THE RIVER SYSTEM OF CONNECTICUT 



475 



to the absence over the greater part of the surrounding area of 

 widely different rocks in thin beds, the difficulties of locating 

 fault planes are almost infinitely increased ; and, indeed, except 

 under especially fortuitous conditions they elude observation. 

 Having established, however, a relationship in one area, the 

 problem is before us to determine 

 whether the river system of the larger 

 area of Connecticut exhibits any indi- 

 cation of the existence of rectilinear 

 directions more or less persistent em- 

 braced in a network of parallel series 

 like that of the Pomperaug Valley; or, 

 if this be not true, whether any other 

 persistent and recurrent directions can 

 be observed. It will be further of 

 special interest if such a system affords 

 indication of a regular space-interval 

 between such parallel lines of drainage. 

 The oriejited drainage of the Shepaiig 

 River. — In prosecuting our inquiry 

 regarding the orientation of the drain- 

 age lines of Connecticut, the valley of 

 the Shepaug River (its southern por- 

 tion) was first examined, since this 

 basin immediately adjoins to the west 

 that of the Pomperaug. The diagram , , 



of this river traced from the atlas ^ ^^. , 



Fig. 2. — Diagram to show 



sheet of the map of Connecticut, pre- the relationship of drainage lines 



pared by the topographic corps of the in the basin of the Shepaug 



United States Geological Survey ^^^^''^^ ^^^ P''^^^^^^^^^^^' ^"^ 



-' joint lines of the neighboring 

 (Fig. 2), affords clear evidence that Po^peraug basin. 



the geological structure planes have 



here played an important part in giving direction to the river's 



channels. The dotted lines of the figure show the inferred 



approximate positions of fault planes whose course the river 



has adopted. The most marked adhesion of the river or its 



