SOUTH WESTERN NOVA SCOTIA. POWERS. 299 



and quite numerous. The peculiarity of the rock hereabouts 

 is the abundance of large patches of chlorite three to four 

 inches in diameter, with rounded or quadrangular outlines. 

 They have probably been formed as a replacement of horn- 

 blende, but no trace of the original mineral was discovered. 

 A thin section of the rock from one of the islands shows a 

 fine groundmass of quartz and sericite in which are large 

 metacrysts of staurolite which enclose numerous quartz 

 grains, large crystals of biotite which enclose small grains of 

 quartz and titanite, metacrysts of garnet, some pennine and 

 small amounts of iron ore and apatite. The strike of the 

 rocks is due E-W with a dip of 20 S. The same staurolite 

 schist continues around Baccaro Point, but quartzite appears 

 on the Barrington Bay shore a mile west of Port LaTour. 



IGNEOUS ROCKS 



Micaceous granitic rocks occupy the central part of the 

 peninsula of Nova Scotia, smaller masses appearing in numer- 

 ous places from Halifax northeastward to Cape Canso, and 

 also south of the main area. Two of the latter enter the area 

 under consideration, at Shelburne and at Barrington. These 

 batholiths consist respectively of biotite-muscovite granite 

 and of quartz (biotite) diorite, with some pink aplitic 

 granite in the immediate vicinity of Barrington. 



The age of these granites is Middle Devonian; they cut 

 the fossiliferous Lower Devonian slates of Clementsvale and 

 of Torbrook-Nicteau, and the arkose derived from the wea- 

 thering of these granites at Horton Bluff is found abundantly 

 in the Horton Series which is of basal Mississippian age 

 (Pocono, according to David White). The granites were intruded 

 at the time of the Middle Devonian revolution which folded 

 the Canadian Appalachian geosyncline and the region now 

 embraced in the Maritime Provinces. The folding was not 

 completed at the time of the intrusion of the granite because 

 the latter shows the effect of a moderate amount of shearing. 



