No. 3O.] GLACIAL DEPOSITS. 57 



the way from the Umpog-Saugatuck divide to Bethel. North 

 of Bethel, the drainage seems to have been gathered chiefly in 

 streams flowing on each side of the low ridge occupying the 

 center of the valley ; consequently the gravel was deposited along 

 the sides and southern end of the ridge and in the sag which 

 cuts across its northern end. The row of kames at the north end 

 of Umpog Swamp, several knolls of drift in Bethel, and the 

 kame-like deposits and esker north of Grassy Plain were laid 

 down successively as the ice retreated down the valley. During 

 this period, the drainage was ponded between the ice front and 

 the Umpog-Saugatuck divide. 



Uncovering the Still-Croton valley did not give the glacial 

 drainage any lower outlet than the Umpog-Saugatuck divide 

 afforded (fig. 8, B and C.) 



The heavy deposits of boulder clay forming the moraine 

 which blocks the Rocky River valley indicate the next halting 

 place of the glacier. In this period the ice margin formed an 

 irregular northeast-southwest line about a mile north of Danbury. 

 The country west and south of Danbury was thus uncovered, but 

 the lower part of Still River valley was either covered by the ice 

 sheet or occupied by an ice lobe. The drainage was, therefore, up 

 the river valley, and being concentrated along the valley sides 

 resulted in the accumulation of sand and gravel at the foot of 

 rocky slopes. It is possible that an ice lobe extended down the 

 old Rocky River valley, perhaps occupying much of the country 

 between Beaver Brook Mountain and the high ridge west of the 

 valley. The streams issuing from this part of the ice front would 

 have laid down the eskers and kame gravels north of Danbury 

 and the thick mantle of drift over which Still River flows through 

 the city. As would be expected, this accumulation of material 

 ponded all the north-flowing streams Umpog Creek, Beaver 

 Brook, and smaller nameless ones and at the same time 

 pushed Still River, at its mouth, to the southern side of its 

 valley. Beaver Brook valley, Umpog valley, and all the Dan- 

 bury basin must have been flooded during this period up to the 

 height of the " railroad divide." Within the area covered by the 

 city, the valley was filled up to at least 70 feet and probably much 

 more than that above its former level. Flowing at this higher 

 level, the river was thrown out of its course and here and there 



