GEOLOGY OF THE PHILIPSBURG REGION OF QUEBEC 315 



The complexity induced by a complicated system of close folding 

 and overthrust faulting has paved the way for varying interpreta- 

 tions of structure, while a dearth of fossils has resulted in erroneous 

 correlations based mainly on lithological similarities and an insufh- 

 cient study of what few fossil remains have been obtained. The 

 writer spent eleven weeks in this area during the summer of 1922. 

 This time was largely devoted to a thorough search of all available 

 and likely outcrops for fossils. The great bulk of the rock was 

 barren, but determinable fossils were found at seven different 

 horizons; at one in great abundance. Several new forms were 

 discovered and will be described at a later date. It has been thought 

 advisable to present in some detail the structural and lithological 

 peculiarities of the strata in this region, because in some cases the 

 correlations suggested in this paper must rest largely on inorganic 

 evidence. Since the proof or disproof of a widespread Ozarkian 

 system must rest on the complete understanding of such sections 

 as that of the Philipsburg region, such a detailed presentation seems 

 justified. The purpose of this paper is to present a summary of the 

 evidence, from field and faunal studies, that no Ozarkian rocks 

 are present in this area; that no great diastrophic or faunal breaks, 

 which are the accepted basis for the separation of geological systems, 

 occur in the northeastern part of the Champlain Valley. If the 

 correlations suggested here survive the test of detailed study in 

 other regions to the west and southwest of Lake Champlain, it must 

 follow that not only at Philipsburg, but throughout the Champlain 

 VaUey, deposition was not interrupted by any great break until 

 the end of Beekmantown times. 



STRUCTURAL RELATIONSHIPS IN THE PHILIPSBURG SERIES 



The rocks of the Philipsburg series occupy a position in northern 

 Vermont and southern Quebec between the east shore of Mississ- 

 quoi Bay and the valley of the Rock River, two miles to the east 

 (Fig. i). Their southern extremity can be seen in an outcrop 

 along the line of the Vermont Central Railroad about 500 yards 

 northeast of the mouth of Rock River, Vermont. The strike here 

 is N. 28° E. Following this direction southwestwardly across the 

 lowland of the Rock River, we next find rocks of a different char- 



