100 



I'aised, The rocks of the district are quartzites overlain by mica-schists, 

 hox-nblen'de schists, gabhos and dipyr-diorites, which pass into one 

 another. The apatite veins occur only in the gabho and dipyr-diorite, 

 or in the immediate vicinity of these rocks, which, although contem- 

 poraneous with the other schists, are considered to have probably had 

 an eruptive origin. He believed the apatite to have been derived from 

 the gabho and dipyr-diorite, and deposited by water in clefts caused by 

 the contraction of the rock on 'cooling. The apatite • deposits of 

 Norway and Canada being so like one another in many lespects, it 

 might be supposed that when such a constant relation between the 

 apatite and gabho was found to exist in the former country, a similar 

 relation would obtain in the latter, but this was apparently not the case. 

 The dipyr-diorite had, however, lately been recognized by him among a 

 collection of rock fragments, from the vicinity of Arnprioi', sent to the 

 Survey for examination, and a description of it would shortly Ije 

 published. 



