EASTERN EANGE. 467 



gneiss. A careful examination reveals several minor variations of this synclinal axis, as 

 seen in the enlargement of a part of Section V, on Plate XVI. 



The calciferous mica schist divides this middle range of gneiss into two parts as far 

 south as Chester. It has been traced only into the north part of the town, but may be 

 found to extend further, by careful examination. It is a very narrow strip south of 

 Proctorsville, occupying the Proctorsville Gulf, which owes its origin probably to the 

 softer nature of the rock. A very narrow belt of gneiss extends from the west part of 

 Chester, through Cavendish (passing through Proctorsville) , Reading west part, and the 

 east part of Bridgewater, into Barnard. A large amount of hornblende schist is associa- 

 ted with this belt of gneiss. The other part of the gneiss we have traced into the north 

 part of Reading. Its prolongation to the Otta Quechee River, is given upon the 

 authority of Prof. Adams. He found a deposit of gneiss in Hartford and Hartland, 

 which was isolated from all other rocks. The middle ranges of gneiss he thought 

 extended no further north than Chester. As we have carried the middle range of gneiss 

 to the south line of Hartland, it seems very probable that the two deposits form parts of 

 one great whole, and we have so represented them upon the map. We suppose that this 

 projection of the gneiss to Hartford forms an anticlinal axis, underlying the calciferous 

 mica schist. 



EASTERN DEPOSITS OF GNEISS. 



There are three patches of gneiss upon or near Connecticut River in Vermont. One of 

 them is of small width, and exposed to view at the surface in Brattleboro and Gruildford, 

 but is not of sufficient width to be represented upon the map. Upon the Massachusetts 

 Section (Plate XV), the same range appears as gneiss underlying hornblende schist at 

 Shelburne Falls. It is exposed by erosion. As erosion has not worn away the overlying 

 rocks north of Shelburne, the gneiss is not seen till we arrive in the north part of 

 Guilford. Upon Section I. the same anticlinal will be noticed, but the erosion has not 

 penetrated through the hornblende schist. Upon Section II. the hornblende schist is 

 fully worn through, and towards half a mile's width of subjacent gneiss appears. This 

 gneiss is rather obscure. Part of it is properly a garnetiferous mica schist. This band 

 is not seen again in Vermont, unless it be in a metamorphic condition in the granite of 

 Black Mountain in Dummerston, and the immense mass of granite in Orange, etc. This 

 granite occupies the same stratigraphical relations to the mica schist, as the gneiss of 

 West Brattleboro. 



The gneiss in Vernon and at Bellows Falls on Connecticut River, has a different aspect, 

 is stratigraphically higher, and is probably of a different age from the gneiss just 

 described. The first patch of gneiss that we shall mention is not found out of Vernon, in 

 Vermont ; but it extends into Massachusetts on the south, and into New Hampshire on the 

 cast. At the extreme southeast corner of the town, with the gneiss are associated mica 

 and hornblende schist. (See Fig. 321.) Further northwest the gneiss becomes thick- 

 bedded, compact and jointed ; and is scarcely different from granite, or at times from 

 syenite. There is a belt of mica schist running from South Vernon depot into Ber- 

 nardston, which forms a part of the group. This band of gneiss curves very much in 

 conformity with the bend in Connecticut River, though not precisely. A narrow belt 



