164 NEW YORK STATE MUSEUM 



is either not there clearly presented or is presented here with some 

 change of faunal association. It is not, in our view, a section of the 

 series there lost by faulting out, but the expression of the later Siluric 

 beds there, with a variant geographic association of species. 



Relations of limestone masses about Perce. We have, estimated 

 roughly the thickness of the masses here discussed as follows : 



Perce beds, 250 feet at Perce rock but probably rising 



in red peak to 400 feet 



Lost interval between Perce rock and Mt Joli (Cap 



Barre beds) 100-200 feet 



Mt Joli massive 700 feet 



Cap Canon massive ' 630 feet 



Limekiln massive 200 feet 



2030-2130 feet 



Thus there is a development of approximately 2000 feet of lime- 

 stones representing the geologic series from early Siluric (Black 

 River-Trenton) to well into the early Devonic or Oriskany. The 

 Cap Blanc massive with a thickness of 700 to 1000 feet is not in our 

 judgment an addition to, but a repetition of a part of the series. The 

 rocks on the Murailles are likewise regarded as not adding to, but 

 repeating the series in part, with the exception of the Cap Barre 

 beds which are partially provided for in the rock interval 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 ( ?) Limekiln beds 



Cap Barre beds Mt Joli (south flank) 



Mt Joli (north flank) Cap Canon 



Some doubt will attach to the proper position of the strata of the 

 Limekiln for the reasons already stated. 



With the foregoing succession we deduce a profound displacement 

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

 beds of Cap Barre for a thickness of 100 or more feet were squeezed 

 out, and their remnant overturned to their present place and atti- 

 tude, a quarter mile away, and their dip reversed. 



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