Metamorphic Upper Devonian Mochs. 373 



Hill, and 200 rods from the nearest outcrop of hornblende 

 rock, on the west side of the river. It agrees in texture with 

 the lowest beds of schist on the west of the Connecticut, is 

 fine grained, and carries few accessions. It abounds in flat- 

 tened cavities, which seem to be the obscure traces of fossil 

 shells, but they are wholly indeterminable, if indeed they be 

 of organic origin at all. Upon the joint faces are abundant 

 weathered crystals of a flesh colored zeolite, apparently chaba- 

 zite. The exact locality is by the brook crossing, at a mill 

 pond near A. Billings'. 



Conclusion. 



The section below seems to me to represent the succession of 

 the beds represented, the newest above. 



1. 



Mica schist, 



9. 



Hornblende schist and 



2. 



Hornblende schist, 





Magnetite, 



3. 



Mica schist, 



10. 



Limestone. 



4. 



Hornblende schist, 



11. 



Hornblende schist, 



5. 



Mica schist, 



12. 



Quartzite conglomerate, 



6. 



Hornblende schist, 



13. 



Argillite, 



/ . 



Mica schist, 



14. 



Calciferous mica schist. 



8. 



Quartzite, 







Originally heavy beds of shale (a) graduated upward into a 

 great series of feldspathic sandstones (b) and conglomerates, 

 which contained a band of crinoidal limestone with a local de- 

 velopment of iron ore near its surface. Above this was an ex- 

 tensive series of shales (c) with several intercalated beds of 

 impure limestone. The first series has changed into a crumpled 

 and cleaved phyllite to which the name argillite has been 

 for a long time appropriated. The second series has passed 

 through all the changes to a gneiss so complete that Professor 

 Hitchcock insists on associating it with the Bethlehem gneiss — 

 quartzite with flattened pebbles, muscovite quartzite, biotite 

 quartzite, feldspathic quartzite often porphyritic, and complete 

 biotite gneiss often becoming chloritic from superficial change. 



The limestone has become most coarsely crystalline and the 

 lime and iron have been carried far out into the quartzites 

 above and below to form hornblende schists and complex horn- 

 blende-chlorite pyrite rocks. 



The iron ore forms a bed of magnetite or a magnetite rock. 



The upper series is changed to complete mica-schists span- 

 gled with transverse biotite crystals, often loaded with garnets 

 and staurolites ; while the limestone beds are changed from the 

 surface toward the center into hornblende schist beds abstract- 

 ing the iron from an adjacent band of the shales. 



