RANGE AND EXTENT. 473 



This rock is frequently remarkable for the numerous and complicated contortions which its layers exhibit, 

 often rivalling in this respect any other rock in the State. Sometimes these irregularities appear to be in- 

 creased by the passage of granite veins through the rock. Nos. T & 7 and T$T in the Cabinet, are specimens 

 of contorted hornblende schist from Peru. 



Range, Extent and Thickness. 



There are several belts of hornblende schist in Vermont, six of which are represented 

 upon the Geological Map, Plate I. Two of them are in calciferous mica schist, two in 

 gneiss, and two in talcose schist. 



A small range in gneiss, which is not represented upon the map, is in Vernon, being 

 the northern prolongation of quite a large band of hornblende schist in Bernardston, Gill 

 and Northfield, Mass. It is found only in the southeast part of the town. 



The largest band of hornblende schist is in Brattleboro and Guilford, extending from 

 Massachusetts. It forms an anticlinal axis resting directly upon gneiss. Its relations 

 may be discovered by examining its position upon Sections I. and II, and the Massachusetts 

 Section at Shelburne Falls. It is seen in all these cases to overlie the gneiss, and under- 

 lie the mica schist. It more properly belongs to the gneiss, than the mica schist. In 

 Massachusetts some of this belt approaches hornblendic gneiss ; in Vermont it is often pure 

 hornblende, an exceedingly tough black rock. 



The other range of hornblende schist in the calciferous mica schist group extends from 

 Holland to Greensboro, passing through the towns of Charlestown, Salem, Brownington, 

 Barton and Glover. This range is described by Rev. S. R. Hall as interstratified with 

 mica schist and silicious limestone. It varies in width from a few rods to two or three 

 miles. It probably extends to Cabot. 



So much hornblende exists in the gneiss in Marlboro and Newfane, that we represent 

 two bands of hornblende schist in these towns upon the map ; one upon the west and the 

 other upon the east side of the formation. The rock is mostly true hornblende schist, but 

 it is interstratified with hornblendic gneiss. The western of these ranges may. extend from 

 Halifax to Townshend, and may possibly connect with another range in Windham. It 

 lies west of the porphyritic hornblende at Williamsville ; yet it probably belongs to the 

 same belt of rock, upon opposite sides of an anticlinal axis. The same anticlinal appears 

 at Fayetteville. The hornblende schist west of Fayetteville is remarkable slaty, and it is 

 of great width. A large amount of the hornblende schist shows itself between Williams- 

 ville and the Newfane bed of steatite and serpentine. Local beds of hornblende schist in 

 the gneiss in the south part of the State are specified in the descriptions of the general 

 sections ; and their character may be learned from the nature of the specimens in the State 

 Cabinet illustrating them. 



The most southern band of hornblende schist is located in the extreme west part of 

 Marlboro, capping a hill west of the Methodist Church. This is of two kinds the thick- 

 bedded rock containing beautiful garnets, and the thin-bedded, or slaty variety. The 

 irregularities in the dip of this belt are remarkable, especially upon Section II, to 

 which we refer for the facts. The other band of hornblende schist is in Windham. It 

 lies between the gneiss and talcose schist. Section IV. crosses it. It is developed 

 between Pierce's bed of steatite and Whitman's bed of serpentine, and is about seventy- 

 five rods wide. Its length is unknown to us. 

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