L. V. Pirsson — Gi'ustal Warjping in Ontario. 25 



Art. III. — Crusted Warjnng in the Temagami-Temisha- 

 ining District^ Ontario / by L. Y. Pirsson.* 



The gradual rising of the great Ontarian shield, upon whose 

 southwestern flank the great lakes are being slowly tilted to 

 the southwestward, presents a geologic problem of primary 

 importance. We may reasonably expect that fuller knowledge 

 concerning it will tlirow much light on secular continental 

 movements. 



This tilting and the various phenomena to which it has given 

 rise have been the subjects of study by various geologists, par- 

 ticularly Gilbert and Taylor, whose results have been published 

 in a notable series of articles.. The latter has especially studied 

 the sequence of events arising along the noi'th shores of the 

 Great Lakes from their southward canting, and, in his paper on 

 the former Lake Algonquin stage of the lake system, he presents 

 a map upon which the node lines, or axes of tilting, are given. f 

 It is of great importance that this work should be carried to 

 the northward, and especially to the northeast, so that ulti- 

 mately the crest and extent of the rising shield may be deter- 

 mined. So far not much work in this direction has been 

 undertaken with this object in view, and in this brief paper 

 the writer desires to point out a region whose topographic 

 features appear to oflier much of interest and significance in 

 connection with this matter. His attention was first called to 

 it in the summer of 1907, on a visit to the mining region of 

 Cobalt, during which Lake Temagami was traversed and Lake 

 Temiskaming and the Ottawa valley descended. ISTo detailed 

 studies were carried out, but the observations made en route 

 on journeys lasting a couple of weeks in this area aroused his 

 interest in it, and this has been deepened by a study of what 

 has been written upon it, and especially by the excellent report 

 and geologic maps of Barlow;}: and of the Provincial geologists 

 on the mining district. The facts given in this article are 

 taken mostly from these sources, supplemented in a few cases 

 by original observations. 



Lahe Temiskaming . — This lake is nearly 70 miles long from 

 the point where the River des Quinzes enters it to the outlet 

 at the head of the Long Sault Rapids. While in the upper por- 

 tion it is several miles wide, this width soon diminishes and the 

 greater part of the lower portion is not over a mile broad, or 

 is even less ; in some stretches it is not wider than the Ottawa 

 River to which it gives rise. There is a difference of water 



* Abstract of a paper given before the Yale Geological Club, April, 1909. 

 \ F. B. Taylor, Amer. Geol., vol. xv, p. 116. 1895. 

 i Ann. Eep. Geol. Surv. of Can., vol. x, 1897, Eep. I. 



