SOME RIVERS OF CONNECTICUT. 373 



This lowland is interrupted by a series of trap ridges, which in 

 general present steep faces toward the west, whereas their east- 

 ward slope is gradual, less than the dip of the sandstones. 



Tlie iiplaiid plateau. Suppose we ascend the highest point 

 of these trap ridges, the old tower on Talcott Mt., nine miles 

 west of Hartford ; we are 900 feet above the sea level and more 

 than 600 above the plain at our feet. A few miles to the west 

 across the sandstone valley, rise the cr3'stalline uplands, which 

 extend far to the north and to the south. On the east across the 

 Connecticut we see the eastern uplands. The first impression, 

 which comes to one as he gazes upon these uplands and which 

 is strengthened with each view, is that few hills rise above the 

 general level of the plateau ; the crest line is nearly horizontal, 

 declining gently to Long Island Sound. Above this general 

 level are a few rounded domes, but no sharp, towering peaks. 

 Below it valleys have been cut, but they do not destroy the 

 plateau - like appearance. A view from the western plateau 

 across the sandstone valley shows the remarkably even crest 

 line of the trap ridges, a crest line which approximates in height 

 the uplands on the east and west. A nearer view of the upland 

 corroborates our first impressions of the gently rolling character 

 of the inter -stream surfaces, but we have a better view of the 

 valleys which have been sunk beneath the general level and of the 

 low rounded hills which rise above it. In popular parlance the 

 country is "hilly." It is uneven, not because there are high hills, 

 but rather because there are deep valleys. If in imagination we 

 fill up these valleys and the wide Triassic lowland to the general 

 level of the broad inter -stream surfaces, we shall have con- 

 structed a gently undulating plateau, dipping to the south and 

 east — a peneplain.^ 



Origin of the peneplain. This is not a constructional surface, 

 for the rocks are greatly tilted, folded and faulted, so that the 

 surface consequent upon such disturbance must have been com- 

 plex and mountainous. Long subaerial denudation upon a 

 folded and faulted mass when the land stood much lower than 



' Am. Jour, of Sci., 3d ser., vol. xxxvii, p. 430. 



