TRANSACTIONS 



OF THE 



|l0e ^tatim Institute of ^tmut. 



SESSIOI^f OF 1891-92. 



i. — xo'j'es ok co^x'retionary structure in various rock 

 Formations in Canada. — By T. C. Weston, of the Geo- 

 logical Survey of Canada.* 



(liend Nov. 9th, JS91.) 



Many times between the years 1860-70 the late Sir Win. E. 

 Logan, and subsequently Dr. Selwyn, called my attention to 

 certain concretionary forms found in the gold-bearing rocks of 

 Nova Scotia. Some of these seemed to be organic, and I was 

 requested to make and examine microscopic sections of them. 

 In treating several of these with acid, they proved to be com- 

 posed chiefly of dolomite, with a large proportion of siliceous 

 matter, and generally a little iron pyrites, which formed a 

 nucleus. 



In 1890 a number of similar forms were found by Mr. Willis 

 in the rocks of the Northup Gold mines, Rawdon, Nova Scotia. 

 They were handed to Professor Hind, who supposed them to be 

 fossils, and assigned them to Lower Silurian age. Wishing the 

 "judgment of a specialist," he gave them to Professor Kennedy, 

 of King's College, who confirmed Professor Hind's opinion and 

 pronounced the fossils to be Stromatopora. Mr. Fletcher and Mr. 

 Faribault, of the Geological Survey, while in the vicinity 



* Communicated by permission of the Director of the Geological Survey of Canada. 



