4 80 WILLI A M HERBER T HOBBS 



explain the lower course of the Housatonic, which similarly 

 deserts the limestone to cross the uplands. The presence of 

 important structure planes in these positions would, in the view 

 of the writer, afford the simpler explanation. It will be noted 

 here that there is considerable uniformity in the spacing of the 

 trough lines of this series, especially a^, a^, a^. 



The next most strikinor series of trou^'h lines is indicated 

 in the course of the Connecticut from Springfield to Hartford 

 (<;j ), a distance of twenty-six miles; of the Willimantic (<^3); 

 of the Mt. Hope (<?2«)! the Little {c^); and a long stretch of 

 the Quinebaug {c^). The direction of these trough lines is 

 about N. 5° E., though this is not one of those observed to 

 characterize the faults in the Pomperaug Valley area. Again, 

 the spacing of these trough lines is quite regular if we regard 

 the space between the Connecticut and the Willimantic as a 

 double interval. More striking, perhaps, than any of these 

 trough lines is the one indicated in the series of smaller streams 

 which extend along the line Cr^ of the map. These streams are 

 too small to deserve names upon a map of this scale, but some 

 of them are known as Five-Mile River, Whetstone Brook, Moosup 

 River, Mt. Misery Brook, etc. The direction of the series was in 

 fact obtained from them and applied to the other trough lines in 

 the series. This direction, while not an observed fault direction, 

 corresponds to the longer diagonal of two unit orographic blocks 

 of the Pomperaug Valley placed in contact along their shorter 

 sides (see the dotted diagonal in Fig. i), and thus it fills an 

 important gap in the system of dislocations outlined. 



The trough lines d^, d.^, and d^, which trend N. ±: 15° E., rep- 

 resent a third series. The line (^^, which corresponds in position 

 with no very important stream, is an observed fault of the 

 Pomperaug Valley area (extended), in which area, however, the 

 Pomperaug River adheres closely to its direction ; d^ corre- 

 sponds closely for a distance of about fifteen miles with the 

 course of the lower Naugatuck ; while to the south the lower 

 Housatonic flows in a nearly parallel direction some distance 

 farther to the east. Most striking of this series is the trough 



