182 Scientific Geology. 



given them still farther modifications. Nor ought we to leave out of 

 the account any other deluges of a date subsequent to that of the 

 elevation of the strata, that may have swept over the land. 



The valleys through which the Connecticut and its tributaries 

 flow, are the largest and most remarkable in the State. The ordinary 

 laws of physical geography seem here to be set at defiance ; so much 

 so, that a late ingenious writer* doubted whether I had correctly rep- 

 resented the " Geology of the Connecticut," because the course of the 

 rivers, and the direction of the mountain ridges, were described as 

 having so little correspondence with the rock formations. But the 

 features of the geology, as well as of the scenery, along this river, 

 are too obvious to be easily mistaken in their great outlines, which 

 are alone concerned in this enquiry. The relation of the rivers to 

 the different mountain ridges and rock formations, I hope to render 

 intelligible by the aid of the accompanying map, (See Plate XV.) on 

 which are traced only the chief outlines of the surface. To pre- 

 sent all the smaller irregularities of surface, I found would only ob- 

 scure the points which I wish to illustrate. 



That portion of the valley of the Connecticut to which I shall spe- 

 cially refer at this time, extends from near the north line of Massa- 

 chusetts to Long Island Sound at New Haven. It is bounded by 

 broad and generally lofty primary mountains ; which, at the north- 

 ern and southern extremities of the valley, converge until they almost 

 meet, as may be seen on the map. They are farthest asunder about 

 in the latitude of Hartford. This valley is divided diagonally by a 

 ridge of greenstone ; commencing on the south with West Rock at 

 New Haven, and extending, with few interruptions, to East Hamp- 

 ton, where it attains an elevation of about 1000 feet, and forms Mount 

 Tom. Here it crosses the Connecticut, and on the opposite bank, 

 forms Mount Holyoke ; and continuing a few miles farther, termin- 

 ates in Belchertown, as already described in the second part of this 

 Report. This greenstone range is separated by vallies from the pri- 

 mary ranges at its extremities ; and there are several places where it 

 almost entirely disappears, as at the point in Hamden, through which 

 passes the Farmington Canal : unless any are disposed to regard 

 Mount Carmel, in that town, as the southern extremity of the range, 

 and the hills to the southwest, as a distinct range. Several other 



* Darby's View of the United States, p. 164. 



