74 NEW YORK STATE MUSEUM 



ing the shore at any point and leaving only a narrow strip of much disturbed 

 conglomerates to constitute the southern sea wall of the bay. The west- 

 ward extent of these limestones is not known and their outcrops in the 

 mountains have not proved to be fossiliferous. Their relations to the 

 adjoining strata however, indicate in some measure the very great disloca- 

 tions which have affected this region. 



Relations of limestone and shale masses about Perce. The thickness of 

 the masses here discussed may be approximately stated as follows : 

 Perce beds, 250-300 feet at Perce rock but probably rising 



in Red peak to -.-.... . 500 feet 



Lost interval between Perce rock and Mt Joli (Cape Barre 



beds) - - 100-200 feet 



Mt Joli massive --- - 700 feet 



Cape Canon massive - - - - - - - 630 feet 



1730-2030 feet 



Thus there is a development of approximately 2000 feet of limestones 

 and shales representing the geologic series from early Siluric (Chazy-Tren- 

 ton) to well into the early Devonic. The Cape Blanc massive with a thick- 

 ness of 700 to 1000 feet is probably to be regarded not as an addition to, but 

 in greater part at least a repetition of a portion of the series. The rocks on 

 the Murailles do not add to, but repeat the series in part, with the exception 

 of the Cape Barre beds which are partially provided for in the rock inter- 

 val between Mt Joli and the Perce rock. In order of succession from the 

 top downward, we should from present evidence arrange the masses thus : 



Perce beds 1 t^ • 



Cape Barre beds j 



Mt Joli (north flank) beds ] 



Mt Joli (south flank) beds J. Siluric 



Cape Canon beds 



Faults. With the foregoing succession we deduce a profound displace- 

 ment between the Perce rock and the north face of Mt Joli by which the 



