30 A. P. BRIGHAM — GLACIAL FLOOD DEPOSITS. 



shall be fairly made out, it will be possible to trace with some degree of 

 defmiteness the progress of deposition in the Chenango and the several 

 associated valleys east and west, which must have witnessed much the 

 same order of events. It is believed that differential northward depres- 

 sion has in any case been an important factor in the history of these ac- 

 cumulations. 



All the deposits here passed in review, save perhaps the deeper filling 

 of the valley, must belong to the later phases of glaciation in this region- 

 The kame terraces, which are typical phenomena of recession, recur per- 

 sistently from near Binghamton to Smyrna. The retirement was inter- 

 rupted by important pauses, perhaps with episodes of readvance, about 

 Chenango Forks and Oxford, as is evident from the kames and associated 

 phenomena of those localities. From some sections of the main valley, 

 as above Chenango forks and from North Norwich to Hamilton, the gla- 

 cier retired continuously and rapidly. Above Chenango Bridge the river 

 found its old course blockaded and took a new course by Port Crane, the 

 railway still holding to the older and wider valley. The kames and 

 frontal terraces from Randallsville past Hamilton give evidence of much 

 ice and water action as we approach the principal moraine. The signifi- 

 cance of the latter has already been set forth. 



Summary. 



1. The ice retired with relative though not absolute rapidity from the 

 Chenango valley with several important pauses, but halted for massive 

 and prolonged work at the southern rim of the Mohawk basin. 



2. The easy southward gradient of the valley, more gentle then than 

 now, favored stagnation and led to much making of kame terraces. 



3. Such recession involved the presence of important ice-tongues, 

 whose length, thickness, and duration would form a fruitful theme for 

 further investigation. 



4. The moraines are of the kame type and generally are fronted by 

 terraces, some of which have true delta characters. 



5. Fskers have small place among the aqueo-glacial structures of the 

 region. 



6. The facts are unfavorable to the existence of deep and powerful 

 floods in the valley during the progress of melting, and an essentially 

 sectional manner of valley train accumulation is accepted for this region. 



7. Decided lacustrine conditions prevailed from near Binghamton to 

 the head of the valley for a long period. No opinion is offered as to the 

 precise structural and time relations of the deep clays to the other de- 

 posits described in this paper. It is believed that northern differential 

 depression and preglacial conditions of drainage yet undetermined are 

 important factors in the problem. 



