﻿THE 
  GEOLOGICAL 
  HISTORY 
  OF 
  NEW 
  YORK 
  STATE 
  

  

  99 
  

  

  from 
  Whittlesey 
  was 
  westward 
  by 
  a 
  large 
  river 
  flowing 
  through 
  

   small 
  Lake 
  Saginaw 
  and 
  into 
  Lake 
  Chicago, 
  which 
  latter 
  still 
  

   emptied 
  through 
  the 
  Illinois 
  river. 
  

  

  At 
  a 
  still 
  later 
  stage 
  (figure 
  32) 
  Lake 
  Saginaw 
  merged 
  with 
  the 
  

   waters 
  of 
  the 
  Erie 
  basin 
  to 
  form 
  the 
  large 
  Lake 
  Warren 
  which 
  

   extended 
  along 
  the 
  ice 
  front 
  eastward 
  nearly 
  to 
  central 
  New 
  York. 
  

   As 
  the 
  map 
  clearly 
  shows, 
  the 
  Finger 
  lakes 
  basins 
  of 
  New 
  York 
  

   were 
  then 
  occupied 
  by 
  Warren 
  waters, 
  while 
  Niagara 
  Falls 
  were 
  

   not 
  then 
  in 
  existence 
  because 
  that 
  region 
  was 
  also 
  covered 
  by 
  Lake 
  

   Warren. 
  Lake 
  Warren 
  continued 
  to 
  discharge 
  westward 
  into 
  Lake 
  

   Chicago 
  and 
  the 
  Mississippi 
  river 
  until 
  a 
  very 
  late 
  stage, 
  when 
  the 
  

   waters 
  had 
  worked 
  their 
  way 
  along 
  the 
  border 
  of 
  the 
  Ontario 
  ice 
  

  

  Fig. 
  32 
  Glacial 
  Lake 
  Warren. 
  At 
  this 
  stage 
  the 
  discharge 
  of 
  the 
  lake 
  

   was 
  still 
  westward 
  to 
  Lake 
  Chicago 
  and 
  the 
  Mississippi 
  river, 
  while 
  the 
  east- 
  

   ern 
  end 
  of 
  the 
  lake 
  covered 
  most 
  of 
  the 
  Finger 
  Lakes 
  region 
  of 
  New 
  York. 
  

  

  Modified 
  from 
  Taylor 
  & 
  Leverett, 
  U. 
  S. 
  G. 
  S. 
  

  

  lobe 
  into 
  the 
  Mohawk 
  valley 
  which 
  was 
  then 
  occupied 
  by 
  a 
  large 
  

   glacial 
  lake 
  (held 
  up 
  by 
  the 
  Ontario 
  ice 
  lobe 
  on 
  the 
  west 
  and 
  the 
  

   Champlain-Hudson 
  lobe 
  on 
  the 
  east) 
  and 
  thence 
  into 
  the 
  Hud- 
  

   son 
  valley. 
  Thus, 
  for 
  the 
  first 
  time, 
  the 
  Great 
  Lakes 
  drainage 
  

   passed 
  eastward 
  into 
  the 
  Atlantic 
  ocean. 
  This 
  great 
  volume 
  of 
  

   water 
  draining 
  eastward 
  was 
  often 
  in 
  the 
  form 
  of 
  distinct 
  streams 
  

   with 
  the 
  ice 
  front 
  for 
  north 
  wall 
  and 
  the 
  high 
  land 
  of 
  the 
  Helder- 
  

   berg 
  escarpment 
  for 
  wall 
  on 
  the 
  south. 
  Many 
  of 
  these 
  glacial 
  

   stream 
  channels, 
  which 
  are 
  still 
  plainly 
  visible, 
  have 
  been 
  studied 
  

   and 
  mapped 
  by 
  Professor 
  Fairchild. 
  

  

  