274 



BASALTIC ROCKS. 



commences at West Rock, near New-Haven, and 

 extends from thence almost in a direct line to 

 Mount Tom, near Northampton, in Massachusetts. 

 From hence it stretches north through the Connec- 

 ticut Valley, in connexion with the red sandstone, 

 and so on into Vermont and New-Hampshire, asso- 

 ciated with argillaceous and mica slate. We also 

 meet with ridges and beds of greenstone in other 

 parts of Connecticut, and particularly east of the 

 main ridge already described. The greenstone in 

 the eastern part of Massachusetts is of a dark green 

 colour, from the presence of epidote, while that in 

 the Connecticut Valley exhibits a gray or iron-rust 

 colour, from the presence of oxide of iron. It 

 seems to be a fine-grained mixture of hornblende 

 and feldspar ; sometimes columnar, frequently amyg- 

 daloidal* and amorphous The scenery of the Con- 

 necticut Valley derives its boldness, wildness, and 

 beauty principally from the greenstone ridges that 

 have been described. The Palisades, or Cloister 

 Mountain, on the Hudson, near New-York, are ba- 

 saltic greenstone : and, as we go west, we strike it 

 again at Patterson, where it forms the Falls of the 

 Passaic, and the First and Second Mountains ; and, 

 a little farther west, Freakness Ridge. A few miles 

 south, and midway between the Hudson and the 

 Delaware, we find it forming a considerable eleva- 

 tion near Somerville, called the Somerville Trap 

 Ridge. A section of the state still farther south> 

 striking through Trenton, presents several ridges 

 of greenstone or trap formation, as at Goat Hill, 

 Belle Mount, Smith's Hill, &c. ; there being, in fact, 

 a double or triple chain of trap hills extending north 

 and south near the centre of the state, conimen* 



* From " ami/gcZaZa," an almond. Any rock containing glob- 

 ular masses scattered through it, like almonds in a cake, is said 

 to be amygdaloidal. 



t From '* a," without, and " morphe/^ form : destitute of reg- 

 ular form. 



