91 



The Bonaventure formation. Beginning with the south 

 shore of Mai bay, is a great mantle of red conglomerates and 

 sandstones which covers all the coast regions from here 

 south over the whole Bay Chaleur region, save where it 

 has been torn away by sea and weather and left the under- 

 lying formations exposed. The name Bonaventure was 

 given by Logan and was taken from Bonaventure island 

 off the coast of Perce which is entirely constituted of these 

 conglomerates though they rise to greater heights in Mt. 

 Ste. Anne at Perce (1,200 feet). The formation is almost 

 horizontal throughout its extent, but the gentle undulations 

 of its northern portion are admirably expressed in the broad 

 rolling summit of Mt. Ste. Anne. This Bonaventure 

 formation is in part of distinctly continental origin but 

 its heavy conglomerates have doubtless been piled together 

 along a rough coast not unlike that which now faces the 

 Gulf. These conglomerates are in considerable measure 

 composed of blocks and boulders of the fossiliferous rocks 

 beneath, Cambrian to Devonian, and they are frequently 

 of enormous size, having in one instance a weight of 8 tons, 

 the angularity of this fragment indicating that it had 

 fallen from an overhanging sea cliff. The Bonaventure 

 formation is believed to represent the later stages of the 

 Devonian and the early stage of Carboniferous time, 

 indeed all of the latter that is recorded by deposits on the 

 peninsula. It is also the youngest rock formation in 

 Gaspe. By the early observers it was considered as 

 altogether of Carboniferous age and was correlated with 

 the red sandstones of Nova Scotia, Prince Edward Island 

 and the Magdalen islands which are now known to be of 

 Permian age. Ells was the first to recognize a distinction 

 in the composition of the conglomerates and thereupon 

 based a distinction in age, calling the lower or limestone con- 

 glomerates, Devonian, and the upper beds with fewer 

 lime and more crystalline pebbles, Carboniferous, a 

 difference not easy to recognize at many localities. 



The limestone conglomerates at the base are clearly 

 exposed at and about Perce, and the upper beds in the 

 summits of Perce mountain. In the outcrops on the Bay 

 Chaleur shore, this distinction is much obscured and the 

 red sandstones and conglomerates with jasper pebbles 

 lie everywhere on the upturned edges of the grey Silurians 

 often producing brilliant colour contrasts. The total 

 original thickness of these Bonaventure beds is not known. 



