﻿THE 
  GEOLOGICAL 
  HISTORY 
  OF 
  NEW 
  YORK 
  STATE 
  27 
  

  

  point 
  in 
  the 
  lake 
  basin. 
  Thus 
  the 
  streams 
  in 
  the 
  western 
  portion 
  

   of 
  this 
  drainage 
  'basin 
  flow 
  north 
  to 
  northeastward, 
  northward 
  in 
  

   the 
  middle 
  portion, 
  and 
  westward 
  to 
  northwestward 
  in 
  the 
  eastern 
  

   portion. 
  Three 
  rivers 
  should 
  be 
  mentioned 
  : 
  the 
  Genesee, 
  with 
  

   its 
  source 
  in 
  the 
  highlands 
  of 
  Pennsylvania, 
  flows 
  northward 
  across 
  

   the 
  entire 
  southwestern 
  plateau 
  ; 
  the 
  Oswego, 
  toward 
  the 
  middle 
  of 
  

   the 
  basin, 
  takes 
  one 
  arm 
  (Seneca 
  river) 
  from 
  the 
  west 
  to 
  drain 
  the 
  

   large 
  Finger 
  lakes 
  and 
  another 
  arm 
  from 
  the 
  east 
  to 
  drain 
  Oneida 
  

   lake 
  and 
  part 
  of 
  the 
  Tug 
  Hill 
  plateau 
  ; 
  Black 
  river 
  drains 
  the 
  extreme 
  

   eastern 
  portion 
  of 
  the 
  basin, 
  and 
  a 
  number 
  of 
  prominent 
  tributaries 
  

   flow 
  southwestward 
  from 
  well 
  within 
  the 
  Adirondacks 
  to 
  join 
  the 
  

   main 
  stream 
  in 
  the 
  great 
  Black 
  river 
  valley. 
  

  

  Susquehanna 
  basin. 
  All 
  the 
  waters 
  of 
  the 
  Susquehanna 
  river 
  

   are 
  derived 
  from 
  the 
  Southwestern 
  plateau. 
  The 
  main 
  stream 
  

   (within 
  New 
  York) 
  flows 
  southwestward 
  and 
  together 
  with 
  its 
  

   numerous 
  large 
  tributaries 
  drains 
  much 
  of 
  the 
  eastern 
  portion 
  of 
  

   the 
  plateau 
  region, 
  especially 
  in 
  Otsego 
  county. 
  A 
  number 
  of 
  the 
  

   tributaries 
  rise 
  on 
  the 
  very 
  crest 
  of 
  the 
  Helderberg 
  escarpment 
  and 
  

   within 
  a 
  few 
  miles 
  of 
  the 
  Mohawk 
  river. 
  The 
  Mohawk 
  river 
  is 
  

   fully 
  a 
  thousand 
  feet 
  below 
  the 
  crest 
  of 
  Ihe 
  escarpment, 
  and 
  its 
  

   course 
  is 
  at 
  right 
  angles 
  to 
  that 
  of 
  Susquehanna 
  tributaries. 
  

  

  The 
  Chemung 
  is 
  the 
  principal 
  tributary 
  from 
  the 
  northwest 
  and 
  

   drains 
  a 
  good 
  portion 
  of 
  the 
  south-central 
  plateau. 
  

  

  Other 
  drainage 
  basins. 
  The 
  Champlain 
  basin 
  comprises 
  the 
  

   eastern 
  border 
  of 
  the 
  Adirondacks, 
  including 
  some 
  of 
  the 
  highest 
  

   and 
  most 
  rugged 
  of 
  those 
  mountains. 
  Nearly 
  all 
  the 
  streams 
  are 
  

   short 
  and 
  most 
  of 
  them 
  descend 
  eastward 
  very 
  rapidly 
  into 
  Lake 
  

   Champlain. 
  

  

  The 
  Delaware, 
  by 
  means 
  of 
  its 
  upper 
  waters, 
  drains 
  the 
  western 
  

   and 
  southern 
  Catskills 
  and 
  the 
  main 
  stream, 
  after 
  flowing 
  south- 
  

   eastward 
  along 
  the 
  State 
  line 
  between 
  New 
  York 
  and 
  Pennsylvania, 
  

   from 
  Delaware 
  county 
  to 
  Orange 
  county, 
  suddenly 
  swings 
  south- 
  

   westward 
  to 
  pass 
  through 
  the 
  famous 
  Delaware 
  water 
  gap 
  in 
  the 
  

   Kitatinny 
  range. 
  

  

  The 
  Allegheny 
  river 
  sends 
  out 
  a 
  number 
  of 
  small 
  branching 
  arms 
  

   to 
  drain 
  the 
  extreme 
  southwestern 
  portion 
  of 
  the 
  Southwestern 
  

   plateau. 
  Chautauqua 
  lake 
  (elevation 
  1338 
  feet) 
  which 
  lies 
  at 
  the 
  

   very 
  western 
  edge 
  of 
  the 
  plateau 
  and 
  close 
  to 
  Lake 
  Erie, 
  has 
  its 
  

   outlet 
  into 
  the 
  Allegheny. 
  

  

  The 
  Erie 
  basin 
  contains 
  no 
  river 
  of 
  much 
  consequence, 
  the 
  small 
  

   streams 
  all 
  flowing 
  westward 
  or 
  northwestward 
  across 
  the 
  narrow 
  

   Erie 
  plain 
  and 
  into 
  Lake 
  Erie 
  or 
  the 
  Niagara 
  river. 
  Nearly 
  all 
  

  

  