222 GEOLOGY OF OLD HAMPSHIEE COUNTY, MASS. 



THE AMHERST FELDSPATHIC MICA-SCHIST (CONWAY SCHIST). 

 LEVERETT. 



West of the band of whetstone-schist in South Leverett begins the 

 broad area covered by the Amherst feldspathic mica-schist and granite in 

 inextricable confusion. It is in this northern portion so purely granite, and 

 the shreds of schist are so impregnated with granitic material, that I have 

 marked but a small portion as schist upon the map. 



The Conway mica-schist of the western side of the Connecticut Valley, 

 where it approaches the great masses of granite from Williamsburg to 

 Montgomery, can be seen along both dip and strike to become more 

 coarsely crystalline and feldspathic, while the plumbaginous material dis- 

 appears or crystallizes into graphite and thus colors the rock less. The 

 garnet and staurolite also disappear in large measure, and a rock results 

 closely comparable to that which underlies the towns of Amherst and 

 Hadley 



Furthermore, the same mica-schist in Horse Mountain, on the western 

 line of Hatfield, dips west and formerly mantled over the hornblende- 

 granite at its eastern foot. It is here not greatly different from much of 

 the Amherst rock, and I assume that it reappears in the nearest outcrops 

 on the east of the river in Mount Warner, where it forms a much-disturbed 

 syncliiie, and then extends across Amherst, on its eastern border dipi)ing 

 west — that is, away from the hornblendic band which underlies it, and which 

 I have already traced across Pelham. 



Starting thus from the exact lithological identity of the Conway mica- 

 schist of Northfield on the east and that of Coleraine directly opposite, west 

 of the Connecticut, I liave shown that the coarse mica-schists of the north- 

 west of Leverett occupy the same stratigraphical position as the Conway 

 schist in Northfield, and then have traced the Leverett schists southwai'd 

 into continuity with the Amherst schist. The latter is then shown to be 

 identical with the altered representative of the Conway schist on the west 

 of the river just opposite, and the same parallelism can be proved clear 

 across the State. 



