The latest Meridional System. 



531 



en in treating" of greenstone, which extends from the greenstone ridg- 

 es west of Turner's falls, to the primary strata bounding the eastern 

 side of the valley. The change in the direction of the dip of the sand- 

 stone as we approach the primary strata, can be explained only by 

 supposing an elevation of those strata after the deposition of the sand- 

 stone. At least, the evidence that such was the cause of this anoma- 

 lous dip, is as strong as the evidence that at the other end of the sec- 

 tion the protrusion of the greenstone has occasioned the increased dip 

 of the sandstone. But it is easy to conceive how a protrusion of gra- 

 nite might have taken place in particular places, (and the section 

 shows that granite is associated with the gneiss at the mouth of Mil- 

 ler's river,) and have powerfully affected the incumbent strata for a 

 small distance, without producing a perceptible effect over regions of 

 great extent. And upon the whole, I am inclined thus to explain the 

 case that has been referred to. 



In the Connecticut Valley no rock intervenes between the new red 

 sandstone and the newest tertiary. The strata of the latter are hori- 

 zontal, and were therefore deposited subsequent to the elevation of the 

 system under consideration. Hence we can only say, that the period 

 when this system was developed, was that which intervened between 

 the deposition of the sandstone and the newest tertiary. Beaumont, 

 however, who speaks of this system, as it appears in New Jersey and 

 Delaware, says, that there, " the chalk formation covers the prolon- 

 gation of the ancient beds, which are elevated in a nearly north and 

 south direction, and which form the borders of Connecticut and the 

 river Hudson." If he means, as I suppose he does, that the chalk 

 formation in those states is not dislocated nor elevated, it will follow 

 that the epoch of elevation of this system occurred between the de- 

 position of the sandstone and the chalk. 



4. The North East and South West System. 



This system embraces in my opinion a considerable part of the mi- 

 ca slate in the valley of Worcester, all the northern part of the gneiss 

 range, which on the east side of that valley trends away to the 

 north east, and the western part of the gray wacke formation with 

 the talco-chloritic and mica slate in Cumberland, Smithfield, &c. 

 The dip and direction of the strata in the gneiss range exhibit, proba- 

 bly, the most distinct type of this system. They are more uniform 

 in this range than in any other perhaps in the State. The direction is 

 nearly northeast and southwest ; though I think rather nearer to north 



