NOVA SCOTIA 559 



of a new geological formation, the same that we have studied in pre- 

 ceding chapters. The structure of Cape Porcupine is represented in 

 Fig. 195. 



Fig. 195. — Arrangement of Syenite, Slate, and Conglomerate at Cape Forcupim. 



c b a, o 



(a) Syenite. (6) Slate. (c) Conglomerate and Sandstone. 



At Cape Porcupine the altered rocks of the group now under con- 

 sideration occupy less than three miles of the coast section, and are 

 separated by Carboniferous rocks and by Chedabucto Bay from the 

 eastern extremity of the older metamorphic district of the Atlantic 

 coast, distant about twenty-four miles. As Cape Porcupine affords 

 no fossils, and can therefore tell nothing of the condition of the earth 

 and its inhabitants at the time when these slates were deposited, we 

 may proceed to trace the continuation of its rocks into the interior. 



From Cape Porcupine, the southern margin of the metamorphic rocks 

 extends along the northern side of the Carboniferous district of Guys- 

 borough for about sixty miles, when it meets the Lower Silurian rocks 

 of the coast. In several places along this line, igneous action appears 

 to have continued or to have recurred as late at least as the Coal 

 formation period. This is testified by the condition of the Lower 

 Carboniferous rocks in many places near Gnysborough, westward of 

 which place a considerable promontory of altered and igneous rocks 

 extends to the southward, nearly across the Carboniferous district. 



The northern margin of tlie band, commencing at Cape Porcupine, 

 may be traced to the westward about forty miles, when it unites with 

 a broader but very irregular promontory of similar rocks extending 

 toward Cape St George. Between these two bands is included the 

 Carboniferous district of Sydney County. The tract formed by their 

 union is the widest extension of these rocks in the province. 



The metamorphic promontory extending to Cape St George, and 

 including the Antigonish and Merigomish Hills, attains a greater 

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

 tremity, however, it becomes divided into a number of detaclied liills 

 and ridges, separated by Lower Carboniferous beds, to which in some 

 cases the metamorphic action has extended itself. The Antigonish 

 and Merigomish Hills contain large masses of syenite, porphyry, 

 compact felspar, and greenstone, associated with slates and quartzite.* 

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



* Quartzite is a flinty rock produced liy the liardeniDg and alteration of sandstone. 



