36 i B. K. Emerson — " JBernardston Series" of 



Just after crossing the State line into South Yernon it bends 

 sharply to the southwest, recrosses the State line and, at the 

 point where the gristmill road (J. M. Pickett) crosses the 

 town-line, bends again northwest and swings in a great curve 

 north across Yernon. All this is well exposed just north of 

 the last house before crossing the line (M. Merrills), and the 

 argillite where it is nipped by the sharply bending quartzite is 

 greatly crushed and filled with quartz combs. This boundary 

 crosses the next road north — the old Bernardston- Yernon road 

 — at a small abandoned house (two houses below the school 

 house) where the brook comes nearest the road. Just behind 

 this house in the side of the brook is exposed a most interesting 

 junction of the conglomerate upon the argillite. Commencing 

 at a ruined dam perhaps 15 rods from the house we find tj^pical 

 argillite which changes through a few feet of spangled schist 

 into thin fissile black muscovitic quartzite with some thicker 

 highly crystalline layers, and this graduates into a highly 

 muscovitic very vitreous quartzite, which is at one place a 

 conglomerate of rounded quartz pebbles 2 to 4 in. long. This 

 is where the water falls over a reef 3 to 4 feet high ; it is 

 2 rods below a wooden bridge. Immediately below is a bed 

 of heavy hornblende rock, massive, in places showing a reticu- 

 lated structure : masses of this rock built into the piers of a 

 wrecked bridge just behind the house show pebbles, and con- 

 tain also much green mica, often quite coarse and resembling 

 the more gneissoid rock found out over the South Yernon 

 plain to the river and classed by Professor Hitchcock as Beth- 

 lehem gneiss. The series strikes 1ST. 55° W. and dips 45° E. 

 The outcrop is continuous and shows a gradual passage through 

 a spangled argillite and line-grained quartzite into conglom- 

 erate, often coarsely garnetiferous, the change being effected 

 within 50 feet and showing no trace of unconformity. Many 

 masses of a thin fissile pyritous magnetite occur here, but the 

 bed could not be found in place. 



East of the boundary line just described, across Yernon to 

 the river, the whole area is underlaid by the basal quartzite 

 except where the West Northfielcl schist series extends across 

 the State line, west of the village of South Yernon ; and across 

 the brook it rises in the hill back of S. Titus's, where the road 

 to the lily pond branches from the Brattleboro road. It dips 

 for the most part to the east except east of the lily pond, 

 where a minor fold of considerable size occurs, caused by the 

 sharp bend of the quartzite on the State line, and here the beds 

 dip south. Followed eastward it becomes more and more 

 feldspathic and the muscovite is largely replaced by biotite, 

 forming a completely gneissoid rock. It is here not distinguish- 



