THE GKEAT CENTEAL SYNCLINE. 227 



by a fault which the exposures did not permit me to demonstrate. This 

 continues north into Shutesbury, where the whole series is cut by a trans- 

 verse fault, along which trap has been erupted in several places. North of 

 this point the series seems to be a regular overturned syncline. The bed 

 above the amphibolite (d) appearing in the center is a thin-bedded quartz- 

 ite (b) with few coarse muscovite scales, but it soon runs out, as does the 

 amphibolite, while a narrow band of the coarse muscovite-schist (e) runs a 

 long- way north, past the mineral springs and far into Wendell. 



Followed south the three beds ah'eady described soon dip beneath a 

 dark mica-schist containing much biotite and, at school No. 6 in Enfield, 

 many small needles of dark-brown tourmaline and a little feldspar. This 

 I have refen-ed to the Conway schist (/). 



This series runs S. 15° E., and so abuts with very acute angle upon 

 the fault which runs along the east side of the valley of Swift River Branch. 

 It is, if my interpretation as given upon the map be true, a syncline over- 

 turned to the west, and to the south of the transverse fault near the north 

 line of Pelham is further affected by a longitudinal fault which eliminates 

 part of the east flank of the fold. 



THE GREAT CEXTBAL SITNCLINE. 



This enters the State from New Hampshire, occupying the whole east- 

 ern half of the town of Warwick and extending eastward into Royalston a 

 mile beyond the limits of the area shown on the map (PI. XXXIV). 



West of TuUyville, in the apex of the town of Orange, it divides, 

 sending off an eastern branch (see p. 234), and itself extends south with 

 diminished width. 



WARWICK AND ORANGE. 



The tvestern quartzites and amphihoUtes. — For a long distance south the 

 syncline consists of a broad area of inica-schists, having on either side a nar- 

 row border of the quartzite beds (b) below, which separate the schists from 

 the Mousou gneiss on the east and on the west. Where they enter the State 

 in the eastern hillside above Sunny Valley, in the northern part of Warwick, 

 the basal bed is a white, shining muscovite-quartzite, often gneissoid, and 

 south of Warwick village it is a coarse, gneissoid quartzite, containing much 

 chlorite and magnetite. 



