Section IV., 1903 [ 97 ] Trans. R. S. C. 



III. — Notes on some Interesting rock-contacts in the Kingston 

 District, Ont. 



By E. W. Ells, LL.D. 



(Read May 19th, 1903.) 



In a former paper before this society the writer described in some 

 detail the relations and distribution of the Potsdam and Calciferous 

 formations of the Ottawa and St. Lawrence basins. It was there pointed 

 ont that no stratigraphical break occurred between the two, but that the 

 Potsdam sandstone division, as developed in Canada, represented merely 

 the downward extension, through transition beds, of the Calciferous 

 division in which the rocks are to a large extent dolomitie, into sand- 

 stones and conglomerates in which calcareous matter is practically absent. 



Since that date much detailed work has been done by the Geological 

 Survey in the area bounded by the St. Lawrence, Ottawa and Rideau 

 rivers, and the extension of the latter water-way southward along the 

 line of the Rideau canal to Kingston. The rocks which surround the 

 Archœan axis which extends across the St. Lawrence river from Ontario 

 into the state of New York, crossing that river between Brockville 

 and Kingston, have been mapped over a large area. 



The distribution of several of the lower members of the Palœozoivî 

 series in this district is somewhat irregular. Thus on the eastern side 

 of the Archœan axis the several formations, from the basal beds of the 

 Potsdam to the top of the Lorraine, succeed each other with great regu- 

 larity, except where their normal position is disturbed locally through 

 the agency of faults, while on the south side several important gaps 

 occur, owing to local peculiarities of deposition, so that the actual 

 sequence of formations there seen is quite different from that found on 

 the north side of the axis. 



The rocks of this Archaean axis consist of granites, granite-gneiss, 

 crystalline limestone, quartzite, etc., which are similar to those of the 

 Grenville series north of the Ottawa river, and are undoul)tedly the con- 

 tinuation of this series to the south-west, both in eastern Ontario and in 

 the northern portion of the state of New York east of the St. Lawrence. 

 The granites occur sometimes as large masses and sometimes as dykes 

 and are generally reddish in colour. They cut all the rocks of the 

 Grenville series proper, and are, therefore, regarded as of later date. In 

 the intermediate basin of the Ottawa these rocks were eroded prior to 

 the deposition of the Palaeozoic sediments, so that there is a wide valley 



