BASINS. 105 



18. The country between the Cat Bow in Connecticut River and the north town line of Guildhall, pre- 

 sents a remarkably fine basin for the space of seven miles, when it is intercepted by a ridge of granite. 



19. The Connecticut valley presents a very beautiful series of terraces for the next eighteen miles, along 

 the route of the Grand Trunk Railroad, and beyond to the north line of Bloomfield, which is embraced in 

 the nineteenth basin. 



20. The twentieth basin extends from Bloomfield, north line, to the vicinity of Colebrook, N. H., over a 

 distance of five and a half miles, when the high Mt. Monadnock of Vermont interposes a barrier, though 

 now sufficiently worn away to permit the passage of the river. 



21. The valley north of Colebrook, in the Vermont towns of Lemmington and Canaan, becomes smaller : 

 the country is very romantic with its high mountains. Some of the terraces upon this basin are quite high. 

 The basin is six miles long. 



22. This brings ITS nearly to the village of Canaan, where there is a fine exhibition of terraces. We did 

 not visit the valley of the Connecticut beyond the limits of Vermont, and therefore do not feel authorized 

 to suppose the presence of more than one basin for the sixteen miles intervening between the northern 

 limit of No. 21 and Connecticut Lake. 



The whole length of the river is about 300 miles, and its source is 1589 feet above the ocean. We will 

 now proceed to enumerate some of the particular facts worthy of note in each of these basins. In order to 

 give symmetry to this treatise upon the Surface Geology of Connecticut River, we consider it necessary to 

 state briefly the most important facts relating to the terraces found along its banks in Massachusetts and 

 Connecticut. 



BASINS ON CONNECTICUT EIVER IN CONNECTICUT AND MASSACHUSETTS. 



The Connecticut River has a very small delta at its mouth above tide water. The maps show but a lit- 

 tle jutting out of the land into Long Island Sound. The river is constantly bringing down material into 

 the Sound, whose amount cannot be estimated accurately. Should the land rise in future a few hundred 

 feet, it would probably show quite a large accumulation of detritus. The smallness of this delta is owing 

 partly to the fact that the present mouth of the river has not always been the point of union between the 

 river and the ocean. Two quite extensive beds formerly carried the waters to New Haven, Ct. ; the one 

 commencing at Mt. Holyoke, in the third basin, and continuing to New Haven, west of the Greenstone 

 range, and in the route of the Canal Railroad from New Haven to Northampton, Mass. Nowhere is this 

 valley more than one hundred and thirty-four feet above the present level of the river at Northampton, and 

 the terraces on the river near Northampton are much higher than this. The other bed is along the route 

 of the Hartford and New Haven Railroad ; no part of which can be more than twenty or thirty feet above 

 the present level of the Connecticut at Hartford. 



The terraces on the first basin resemble beaches, and are probably formed by a combination of fluviatile 

 and oceanic agencies. The course of the river from Middletown to Lyme its mouth is through meta- 

 morphic rocks, like those in Vermont, while the remainder of its course from the south line of Vermont is 

 in a sandstone of secondary age. As the sandstone is easier to disintegrate than the metamorphic rocks, 

 this may have been a reason why the basins in middle Connecticut and Massachusetts are so much larger 

 than the others. Certain it is, that during the age of the sandstone and earlier alluvium, the river preferred 

 the formation of the former to the latter for its course, for the present bed in the twenty five miles below 

 Middletown through the older rocks exhibits a narrow valley, bounded by steep and rocky hills, with 

 occasional small meadows or terraces. The reason why the river has often chosen a later rocky to an 

 earlier sandy region for its course will be explained hereafter. 



The terraces are very finely developed in the second basin from Middletown to Mt. Holyoke. The number 

 of terraces does not usually exceed four, nor do they rise over two hundred feet above the river the highest, 

 a gorge terrace south of Mt. Holyoke, being 298 feet above the ocean. The upper terrace on the east side 

 from Mt. Holyoke to East Hartford has a considerable slope to the south ; its height at various places being 

 as follows : at Mt. Holyoke 298 feet above the ocean ; Williamansett, Mass., 268 feet ; at Springfield, 

 Mass., and Longmeadow Mass., 200 feet ; at East Windsor, Ct., 96 feet : and at East Hartford, Ct., 61 feet. 

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