103 



" With the ordinary type, Jbowever, there occur at two points to 

 the north-east of St. Stephen, rocks of very ditferent aspect. These 

 are the dark grey dioritic rocks containing serpentine, diallage and 

 chromic oxyd. About two miles north of St. Stephen, may be seen 

 ledges of coarse grained, dark grey granitoid diorite, having thin layers 

 of picrolite or fibrous serpentine in the joints as well as serpentinous 

 matter in the body of the rock. In crossing these ledges towards St. 

 Stephen, the rock becomes somewhat darker, and portions are met with 

 exhibiting thin lamination, the laminae being separated by layers of 

 serpentine about one-eighth of an inch in thickness." There seems to 

 be some doubt as to the age of these serpentinous rocks, and although 

 supposed to be of Laurentian age, they are here plaoed under the head 

 of Huronian rocks. The presence of chromic oxyd in them and the 

 want of crj'stalline limestone in their association with other rocks give 

 them cjuite a different character to those of the Laurentian series of 

 this Province. The first outcrops of these serpentines which we know 

 of, in a north-westward direction from these last mentioned are on 

 Lake Abittibi where they are found to be associated with micaceous , 

 hornblendic, and chloritic schists, fine grained hard quartzites, diorites 

 and dioritic schists, A little island in this lake is composed of strongly 

 magnetic serpentine with splintery fracture, resinous lustre and 

 weathering dull white. An analysis of it was made by Dr. Harrington 

 who found it to contain grains of chromic iron and a very small quantity 

 of nickel besides silica, alumina, protoxyd of iron and magnesia. 



According to Dr. Bell there is, in the middle of Pigeon Lake, and 

 at about one mile from the lower end of it, a small island composed of 

 very dark green serpentine, with strings of calcspar and crysotile. It 

 weathers rusty, and Dr. Harrington, on analysis, found it to contain 

 oxyd of chromium, both in the form of small grains and in chemical 

 combination with the rest of the rock. 



No mineral of economic importance has yet been found in these 

 serpentines, but perhaps when the country where they are more abund- 

 antly met with is settled, some wandering geologist or hard-working 

 habitant will discover in them large deposits of asbestos or other valu- 

 able mineral. 



