for the 

 purpose of testing the lignite seams discovered by Dr. Bell and 

 himself on Missinaibi river. 



He devoted most of his attention to borings on the lignite out- 

 crop on Coal brook. A plan of a portion of Coal brook, with the 

 positions and numbers of the holes bored, is given in his report. ^ 



Mr. Borron recognized the fact that the clays at this point were 

 quite distinct from the widespread glacial clays of the region, and 



1 Geol. Sur. Can. Rep. Prog., 1877-1878, p. 4C. 



- Report by E. B. Borron on Part of the Basin of Hudson Bay, Toronto 



2 Report on the Basin of Moose River, E. B. Borron, Toronto, 1890, pp. 65 to 69. 



