464 GNEISS. 



association with it of numerous beds of limestone and hornblende schist. At Cuttings- 

 ville there is a large mass of granite in the gneiss. The granite has a peculiar character, 

 and needs a chemical examination. Some of the specimens effervesce with acids, 

 showing the presence in it of a carbonate. There is scarcely any mica in it, and the 

 feldspar predominates at the expense of the quartz. It tarnishes much upon exposure. 

 In a gorge two miles south of Cuttingsville the gneiss is less distinct. In Shrewsbury, 

 east and southeast of Cuttingsville, the gneiss is syenitic. 



The pyrites at Cuttingsville apparently is in a bed, being interstratified with the 

 associated rocks. Beneath the pyrites there is a bed of hornblendic gneiss twenty feet 

 thick. The rock capping the bed is an impure limestone, containing concretions of calcite 

 resembling fossils. There is a hornblende dike at the west end of the bed, lying between 

 the ore and the limestone. This dike runs with the ore, and rests upon it over a distance 

 of five rods. The whole length of the bed of pyrit-ps is one-fourth of a mile. There 

 seems to be an anticlinal axis in the middle of the bed. The dip of the adjacent rock 

 varies from horizontal to perpendicular. 



The single anticlinal shows itself in the section across Mount Holly, and is illustrated 

 both in Section V, Plate XVI, and Fig. 18. The mountain at Mount Holly is lower than 

 at any point in the State south of Winooski River. The strata upon the west side of this 

 anticlinal are often perpendicular, and may even dip east at some localities. Near Mount 

 Holly station there may be seen subordinate curves in the strata, which will illustrate the 

 character of an inverted anticlinal axis. Near the east line of Mount Holly, on the road 

 to Plymouth, the strata dip about 50 E. 



Most of the gneiss in Menclon is concealed by drift, as also in Sherburno upon the route 

 of Section VI. The top of Pico Peak is made up of rather obscure gneiss, with a small 

 easterly dip. It is difficult to learn much about the position of the gneiss upon this 

 mountain, because the ledges are almost entirely concealed from view. The bed of azoic 

 limestone in the north part of Mendon is remarkably large for a bed in gneiss. The 

 greater part of Chittenden is made up of this range. The only ledges we could find were 

 at South Chittenden, and along the west border of the formation north of this village. 

 The gneiss here contains many pebbles of feldspar, and of other rocks also appearing por- 

 phyritic. It is distinctly mica schist in a gulf north of South Chittenden. The gneiss 

 forms very high mountains in the east part of Chittenden, which we have never 

 explored. 



The belt of gneiss rapidly narrows in Chittenden, and at Goshen it is narrower than at 

 any other point south of Hazen's Notch. This narrowing of the gneiss seems to be con- 

 nected with the topography of the northeast part of Chittenden and Pittsfield. Most of 

 the rock of this belt in Goshen is gneissoid rather than true gneiss. It occupies the lower 

 part of the high mountains, Mt. Horrid and others being capped by talcose schist. It is 

 much wider in Hancock and Ripton, and the whole mountain range here is composed of 

 gneiss, without any cap of talcose schist. There arc traces of a westerly dip near the top 

 of the mountain, on the west side of Flint's tavern. From Hancock village to Ripton 

 village the rock is gneissoid. 



We have not examined the character of the gneiss of the Green Mountains between 

 Hancock and the top of Camel's Hump, but suppose it to be the peculiarly character- 

 ized rock over this area that it is generally north of Goshen. 



