DAVIS : RIVER TERRACES IN NEW ENGLAND. 343 



of streams wherever they are free to swing in loose drift of fine texture ; 

 and it appears from Emerson's description that such was the case with 

 the Connecticut while it was sweeping away the fine silts of the Mon- 

 tague " lakes." 



Second, the leisurely lateral swinging of Saxtons and Westfield 

 rivers at high levels, as recorded by the upper members of the terrace 

 flights in the valleys of those tributaries of the Connecticut, show that 

 they were not hurried in the early stages of their work of degradation ; 

 yet hurried they must have been had the master river suddenly in- 

 trenched itself in the weak drift filling of its aggraded valley. There 

 are, to be sure, certain rock aud till barriers between these terrace 

 flights and the junction of their streams with the Connecticut, and such 

 barriers might separate a quickly degrading trunk river from slowly de- 

 grading tributaries ; but it is believed that the barriers are too low to 

 have been encountered until after the highdevel terraces had been 

 carved. 



Third, there are certain points where the Connecticut itself exhibits 

 stepping terraces at altitudes of at least eighty or more feet above its 

 present level. The best of these are at East Deerfield, two miles south 

 of Turner's Falls, where the Fitchburg railroad crosses a group of ter- 

 races between the mouth of the Deerfield and the east-south bend of 

 the Connecticut. Here an eastern profile from the high terrace south 

 of the railroad station to the river crosses five terraces, the height of 

 whose scarps I have estimated at 30, 25, 15, 18, and 35 feet (total, 123 

 feet). If the profile be taken northward from the high terrace, seven 

 scarps are passed, including the descent from the lowest plain to the 

 river, with heights estimated at 30, 25, 10, 5, 15, 10, and 15 feet 

 (total, 110 feet). The locality of these terraces is openly connected 

 with that of the high scarps in the Montague silts ; and hence a lei- 

 surely process of degradation with repeated lateral swinging is probable 

 there as well as here. The only essential difference between the two 

 localities is that the terraces are for good reason preserved in East Deer- 

 field, where the river has become increasingly constrained by successive 

 discoveries of sandstone ledges, while they have been destroyed further 

 south where the river has been free to swing at modern levels. 



The Connecticut near Springfield, Mass. There are few ledges 

 exposed hereabouts, and few stepping terraces. The high terrace that 

 is nearly continuous on the east side of the valley from Springfield up 

 to Chicopee, is now swept by the river for a part of its length, and 

 within this stretch a sandstone ledge is seen in the river bank. In 

 vol. xxxviii. — no. 7 5 



