i86 The Ottawa Naturalist. [January 



The Utica is this direction appears to constitute a con- 

 tinuous basin for more than fifty miles which apparently extends 

 to within a short distance of Vankleek Hill,occupying the valley 

 of the South Nation for some distance and being underlain by 

 the Trenton limestones which thence continue northward in 

 the direction of the Ottawa. The width of the Utica shales in 

 some portion of this area is not far from twelve miles and they 

 are in turn overlain by the Lorraine shales and sandy beds, 

 which in turn pass upward into the soft red shales of the Medina, 

 so conspicuous in the townships of Osgoode and Russell and in 

 the south-west part of Cumberland. Several minor undulations 

 affect the strata of the several formations in this part of the dis- 

 trict, but none of these have apparently resulted in greatly dis- 

 turbing the beds, with the exception of the great fault between 

 the Calciferous and the Utica. There are other faults visible in 

 the northern portion of the Palaeozoic basin, notably to the 

 south of L'Original, where there is a break between the Chazy 

 and the Black River or Trenton but this cannot be of great 

 magnitude since both these formations are comparatively thin. 



The foregoing will pretty well represent the distribution of 

 the principal rock formations in the immediate vicinity of Ot- 

 tawa, and in the extension of the basin to the east and west for 

 some miles. It may be remarked that they are all readily re- 

 cognized by their characteristic fossils, and large collections 

 have been made from time to time, from many localities, both 

 by the officers of the Geological Survey as also by several ob- 

 servers who are interested in the study of the geology of the 

 district. 



No attempt will be made in this paper to describe the 

 glacial and post-glacial deposits of the area. These have al- 

 ready been discussed at some length by different members of 

 the club, and large lists of the marine fauna, so abundant in the 

 clays and gravels, have been published in the Club's Tran- 

 sactions. 



