HONEYMAN ON NUVA SCOTIAN GEOLOGY. 349 



of diorite from granitoid to crypto-crystalline is readily seen in the 

 bed and sides of a small stream which crosses the Railway at the 

 south end of Folly Lake, and also in Rocky Brook on the north 

 side of the same Lake. 



In this brook the diorites are intersected by numerous small 

 veins of red syenite. The red syenite, farther on, is seen to be 

 penetrated by dark green cypto-crystalline diorite, in veins. 



The sections between Jobe's and Higgin's Brooks are beautifully 

 variegated. There are crypto-crystalline diorites of various shades 

 of green with brown porphyries and bright red syenites. The 

 structural aspect of these rocks is sufficiently perplexing, while they 

 seem as a whole to be " indigenous" or metamorphic — some of the 

 crypto-crystalline diorites and the porphyries seem to be " exotic" 

 or io'neous. 



The gravel banks which obscure or partially cover the rocks of 

 this band, seem to merit more than a passing notice. The sections 

 on both sides of the Railway indicate the thickness and extent of 

 the accumulations of gravel. An examination of the material, e. g. 

 boulders, gravel and sand, shows that it is chiefly, if not wholly, 

 derived from the surround ino; rocks. • 



The extent of the accumulations, their breadth and depth, show 

 that the waste of rocks must have been very great. The roundness 

 of the material shows the amount of rollins; to which it had been 

 subjected, while its stratification indicates that water was the agency 

 eno:a2:ed in arrano-ino; the banks. 



The formation of the material may largely belong to a period or 

 periods anterior to the Post-pliocene, while its diminution and par- 

 tial transportation southwards was the work of the agencies of the 

 latter period. 



It is possible that prior to the Post-pliocene period. Folly Lake 

 occupied the greater part of the hollow that lies between the moun- 

 tains that rise on the east and west, that it extended to the north as 

 far as the carboniferous formation and was embanked by it, that it 

 rose to a higher level than at present, and received the waters, with 

 debris, of the streams that flow from the mountains on either side, 

 which are now known as Wallace River and its tributaries. At 

 this time the only outlet of the lake may have been Folly River 



