USEFUL MINERALS. 587 



quartzite and slate of the hills, as well as of the Carboniferous beds of 

 the lower ground. This section, as far as the base of the hills, is 

 described in Chapter XV. The lowest Carboniferous bed is a thick, 

 coarse, gray and brownish conglomerate, dipping S. 20° W. It rests 

 unconformably on a bed of slate very similar to that seen in a like 

 position at the Great Village River, and which differs considerably in 

 appearance from most of the slates of these hills. The strike of the 

 slate is S. 70° W. ; and that of the bedding and slaty structure appear 

 to correspond. In a layer of graywacke included in this slate I ob- 

 served small and well-rounded pebbles of light-coloured quartz. This 

 slate is succeeded by thick beds of gray quartzite and hard olivaceous 

 slates. These occupy the river section for about 700 yards, or as far 

 as the " Falls," where the river is thrown over a ridge of quartzite 

 fifty-five feet in height ; a small rill pouring in on the eastern side 

 from a much greater elevation. Between the conglomerate and the 

 waterfall the quartzite contains a few narrow strings of ankcrite, and 

 (vt the fall there is a group of reticulating veins, some of them six 

 inches in thickness. They contain a little iron pyrites. These are 

 the only indications of the iron vein observed in this section ; and as 

 the group of beds in which it should occur is well exposed, it is 

 probable that it is represented here only by these small veinlets 

 distributed over a great breadth of rock. Above the fall the quartzite 

 and slate continue to alternate for a considerable distance, the dip 

 being generally to the southward, in one place at as low an angle as 

 55°. About a quarter of a mile above the fall they are traversed by 

 a dike or mass of fine-grained hornblendic igneous rock. 



On the elevated ground east of the Folly River the vein is again 

 largely developed, and two excavations exposed a part of its thickness 

 on the property of the Londonderry Mining Company. The excava- 

 tion nearest to the river shoAved a thickness of 190 feet of rock on the 

 south side of the vein. This consists of gray quartzite, olive slate, 

 and about three feet of black slate. These beds are traversed by a 

 few small strings of ankcrite, Avhich increase in dimensions on ap- 

 proaching the broken and irregular wall of the vein. About seventeen 

 feet of the south side of the vein consist principally of ankcrite. 

 Adjoining this on the north is red iron ore, with nests of specular 

 ore, veins and blocks of ankcrite decomposed in part to yellow ochre, 

 and fragments of rock. Ten feet in thickness of this red ore were seen 

 without exposing the north wall of the vein. 



On the surface in this vicinity are large fragments of brown hema- 

 tite, which mark the course of the vein. In the eastern excavation, 

 this mineral was seen in place near the surface and occupying fissures 



