THE TERRACES OF THE CONNECTICUT. 737 



AN OLD OXBOW OF FOUT KIVEK. 



From the south end of Hadley street one may follow the Champlain 

 clays continuously for a long- distance south in the river bank. Near where 

 they sink below the water a terrace scarp belonging to Fort River is cut 

 off in the bank of the Connecticut. The last house passed in going sovith 

 from Hadley and before crossing the bridge over Fort River stands on the 

 edge of the completed flood plain of the Connecticut and looks down over 

 this scarp to a lower plain, formerly part of the flood plain of Fort River, 

 which here runs parallel to and just east of the Connecticut. In fig. 48, a 

 represents the southern termination of the Champlain clays, which a few 

 feet north furnished the leaves described on page 718, and still farther north 

 abound in claystones; t, the bottom sands of the Connecticut when it 

 flowed at a level higlier than at present by an amount somewhat greater 



Fig. 48. — An old oxbow of Fort Kiver cut by the Connecticut below Hadley. d, d\ old lied of Fort Eiver. 



than its own depth. These are coarse to medium grained straticulate 

 sands, which rest unconformably upon the clay and extend with a thickness 

 of 20 feet to the point Avhere the old Fort River terrace scarp is cut off" in 

 the present river bank. Here these sands end, their horizontal beds abut- 

 ting unconformably against c and e, except that at lowest water their lower 

 beds can be traced beneath c for the whole length of the exposure. 



The scarp, partly exposed and partly submerged, against which these 

 sands end, registers the farthest northward swing of Fort River in throwing 

 out an oxbow here on its west side; c, which is a fine, horizontally bedded 

 and straticulate sand, is the bottom sand of Fort River as it swung across 

 its flood plain; d and d' are two cross-sections of the old oxbow of the trib- 

 utary, now cut into by the main stream. At d the stream plainly flowed 

 toward the west — that is, toward the reader; at d', toward the east; and the 

 Connecticut has cut across this old oxbow, as indicated by the dotted lines. 



These old river Ijeds are the exact equivalents of the present bed of 

 Fort River — a stratified deposit of leaves, twigs, logs, and seeds in fine 



MON XXIX il 



