Metamorphic Upper Devonian Rooks. 273 



highly refringent globules with moving bubbles. It carries 

 also carbonaceous matter in globules, magnetite, pyrite, a little 

 hornblende and muscovite, which latter forms the partings 

 between the pebbles. It resembles much more closely the 

 quartzite described above, p. 268, c, than it does the rest of the 

 quartzite above and below it. The quartzite continues very 

 compact, vitreous and unevenly bedded for 20 m. down the 

 hill, and in its upper portion carries garnets. It then becomes 

 thin-laminated, separating into layers about 30 mm thick, which 

 are, in fresh cross section, white to bluish vitreous quartz, and 

 the surface of the plates is coated with muscovite. It is finely 

 jointed, and the surfaces of the broad plates are somewhat 

 warped, giving varying dips. Higher up it is cut by great 

 veins of quartz, and in the last outcrop before reaching the 

 upper schist it is again a compact quartzose conglomerate. 

 The strike of the rock averages IN. 60° E., but varies between 

 N. 25° E. and K 70° E. The clip is generally 30°-35° E. but 

 varies from 25° to 50°. At the large quarry a single surface 

 three meters square gave 25° above and 42° below. 



i. On the conformity of the Ltmestone and the overlying 

 Quartzite. — Since the limestone, the magnetite band and the 

 ferruginous quartzites immediately overlying the latter are 

 visibly conformable, and all contain the same fossils as'several 

 times indicated above, there remained in this direction only 

 one question unanswered, namely, what was the relation of the 

 series exposed in the large quarry at the birches and mentioned 

 in the last paragraph, to the quartz conglomerate with flattened 

 pebbles exposed 15 .meters to the east and thus to the whole 

 mass of the quartzite. The latter seems much more metamor- 

 phosed and it might be urged that a fault intervened between 

 the two. On the other hand the conglomerate is typical of 

 that extending from this point northeast to South Vernon and 

 thence north nearly to Brattleboro, and the exact proof of their 

 conformity would greatly enlarge the value of the limestone 

 for fixing the age of the rocks. For this reason I had pits 

 dug three meters apart from the top of the rusty quartzite to 

 the nearest outcrop of the conglomerate to the east, and found 

 the quartzite apparently continuous and no indication of any 

 fault between the two. 



As this did not wholly settle the question I had a trench 

 dug exposing the ledge the whole distance from the fossilif- 

 erous quartzite to the conglomerate. It exposed a continuous 

 surface of the black shaly quartzite for forty-seven meters and 

 conglomerate for three meters, with strike JSL 50° E., dip 40° E., 

 and each layer dipped conformably beneath the succeeding one 

 and the possibility of any fault was wholly excluded. See sec- 

 tion 1. Fig. 3 and c, fig. 2. 



