266 



Eiometres ^^^ Boisdalc ridgc and after leaving the area of 

 the Carboniferous Limestone series, it crosses 

 Pre-Cambrian granite which extends westward 

 beyond George River station. 



i6-6 m George River Station — Alt. 37 ft. (11-3 m.). 



26-7 km. 



GEORGE RIVER.* 



(G. A. Young.) 



INTRODUCTION. 



The line of the Intercolonial railway eastward and 

 southward from George River station affords an opportunity 

 of examining a part of a section transverse to the axis of 

 the Boisdale hills at the northern end of this upland. 

 This range of hills is largely underlain by Pre-Cambrian 

 and Cambrian strata with detached areas of Carboniferous 

 measures outcropping along their flanks. 



The Boisdale hills follow a S.W.-N.E. course for a 

 distance of about 30 miles (48 km.) and vary in width 

 from 6 miles (9-6 km.) in the southern portion to about 

 I mile (2-4 km.) at the northern end. Along their 

 northwestern side, the hills rise steeply, in places abruptly, 

 from the waters of Bras d'Or lake, to heights of 600 feet 

 (180 m.) to 900 feet (275 m.) above sea level. Along 

 their southeastern side, the hills in the north are bounded 

 by the lowlands of the Sydney Carboniferous basin, while 

 towards the south they rise directly from the shores of 

 East bay, a northeasterly extension of Bras d'Or lake. 



The strata outcropping in the Boisdale hills have been 

 mapped and grouped by Fletcher [1] as follows:^ 



r^ u •( f Carboniferous Limestone series. 



Carboniierous /^ 1 -r r- 1 



[Carbomterous Conglomerate series. 



[Cambrian. 



T3 r- u -r Pre-Cambrian, George River series. 



rre-Carbomierous { o r- u • -^ • u- ^- 



I Pre-Cambnan, granite, gneiss, schist, 



1 etc. 



*See Map — George River Station. 



