372 B. K. Emerson — " Bernard ston Series" of 



and is then brought up by a fault along the eastern base of the 

 schist series, and in places thrust over the latter in apparent 

 conformity. The fault line must be an exceedingly tortuous 

 one, and on the east the Grass Hill series must be a repetition 

 of the West Northfield series. 



The Bemardston Series east of the Connecticut. — The 

 adjoining area east of the river in Northfield, is unfortunately 

 so covered by the terrace sands, that only few outcrops appear. 

 I think that the rocks of the JBernardston series find their east- 

 ern limit through the whole length of ISTorthfield, Ewing and 

 Montague, at the foot of the high ground which bounds the 

 Connecticut Valley on the east ; that it ends without any 

 marked shore deposit ; but with great crushing of the fine 

 quartzite, probably on a fault of great magnitude and extent, 

 and finally that the quartzite schists and amphibolite, which 

 succeed to the east in the Northfield Hills, though presenting 

 some points of similarity with the Bernardston rocks, are to be 

 associated rather with the series which lies west of the argillite 

 and which are presumably older. 



The Quartzite in Northfield. — North of this village, a por- 

 phyritic quartzite identical with the eastern band in the West 

 Northfield range, crops out along the eastern edge of the high 

 terrace, but is immediately followed on the east by an older 

 series mentioned above. It is much brecciated and abundantly 

 cemented by hematite. It appears also in the brook bottoms ; 

 and just over the line in Winchester, a shaft has been sunk a 

 hundred feet in it for lead, which appears very sparingly in 

 narrow interrupted fissures of a few millimeters width, asso- 

 ciated with barite and fluorite in equally small quantities, and 

 at the bottom with beautiful druses of pale yellow, saddle- 

 shaped, dolomite crystals. Below the surface the quartzite is 

 snow-white, but otherwise unchanged. The rock is a hard 

 white saccharoidal sandstone, regularly porphyritic with small 

 clear feldspars in stout rectangular cross sections for the most 

 part striated, and plainly of secondary growth since they en- 

 close sand grains. It is here eveiwwhere massive. Outcrops 

 are seen in all brook beds in the north part of the town, and 

 it approaches nearest to the older series, in a lane running east 

 from the Moody homestead and along the Winchester road. 

 It is here greatly brecciated and full of quartz and hematite 

 veins. On the east of the boundary line several bands of the 

 older series abut obliquely against this line, so that the quartz- 

 ite on the west rests in manifest discordance, either due to 

 unconformability or faulting against the older series. 



The. Mica Schist east of the Connecticut River in Worth- 

 field. — East of the river only a single limited outcrop of mica 

 schist occurs, a half mile below the village, just opposite Grass 



