58 THE CANADIAN NATURALIST. [Vol. viii. 



from 600 to £00 feet above the lake, and is more generally covered 

 with iceberg drift deposits. The intervening valley with various 

 rivulets is often very picturesque, having on one hide the bolder 

 bills pierced with deep gorges, while on the other there is 

 the moulded contour of the higher southern range. In many 

 places the bids enclose pretty lakelets, while an occasional peak 

 towers to a considerable height above the range. Here and 

 there, throughout the " H.ippy Valley," active mining villages, 

 and the remains of those long since descued, are to be seen side 

 by side. 



The Copper Bearing Series forms a bro.-id belt to the west of 

 Lake Superior extending from Fond du L ac to Thunder Bay. 

 A Inge portion of Isle Koyale is made up of the rocks of this 

 formation. 



According to Professor Robert Bell, of the Canadian Geo- 

 logical Survey, the Copper- Bearing Series of rocks on the North 

 Shore is most largely developed in Nipigon Basin, including 

 Black Sturgeon River, and the shores of Nipigon, Black and 

 Thunder Bays. The deposits in this region extend for 170 

 miles northward from Lake Superior, and the greatest breadth 

 is about 80 miles. Lake Nipigon is situated in the eastern 

 portion of this basin. Owing to this wide distribution Professor 

 Bell has proposed the name Nipigon Series for this peculiar 

 geological formation, it being more suitable than the old provi- 

 sional name of Upper Copper Bearing Series. These rocks arc 

 described by Sir William Logan, and Mr. Macfariane, and more 

 fully in the recent reports of Professor Bell to Mr. Selwyn, the 

 Director of the Canadian Geological Survey. 



The same rocks occur in patches eastward of Nipigon Buy, and 

 also on Michipicoten and other islands. It is probable that 

 when this wide-spread region is better known, many localities 

 will hd found to be of as much economic value as those rich 

 mineral deposits on the south shore of the Lake. 



b. — Lithological Structure. — Lithologically the copper-bear- 

 ing series of rocks is peculiar, and consists of alternate beds of 

 igneous ;.nd sedimentary deposits, the iormer j redominating. 

 Dioritcs. melaphyres (altered trappean rocks j and amygdaloid^ 

 iorm the group of igneous rocks, and sandstones, conglomerates. 

 and tome argillaceous scams niuke up the group of sedimentary 



