lOO ROYAL SOCIETY OF CANADA 



series. This overlying limestone series first comes into view along the 

 road between Kingston and Gananoque, near what is known as Pitts 

 Ferry, and as the lowest beds of the limestone hold fossils which have 

 been determined as belonging to the Black Eiver formation, there is a 

 manifest gap in the regular sequence through the lack of deposition of 

 the Chazy shales and limestones. The Calciferous dolomites are also 

 practically absent in this place. 



At Barriefield opposite Kingston city, and for several miles to the 

 north along the shore of the St. Lawrence as well as on the roads in this 

 direction, and along the course of the Rideau canal northward, the sand- 

 stone itself is absent and the limestones of Black River age are the 

 lowest member of the Palseozoic series. In some places these are under- 

 laid by thin beds of arkose forming a marly deposit of a greenish-grey 

 colour, and holding small scattered pieces and coarse debris of the under- 

 lying reddish granite, and these beds pass upward directly into the lime- 

 stone portion. In places these marly beds contain fossils among which 

 a small orthoceratite is the most abundant, and in some layers these are 

 very numerous. In so far as these have been examined they represent 

 species which may possibly pertain to the Chazy, though the evidence 

 points rather to Black River forms. 



These contacts of the Black River limestones with the underlying 

 crystallines are at the same level as the contacts of the Potsdam sand- 

 stone elsewhere in the vicinity. The limestone formation of Barriefield 

 and of Kingston city extends northward along the canal for some miles 

 without any intervention of the sandstone. Occasionally the lower beds 

 hold fossils among which a Leperditia is probably the most plentiful, 

 and pieces of Tetradiuvi, apparently T. fihratum occur. 



In the southern part of Kingston city these limestones, which con- 

 tain hard and dolomitic fine grained beds resembling lithographic stone, 

 pass upward into massive limestones which abound in large fossils of 

 characteristic Black River age such as Stromatocerium rugosum, Colum- 

 naria Halli, Tetradium fihratum, Adinoceras Bigsbyi, etc., with other 

 forms which are found throughout the formation as developed in the 

 Ottawa basin. All the strata lie in a nearly horizontal position except 

 where deposition has occurred on a sloping rock surface such as a 

 rounded granite or other crystalline rock mass, when the strata conform 

 in dip with the slope of the underlying rock and sometimes present a 

 qua-quaversal structure. 



A similar arrangement of strata and formations is seen in the state 

 of New York, adjacent on the east side of the St. Lawrence river. Thus, 

 in the area east of that part of the river between Brockville and Pres- 

 cott, the Potsdam is succeeded upward by the Calciferous or Beekman- 



