134 



nearly east- west strike, it seems reasonable to infer that this 

 granitic belt extends eastward beneath the southern part of 

 Cape Cod Bay, and that it is the source of the granitic boulders 

 mentioned by Prof. Hitchcock as strewn over the Cape to the 

 southward. 



The granite cutting the Carboniferous and more ancient 

 slates near NeAvport, R.I., is also regarded as Montalban, 

 and as probably connected with the belt just described. It 

 is mostly fine-grained, usually contains some hornblende, and 

 appears to resemble the quaternary granites of the Connecticut 

 Valley. These latter occur in several large masses along the 

 borders of the Triassic sandstone, and, though beyond the proper 

 geographic range of this paper, merit some attention here as 

 being the only granite of Montalban or any other age occurring 

 in large masses in Massachusetts, west of the Nashua Yalley. 

 The large granitic area in Williamsburg, Goshen, Westhamp- 

 ton, and Northampton, and also that east of the Connecticut, 

 in Amherst, include, according to the observations of Prof. 

 Hitchcock,^ considerable mica slate, which is associated with 

 the granite in such a manner as to prove the exotic nature of 

 much of the latter. A glance at a geological map of the State 

 will show that the granite of Williamsburg and Westhampton 

 lies on the line of strike of the gneiss at Shelburne Falls, and 

 that this granitic area is elongated in a north and south direc- 

 tion. It represents, as I conceive, the extension southward of 

 the' Shelburne anticlinal previously mentioned (p. 127). And 

 the great disturbance observable in the gneiss in the Deerfield 

 River at Shelburne Falls has only been carried a step further 

 to produce the extravasated granite of Williamsburg. The 

 rocks composing the two areas, one in Northampton and Hat- 

 field, and the other in Ludlow and Belchertown, marked as 

 ' ' syenite " (hornblendic granite) on the geological map of 

 Prof. Hitchcock, are here included among the Montalban gran- 

 ites. My reasons for this are : (1) These syenites, so-called, 



I Final Report on the Geol. of Mass., p. 682. 



