PHENOMENA AFFECTING RIVEfR THEORY 229 



Other examples of terracing are found : at Port Kent, on the delta of 

 the Ausable ; in the Hudson Valley, at Catskill, Kingston, Newburg, and 

 Haverstraw. The fact that the benchings are not conspicuous or visible 

 in groups from single viewpoints has no bearing on the question of their 

 genesis. 



Origin. — Enough has been said to make the fact clear that the terraces 

 of the Connecticut Valley, like those in the Winooski, Champlain, and 

 Hudson, are not the product of simple river work, but were made by the 

 combined action of subsiding static waters, inflowing tributaries and out- 

 flowing currents. The important fact to recognize is that the terraces 

 were formed in static waters. Whether these waters were lake or sea is 

 another matter. 



At the higher levels the wave-work of the static water and the tributary 

 stream inflow were the more effective factors. With the falling of the 

 water level and consequent restriction of the area the outflowing currents 

 increased in effectiveness, until finally the river was left as the sole agent, 

 producing the plains at, and possibly just above, the present river level. 



DETRITUS. 



Character. — The fine composition or clayey character of most of the 

 material composing the terraces and the difficulty of explaining it under 

 the river theory was recognized by Dana. Illustrating this we quote : 



"From tlae above, the mean velocity for the whole river from Haverhill to 

 Middletown would have been, assuming that the relations of the land to the 

 sealevel were the same as now, over 12 miles an hour, even supposing the 

 mean width to have been but 2,500 feet. 



"This great velocity, or even one of 10 miles an hour, is not compatible with 

 the character of the deposits which lie at different levels beneath the surface 

 of the stream, both those at 140 feet below the surface and those at higher 

 levels" (American Journal of Science, vol. 23, page 192). 



"It is to be remembered that the sand beds and those of finer material ordi- 

 narily make not only the lower terraces, but also the highest, where tribu- 

 taries are absent to within 50 or often 20 or 30 feet of their tops, and that this 

 is so even high up the Connecticut, as at Barnet, not two miles south of the 

 junction with the Passumpsic, where these finer deposits extended to a level 

 of 150 to 200 feet above low water in the river" (page 194). 



To reduce the velocity of the supposed river, appeal was first made to 

 dams; but such were ruled out, except a possible ice-jam below Middle- 

 town. Dana says : 



"For making the clay-beds north of Amherst the Middletown dam would 

 have been of no avail, and besides this dam there is no satisfactory evidence 

 of any other" (page 195). 



