48 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



a subsequent drainage through differential erosion, were made 

 so long ago that evidence of them has been largely destroyed. 



The foregoing conclusion practically eliminates hypothesis IV 

 that the Still developed from the beginning as a subsequent 

 stream in the direction in which it now flows. This hypothesis 

 holds good only for the short portion of the lower course of the 

 present river, that is, the part representing the short tributary 

 of the Housatonic which captured and reversed the original 

 Still. 



DEPARTURES OF STILL RIVER FROM ITS PREGLACIAL 



CHANNEL 



Between Danbury and Beaver Brook Mountain the Still de- 

 parts widely from its former channel, as shown in fig. 6. At the 

 foot of Liberty Street in Danbury the river makes a sharp turn 

 to the southeast, flows through a flat plain, and for some distance 

 follows the limestone valley of the Umpog, meeting the latter 

 stream in a swampy meadow. It then cuts across the western 

 end of Shelter Rock in a gorge-like valley not over 200 feet wide. 

 Outcrops of a gneissoid schist on the valley sides and rapids in 

 the stream bear witness to the youthfulness of this portion of the 

 river channel. 



An open valley which extends from the foot of Liberty 

 Street in a northeasterly direction (the railroad follows it) marks 

 the former course of Still River, but after the stream was 

 forced out of this course and superimposed across the end of 

 Shelter Rock by the accumulation of drift in the central and 

 northern parts of the valley, it was unable to regain its old channel 

 until near Beaver Brook Mountain. The deposits of 'drift not 

 only have kept the Still confined to the eastern side of its valley 

 but have forced a tributary from the west to flow along the edge 

 of the valley for a mile before it joins its master stream. 



About a mile north of Brookfield Junction, Still River valley 

 begins to narrow, and at Brookfield the river, here crowded to the 

 extreme eastern side, is cutting a gorge through limestone. The 

 preglacial course of the Still in the Brookfield region seems to 

 have been near the center of the valley where it was joined by 

 Long Brook and other short, direct streams draining the hillsides. 

 The glacier, however, left a thick blanket of drift in the middle 



