84 THE CAMBRIAN. 



the beds are very frequent,* and there is no proof that these are less 

 ancient than the conformable veins or "leads." Though occurring 

 in the Quartzite division, the auriferous veins usually follow bands of 

 slaty rock included in the quartzite, a circumstance which much 

 favours their profitable working. 



In my Acadian Geology, I associated with the Atlantic coast 

 series the extensive deposits of mica slate and micaceous gneiss 

 found in the peninsula ending in Cape Causo, and also very exten- 

 sively in the west, more especially in Shelburne County. I also 

 regarded all the true granite of this district as intrusive, and on 

 the evidence of the fossiliferous rocks cut by it on the Nictaux River, 

 as of later date than the Oriskany period. It has, however, lately 

 been customary to regard much of the granite as gneiss, and to 

 speak of this and the associated schistose rocks as Laurentian and 

 Huronian. Aware that many new exposures had been made in 

 recent years by mining and roadmaking, and being desirous to 

 satisfy myself as to whether any change was required, I revisited 

 the district around Sherbrooke and the St Mary's River, and was 

 so fortunate as to find what seems to me conclusive evidence of the 

 correctness of my former views. 



Eastward of Sherbrooke, the beds of the Gold series run endwise 

 against the great mass of granite rock extending from near the St 

 Mary's River beyond Indian Harbour, and given in my Acadian 

 Geology as a typical illustration of intrusive granite. -J- At a place 

 near the Upper Indian Harbour Lake I found the granite and 

 quartzite in contact, the line of junction running about south-east, 

 and the quartzite dipping north-east at an angle of 70°. At the 

 junction the quartzite is slightly changed in character, having 

 apparently minute hornblende and mica crystals developed in it ; but 

 the granite sends numerous veins into the quartzite, and in these 

 becomes coarser in texture, and presents beautiful aggregations of 

 plumose mica. This is, I believe, the character of the junction 

 everywhere, except that where the slaty bands approach the granite, 

 they are more altered than the quartzite. (See Frontispiece.) 



At Cochrane's Hill, near the forks of the St Mary's River, a new 

 gold mine has been opened on quartz veins said to be richer in 

 visible gold than usual, and included in beds which must belong to 

 the upper part of the Quartzite series. These beds lie, however, in 

 the line of the great intrusive granite belt extending from Cape 

 Canso along the south side of Chedabucto Bay, and they are penc- 



* 1 have observed and sketched examples of this at (Jniacke and Sherbrooke. 

 f Tage 019, and plate, p. 013. 



