CAPE BEETON ISLAND, NOVA SCOTIA. 517 



The following section at Irish Cove, East Bay, may serve to convey 

 a general idea of the character of these measures, and of the asso- 

 ciation of the felsites with the red and grey syenites : — 



ft. 



Greenish, white, and red laminated and granitoid felsite 480 



Greenish felsite and red syenite 100 



Bluish soft porphyry 85 



Purple and bluish laminated felsite 233 



Red syenite and reddish soft granitoid rock 247 



Greenish and reddish granitoid rocks, often nearly pure felspar 269 

 Felsite and syenite of variable composition, with veins of calcite 130 



Eed granitoid felsite, with diorite 160 



Similar alternations of red and greenish felsites and syenites 



make up a thickness of .. 3000 



Eed and grey syenite, coarse and fine 2333 



Similar measures, composed of alternations of felsites, syenites, 

 and aluminous nacreous shales, greenish and grey in colour, 

 make up a section not less than 8900 feet in thickness. 



At numerous points throughout the island these measures are cut 

 by dioritic dykes, some of which are as late as the Lower Carbo- 

 niferous, but they have not yet been described in any detail. 



Crystalline Limestone Sbeies. 



Unconformably resting on these strata, but agreeing with them 

 in their general development and position, is an interesting series of 

 felsites, syenites, diorites, mica-schist, quartzite, and quartzose con- 

 glomerate, interstratified with crystalline limestone and dolomite. 

 These measures are locally known as the George's Eiver Limestones 

 of St. Andrew's Channel, the locality in which they are typically 

 developed and were first referred to their true position. 



The alternation of the limestone with the gneissoid and related 

 rocks brings them into close connection with the felspathic group, 

 from which, however, they are apparently separated, owing to the 

 presence of red syenite and felsite pebbles in the lower conglo- 

 merates and by unconformability. Similarly the Lower Silurian 

 conglomerates of St. Andrew's Channel have received witnesses from 

 this limestone series. However conjectural any speculation may be 

 as to the age of these measures, it is certain that, as compared with 

 the metamorphic slates and quartzites of the Lower Cambrian auri- 

 ferous strata of Nova Scotia and the fossiliferous Lower Silurian of 

 St. Andrew's Channel, they mark a line equal to that observable 

 between the latter and the indurated Devonian and Carboniferous 

 of this island. 



The area occupied by this limestone series is limited in compa- 

 rison with that of the felsite group, but it was formerly, in all pro- 

 bability, of much greater extent, for it presents at several points 

 traces of having suffered severe denudation prior to the deposition 

 of the Lower Silurian strata ; and this is borne out by the thickness 

 of the George River section, viz. 6602 feet. 



In the northern district a narrow band stretches between Dundas 

 and Ingonish rivers. Excepting a small patch on Middle River, it 

 is not met with again until the head of Whyhogomah Bay is reached, 



Q.J.G.S. Ko. 168. 2n 



