424 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



At places, as south of the Robui beach at Perce, the lower beds are fine feldspathic red, green, 

 or gray sandstones, but even these carry pebbles, and the prevaihng character of the formation 

 is conglomeratic. South of tliis region under immediate consideration, sweeping along all 

 the country on the north shore of Chalours Bay and into New Brunswick, these deposits are 

 widespread. 



It is by no means easy, with present knowledge, to determine the true age of these deposits. 

 In considering the commonly accepted view of Logan and his successors expressed above, we 

 are confronted by phenomena at Perce and thence north to Point St. Peter, which seem to us to 

 render this conclusion less secure than the observation of the more southerly outcrops would 

 induce. Strata of conglomerates composed of pebbles carrying Siluric and Devonic fossils from 

 the beds beneath and included by Logan in the Gaspe sandstone group, are found at various 

 inchnations from CMen Blanc, on Gaspe Bay, all the way around Malbay to the Grande Coupe 

 at Perce; at places these beds are nearly horizontal; from Cannes de Roche to Corner of the 

 Beach, on the south shore of Malbay, they are nearly vertical and their color varies from red to 

 ashen gray. In hthologic composition, the nature of the component pebbles, and in the general 

 aspect of this northern series there is no distinction from that comprising Perce Mountain and 

 Bonaventure Island. This latter, the typical expression and section of the Bonaventure con- 

 glomerates, stands with abrupt and sheer escarpments on the east and north, teUing, like the 

 Catskills, of a widespread further extension. The stratigraphic distinction between these higher 

 Bonaventure conglomerates and the lower conglomerates of ]\Ialbay is only the apparent uncon- 

 formity between the two. The gently sloping higher mass of Perce Mountain seems to he 

 directly on the vertical conglomerates of Canne de Roche, and it is the indication of this sharp 

 unconformity that has been regarded as evidence of the distinction in age in the two parts of this 

 great homogeneous mass of conglomerates. My examination of the sea waU from the MuraiUes 

 at Perce to Corner of the Beach leads me to the impression that the erect conglomerates at the 

 latter place, cut off as they are, to a narrow shore belt by the Siluric hmestones behind, have been 

 downthrown from their normal position along the zone of great disturbance which has involved 

 the MuraUles, Cape Barre, the sea floor outside the North Beach, and Perce Rock. No fact 

 impresses the casual observer more forcibly than the apparent presence of extensive uncon- 

 formity between these Bonaventure beds and the lower conglomerates, but the appearance is, I 

 am confident, illusive and the Bonaventure conglomerates seem to represent a southern slightly 

 undulated part of the same conglomerate mantle which appears more highly faulted in the 

 antichnes farther north. Such an interruption involves several important conceptions. 



1. These conglomerates were certainly laid down unconformably on the vertical edges of 

 the Devonic and Siluric strata about Perce. 



2. As the Gaspe sandstones of the Gaspe Basin have been folded up together with the 

 Devonic hmestones of the Forillon, either the Gaspe sandstones of the north are older than the 

 entire series of conglomerates or the folding at the south, which involves the Devonic limestones 

 and the SUuric strata together, was earlier than the upturning of the Devonic hmestones at the 

 north with which the older strata were not involved ; or both conclusions are probable. 



3. While the sandstones constituting the lower part of the "Gaspe sandstone series" and 

 their presence in the higher beds are indicative of barachois or lagoon conditions, the conglom- 

 erates themselves are clearly open coast deposits formed under such circumstances as prevail 

 to-day wherever these very rocks are exposed to the play of the sea. 



4. That the Bonaventure conglomerates of this typical section, either in whole or in part, 

 are of Carbonic age is probably only in a sense that their formation began in late Devonic time 

 and continued without effectual interruption into that of the subsequent era, in the same sense 

 perhaps as the upper beds of the CatskiU group of New York seem to be of a post-Devonic age. 



These strata constitute the latest of the rock deposits in Gaspe. 



