402 THE CARBONIFEROUS SYSTEM. 



largest lake, properly so called, in Cape Breton. To the eastward of 

 this lake, a spur from the metamorphic country to the northward 

 separates this part of the district from the Lower Carboniferous country 

 of the county of Victoria. At the extremity of this spur, on the 

 border of Whykokomagh Basin, the Lower Carboniferous conglomer- 

 ate with syenitic pebbles forms a hill named the Salt Mountain. On 

 this conglomerate rest thick beds of laminated limestone, from which 

 rise unusually copious springs, some of them of pure water, others said 

 to be salt or brackish. At Middle River, we again find the Lower 

 Carboniferous limestone with several of its characteristic fossil shells ; 

 and from this place, as far as St Ann's Harbour and the Big Bras d'Or, 

 the whole of the low country consists of sandstone, shale, and conglom- 

 erate, with limestone and gypsum appearing in several places. A 

 lofty ridge of syenitic rocks separates St Ann's from the Bras d'Or, 

 and at its extremity, Cape Dauphin, there is a patch of Carboniferous 

 rocks which have been described in detail by Mr Brown in the Pro- 

 ceedings of the Geological Society. Mr Brown gives the following 

 section, which is interesting as illustrating the arrangement of the 

 several members of the series in this part of Cape Breton. The order 

 is descending, and the beds dip S. 80° E. at an angle of 58°. 



Lower Coal measures, seen about half a mile from Cape Dauphin — a 



few fossil plants — thickness not stated. 

 Fine grained and pebbly sandstones (millstone-grit) — fossil 



plants .... r, ... . 200 ft. 



Finely laminated gray shales with thin bands of limestone 110 



Slaty sandstones with traces of plants .... 10 



Blue and gray shales with thin beds of nodular limestone 120 



Strong sparry limestone ...... 6 



Soft crumbling marls ....... 90 



Strong limestone ....... 18 



Brown sandstone ....... 12 



Red shales ........ 33 



Blue shales ........ 8 



Strong limestone — lower beds laminated — fossil shells 



Productus cora^ Encrinus . . . . . . 17 



Mottled red and green marls ..... 24 



Litermingled sandstones and limestone ... 22 



Blue shale ........ 6 



Red shale 8 



Carry forward 684 ft. 



