DETAILS OP SECTIONS. 23 



the south bank of Whetstone brook, and runs southwesterly to the top of the elevated 

 sandy plain that passes into the Basin No. 4, just considered. (See the line of the 

 section on Plate V.) The terraces appear to be the joint result of Whetstone brook 

 and of Connecticut river. They are, therefore, more numerous than is usual on 

 the Connecticut, and less so than on this same Whetstone brook, a mile from its 

 mouth, as the next section will show. 



The Connecticut valley was probably occupied originally by terrace materials as 

 high as the uppermost of the above terraces on this section, and when the waters 

 gradually subsided, both the Connecticut and Whetstone brook formed channels 

 through these materials, and produced the successive terraces. Why terraces, 

 rather than a continuous slope, were formed, I shall endeavor to show in another 

 place. 



28. This is a quite instructive section, commencing on the south bank of West 

 river at its point of junction with the Connecticut, then extending southwesterly 

 across the village of Brattleborough to the high bank of Whetstone brook, a little 

 west of the village, opposite Burge's factories ; thence across the brook, and up the 

 opposite bank, so as to cross the ' successive terraces, ten in number. The upper 

 one was not measured, on account of the rain. Nor did I ascertain the height of 

 the brook, where the section crosses it, above Connecticut river. 



It will be seen that No. 5, on the left hand part of this section, consists in part 

 of an insulated hillock, crossed a little north of the village; and in the main part 

 of a broad terrace, on which stands the upper and northwest portion of the village. 

 This terrace, as I found by levelling, slopes towards Connecticut river at the rate 

 of 20 feet in 50 rods. Possibly this might have been in part the result of rains 

 for a long period, bringing down from the hill by which the terrace is bounded, 

 deposits of sand. More probably the terrace was formed by the conjoint action of 

 West river and Whetstone brook as a delta terrace, and that its slope was produced 

 by the rapidity of the currents. 



All these terraces are underlaid by argillaceous slate, which shows itself all along 

 the banks of the streams. It is doubtless this solid rock that has determined the 

 present channels of the tributaries to the Connecticut, and caused them to enter 

 that river nearly at right angles. The mere sand and loam of the terraces would 

 soon be washed away in time of freshets,, were it not for this rocky foundation. 



In this section we see a good exemplification of the statement made on a pre- 

 ceding page, that the smaller the stream the smaller are the terraces, and often 

 more numerous too. Here we have ten on Whetstone brook, and nine on West 

 river, yet they do not rise so high as the fourth, on the Connecticut, in Vernon. 



Had I explored the hills by which the valley at Brattleborough is bounded on 

 the west, I might have found beaches, or imperfect terraces, at a much higher level. 

 But when I examined that region my attention had not been called, as it was 

 subsequently, to the subject of beaches. The same remark will apply to nearly 

 all the terraces of which I have given sections on the Connecticut. 



I regret that I did not measure a section across Whetstone brook through the 

 middle of the village of Brattleborough, along the track marked by the figures 1, 

 2, 2, 3, 4, on Plate V. Here it would seem are fewer terraces than at the mouth 



