1 82 The Ottawa Naturalist. [January 



It has been crossed in four different places* viz., about a 

 mile east of the St. Francis River in the township of Cleveland ; 

 along- the west bank of the St. Francis, and also about three miles 

 further west, in the township of Melbourne ; and near Foster 

 Junction on the Canadian Pacific Railway in the county of Brome. 

 The last mentioned locality is about forty miles from the first, yet 

 the stratigraphical relations seem to be the same, it being the 

 most northwesterly member of the pre-Cambrian exposed along 

 the Sutton Mountain anticline. 



The economic importance of this rock is due to the copper 

 deposits which are contained in, or are associated with, it. As 

 far as it has been possible to ascertain, all the copper localities of 

 any known importance that are mentioned in the Report of the 

 Geological Survey of Canada for 1866 (pp. 310 — 314) in connection 

 with the rocks of the Sutton Mountain fold, occur in association 

 with this amygdaloidal trap. Amongst these are the St. Francis, 

 Balrath and Coldspring mine?, as well as others which have been 

 more or less minutely described (op. cit. pp. 38-39). From the 

 descriptions of other localities given in the Geology of Canada, 

 1863, (pp. 606-607) it appears that rocks of this type may have a 

 wide distribution in the Eastern Townships, especially in the 

 copper-bearing districts. 



The occurrence of similar rocks also of cupriferous f character 

 in the Appalachians of Pennsylvania**and elsewhere is well known, 

 and the separation of these from the sedimentary strata of the 

 Eastern Townships would be an important step towards a scientific 

 determination of the economic possibilities of this part of the pro- 

 vince, as well as towards a more detailed elucidation of its complex 

 geological structure than the progress of scientific investigation in 

 Canada has yet permitted. 



* The examination in Melbourne was made with the assistance of Mr. F, 

 W. Major of Bishop's CoHege, Lennoxville, and that at Foster by the aid of 

 Mr. H. A. Honeyman of Knowlton. 



**Bulletin U. S. Geol Survey, No. 136, pp. 25 — 27. " Ancient Volcanic 

 Rocks of South Mountain, Pennsylvania." F. Bascom. 



t The line of copper deposits in the State of Vermont, from Berkshire and 

 Richford along the boundary line southward as far as Waterbury, may also 

 indicate the extension of this rock to the south. Vide " Geology of Ver- 

 mont," 1861, pp. 850 et. seq., by Edward Hitchcock, and " The Report of the 

 State Geologist on the Mineral Resources of Vermont," 1899-1900 pp. 7 &: 12, 

 by G. H. Perkins. 



