482 WILLIAM HERBERT HOBBS 



Farmington and Ouinnipiac at Plainville, and h^, which follows 

 the easterly course of the Connecticut for a distance below Mid- 

 dletown. 



A trough line seems to be indicated in the Salmon River and 

 a branch of the Willimantic {^g). This direction is N. 48° E. 

 and does not correspond to an)^ observed fault direction in the 

 Pomperaug Valley area. Neither is it the diagonal of any very 

 simple composite block of that area, which otherwise might indi- 

 cate its relationship to this system. 



Conclusions. — In conclusion it may be stated that the rivers 

 of Connecticut seem to indicate by the orientation of their chan- 

 nels the existence of a regular network composed of a number 

 of intersecting series of parallel lines, which for lack of a better 

 term have been designated trough lines ; and, further, that with two 

 exceptions the more important of these trough lines correspond 

 closely in direction with the directions of fault series observed 

 to characterize the complexly faulted area of Newark rocks in 

 the Pomperaug Valley. Of the two exceptions to the rule, the 

 more noteworthy one (N. ± 5° E.) fills an important gap in 

 the system of faults determined for that area. This study is 

 therefore in its bearing a confirmation of the conclusions arrived 

 at by Kjerulf, Daubree, and Brogger, who have seen in the 

 orientation of water courses the strong directing influence of 

 geological structure planes. 



There are obviously a number of ways in which the dislocations 

 of a region, like the one under consideration, might be made to 

 account for the orientation of stream courses. The direction of 

 streams by the joint or fault planes themselves may be competent 

 to explain the network indicated, more particularly if the streams 

 began their cutting in the soft Newark sediments, which easily 

 sustain secondary fractures near fault planes. That some voids 

 occur along the fault planes of the Pomperaug Valley would seem 

 to be indicated by the fact that these planes have conducted the 

 underground waters to the surface at so many places within the 

 area of the Newark rocks. Tension joints should, however, be 

 more effective than compression joints in the control of drainage 



