GEOLOGY OF THE NORTHERN ADIRONDACK REGION 441 



faults downthrowing to the east, as most of the proved faults 

 of northern New York are, it is more likely that the surface 

 tilting would be to the west. It would also seem that the 

 streams down the fault scarp would fyave an advantage over 

 those down the back slope, because of their much steeper grades, 

 and that originally the main tributaries would be westerly flow- 

 ing streams down the back slopes, but that the streams down 

 the scarp would lengthen at the expense of the others, pushing 

 the divides westward. If now the main streams are at succes- 

 sively lower levels going eastward because of step faulting, 

 these easterly tributaries would have that additional great ad- 

 vantage over those flowing west, and would not only tend to 

 extend themselves at the expense of the westerly streams, but 

 also to work back to, and to tap and lead off portions of the 

 larger streams to the westward. Inspection of the maps shows 

 many such apparent captures of the main streams by the east- 

 erly tributaries. If the writer be correct in his belief that these 

 are the main structural features of the region, the assumption 

 of the abnormal easterly tilting of the fault blocks seems un- 

 necessary. 



The great and abnormal bends to the northeast which are 

 made by both the Hudson and the Sacandaga, some 15 miles to 

 25 miles north of the Mohawk line, would seem to be wholly 

 modern and owing to glacial action. As a result of this swerve, 

 no stream of respectable size enters the Mohawk eastward from 

 East Canada creek, the drainage all turning east to the Hudson, 

 while the divide between the streams flowing south to the 

 Mohawk and those passing east into the Hudson, parallels the 

 Mohawk and is distant from it only 15 to 18 miles. These 

 features are excellently shown on the new, small scale topo- 

 graphic map of the State and strongly suggest a mora.inic divide, 

 and that the Sacandaga formerly came down to the Mohawk in 

 the Amsterdam region. The modern stream which flows north- 

 eastward from Gloversville and empties into the Sacandaga at 

 the big bend, would seem to occupy this valley. Obviously a 

 considerable shifting of divides must take place here in the near 

 future, the present arrangement being highly unstable. 



Chamberlin long since urged that the preglacial divide or col 

 in the Mohawk lowland, between the drainage east to the Hudson 



