GEOLOGY OF THE CONNECTICUT VALLEY DISTRICT. 379 



with a variable dip of 30°-8o'' W, Tliis is followed by hornblende again, 

 the slate having been quite limited in amount. Near the forks of a road 

 leading to East Haverhill there is a broader band of whetstone, three 

 hundred feet wide, and a larger (the principal) quarry. This extends 

 north-easterly to join other gneisses of the same material in East Haver- 

 hill, Hornblende succeeds again. Without specifying the changes in 

 order, it is sufificient to say that there are five bands of hornblende schist 

 and five of whetstone slate between the quartzite of Iron Ore mountain 

 and the stream flowing northerly into Oliverian brook on the north-east 

 part of the town line between Piermont and Haverhill. The map shows 

 only one of these hornblendic outcrops. The last half mile of Piermont 

 shows a good soil, with the ledges mostly concealed. This suggests the 

 presence of the limestone of the Calciferous. The hornblende, close to a 

 school-house near the town line, dips 65° N. 70° W. 



I am inclined to carry out the suggestion of a previous page, to the 

 effect that much of this hornblende should be regarded as Huronian. In 

 agreement with this notion, it would form hummocks underlying the 

 mica schists, probably unconformably. Such is the present relation of 

 the first staurolite and hornblende schists mentioned upon this section. 

 Lateral force exerted in subsequent periods seems to have exaggerated 

 the discordance. This theory will explain the occurrence of the whet- 

 stone rock, in limited outlying patches, sometimes exhausted by quarry- 

 ing. Were it interstratified with the hornblende, it should descend into 

 the earth at the same angle to indefinite depths. This theory, then, re- 

 gards the eastern part of the hornblende of Piermont the same with that 

 in Hanover, Eyme, and Orford, bordering the west line of the Bethlehem 

 group. A similar view will make plain the proper relations of the horn- 

 blende rock in Fig. 59; but the more western of these hornblende ranges 

 must remain with the Coos group, as they are evidently interstratified 

 with each other. 



On ascending the west side of the valley, on the town line just named, 

 the ledges bear more resemblance to the calciferous layers found in Ver- 

 mont. They dip 70° S. 75° W. There is a little hornblende with it at 

 first, then it is soft, and, by J. Wallace's, hard, from the abundance of 

 silica. On Catamount hill, just in the edge of Piermont, is an interest- 

 ing mass of eruptive granite, unlike any other granite seen in the state. 



