58 The Ottawa Naturalist. [May 



REVIEWS. 

 The Physical Features and Geology of the Paleozoic Basin 



BETWEEN the LoWER OtTAWA AND St. LaWRENCE RiVERS. 



By R. W. Ells, LL.D. (Trans. R. S. C, Sec. IV, 1900, 

 pp. 99-120.) 



This paper may be looked upon as a continuation of one read 

 before the Royal Society in 1894, in which many additional facts 

 relating- to the structural features of the Palaeozoic formations 

 exposed in what may be called the Ottawa Basin. This infor 

 mation is believed to be especially important and opportune at the 

 present time, in view of the boring operation which have lately 

 been undertaken for the purpose of securing- a supply of natura' 

 gas and oil which would be economically valuable. The formations 

 exposed range in age from the Potsdam sandstone which rests 

 upon the uneven surface of the Archsan to the Medina shales 

 which here represent the lowest member of the Silurian proper. 

 These constitute in general a broad synclinal basin whose bound- 

 aries are defined and note- is made of their extension across the St. 

 Lawrence into the state of New York. The various railways 

 traversing and giving access to this area are mentioned as well as 

 certain details in regard to the elevation above sea level at certain 

 points. These have been secured through the kindness of Mr. 

 Jas. White, Geographer to the Department of the Interior from 

 advance proofs of "Altitudes in the Dominion of Canada," 

 which it is expected, will be published shortly. These levels have 

 evidently been quoted only approximately and many of them will 

 be corrected in Mr. White's forthcoming volume. The determin- 

 ation of the various lines of demarcation between the several 

 formations is very difficult owing to the thick and widespread cover- 

 ing of drift. A few general remarks are made in regard to ice 

 movement, the strice representative of these showing no less than 

 three such periods. The thickness of the several formations vary 

 considerably at different points and the presence of numerous 

 extensive faults prevents any very definite statement. 



The following estimates are furnished and will doubtless be 

 found valuable in any future boring operations which may be 

 undertaken. The figures represent what is believed to be the 

 g^reatest thickness. 



