NOTES ON THE GEOLOGY OF THE GULF OF 

 ST LAWRENCE 



BY JOHN M. CLARKE 



As Opportunity has afforded during the summer months the writer 

 has continued his observations on the geology, principally of the 

 Paleozoic formations, lying about and within the Gulf of St Law- 

 rence. Not all the notes and records made are yet properly digested 

 and fitted into their sequence in the geological history of this region, 

 but there are some which extend and fortify my earlier researches 

 and others w^iich illuminate the investigations of earlier workers 

 in these fields. The more tangible of these records are here brought 

 together as an expression of progressing knowledge which it may 

 be hoped will eventually give us a clearer conception of the develop- 

 ment of this interesting region and of the causes producing the 

 gulf itself. 



THE RELATIONS OF THE PALEOZOIC TERRANES IN THE VICINITY 



OF PERCE 



Perce is a region of boundless geological variety and interest. 

 The writer feels that he has, in previous publications, only intimated 

 its history, the details of much of which must be left to future 

 students of the region, particularly that part of it lying back of 

 the coast mountains. But in order to portray in panorama the 

 relations of the Paleozoics here represented in a way that may help 

 to clarify the situation, in the accompanying sketch a liberty has 

 been taken with this irregular coast line by stretching out all its 

 angles, headlands and bays into a straight line, so that, regardless 

 of the unavoidable distortion involved, the eye may grasp not only 

 the attitude of the rocks but their relative history. This section, 

 which will be taken as only an approximation to accuracy of ex- 

 pression and whose discrepancies are freely avowed because of 

 stretching a right angle into a straight line, is about six miles in 

 length, unequally foreshortened at the north end, and extends from 

 near Cannes des Roches at the north to the vicinity of I'Anse au 

 Beaufils at the south. The point of view is out to sea east of 

 Bonaventure Island, from the edge of the 50-fathom line which 

 along this stretch of coast makes a deep bay inward toward this 

 island (see Hydrographic map, p. 14, N. Y. State Mus. Mem. 9. 



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