1850.] DAWSON METAMORPHIC ROCKS OF NOVA SCOTIA. 351 



hypogene rocks. For our present purpose this group may be named 

 the syenitic group of metamorphie rocks. 



The most eastern point at which this group appears is Cape Por- 

 cupine in the Strait of Canseau, which presents a nucleus of reddish 

 syenite, against which rest hard dark-coloured slates, apparently 

 closely united to, and passing into, the syenitic mass. Cape Porcu- 

 pine is separated from the eastern extremity of the granitic belt about 

 twenty-four miles distant, by a tract of carboniferous rocks and the 

 waters of Chedabucto Bay. 



From Cape Porcupine, the southern margin of the syenitic group 

 extends along the northern side of the carboniferous valley already 

 referred to, for about sixty miles, with a course of S. 70° W. It 

 then meets, and apparently unites with, the northern margin of the 

 granitic group. At Cape Porcupine, the hypogene and metamorphie 

 rocks occupy only three miles of the coast section, and attain an eleva- 

 tion of 500 feet. Westward of that point, they extend in a narrow, 

 and perhaps in some places interrupted band, bounded on each side 

 by carboniferous rocks for about forty miles, when they unite with 

 a broader but very irregular promontory of similar rocks, extending 

 toward Cape St. George. The triangular space intervening between 

 these two metamorphie bands is occupied by carboniferous rocks. 



The metamorphie promontory extending to Cape St. George, and 

 including the Antigonish and Merigomish hills, attains a greater ele- 

 vation than the band connected with Cape Porcupine. At its ex- 

 tremity, however, it becomes di\ided into a number of detached hills 

 and ridges, separated by lower carboniferous beds, to which in some 

 cases the metamorphie action has extended itself. The Antigonish 

 and Merigomish hills contain large masses of syenite, porphyry, com- 

 pact felspar, and greenstone, associated with slates and quartzite. On 

 their western side near Arisaig, there is a patch of shale, slate, and 

 thin-bedded limestone, with Silurian fossils. 



The northern boundary of the broad band of metamorphie and 

 hypogene rocks, formed by the union of the two promontories already 

 noticed, extends in a westerly direction along the south side of the 

 Pictou carboniferous district, until it reaches the east side of the East 

 E/iver of Pictou, when it suddenly bends to the south, allowing the 

 carboniferous strata to extend far up the valley of that river. Here, 

 as at Arisaig, its margin includes a patch of fossihferous slates and 

 shales, among which is a thick bed of iron ore including fossil shells. 

 A few of the fossils of these beds are stated by Sir C. Lyell to agree 

 specifically with those of the Hamilton group of the United States 

 geologists. Prof. Hall of Albany, to whom I have sent a small col- 

 lection of these fossils, chiefly from Arisaig, where most of the species 

 are the same with those of the East River, is of opinion that they be- 

 long to the age of the Hamilton and Chemung groups. 



Immediately on the east of the East River, the metamorphie band is 

 about fifteen miles in breadth, and includes masses and dykes of syenite 

 and greenstone, and beds of quartzite and slate, the latter of very 

 various colour and texture. Beyond the East River, the metamorphie 

 band again widens ; and between the upper part of the Middle River 

 of Pictou and that of the west branch of the St. Mary's River (the 



