﻿270 
  F 
  B. 
  Taylor 
  — 
  Niagara 
  and 
  the 
  Great 
  Takes. 
  

  

  Lakes. 
  They 
  are 
  set 
  down 
  in 
  seven 
  principal 
  stages 
  with 
  

   transitions 
  or 
  critical 
  stages 
  between. 
  

  

  I. 
  Glacial, 
  ice-dammed 
  lakes. 
  Outlets 
  at 
  Fort 
  Wayne, 
  

   Chicago 
  and 
  other 
  places. 
  Beaches 
  correlated 
  with 
  moraines 
  

   in 
  Ohio. 
  Glacial 
  lakes 
  fall 
  by 
  stages 
  as 
  outlets 
  change 
  on 
  

   withdrawal 
  of 
  the 
  glacier-dams. 
  Land 
  relatively 
  high 
  in 
  the 
  

   north 
  but 
  slowly 
  subsiding. 
  

  

  First 
  Transition 
  : 
  By 
  withdrawal 
  of 
  glacier 
  the 
  Niagara 
  

   river 
  is 
  opened 
  and 
  the 
  upper 
  lakes 
  become 
  united. 
  

  

  II. 
  First 
  Niagara 
  lakes. 
  First 
  epoch 
  of 
  Niagara 
  Falls 
  

   begins 
  at 
  Lewiston. 
  For 
  a 
  short 
  time 
  glacial 
  Lake 
  Iroquois 
  

   receives 
  the 
  water 
  from 
  Niagara. 
  Shore 
  lines 
  of 
  lower 
  levels 
  

   of 
  this 
  glacial 
  lake 
  washed 
  over 
  and 
  obliterated 
  by 
  later 
  marine 
  

   invasion. 
  Gradual 
  depression 
  of 
  land 
  continues 
  at 
  north, 
  

   finally 
  opening 
  Nipissing 
  outlet. 
  

  

  Second 
  Transition: 
  First 
  two-outlet 
  climax. 
  Marked 
  by 
  

   the 
  Algonquin 
  Beach. 
  (Possible 
  subdivision 
  here 
  for 
  sup- 
  

   posed 
  Trent 
  river 
  outlet.) 
  Gradual 
  northward 
  depression 
  con- 
  

   tinues. 
  First 
  epoch 
  of 
  Niagara 
  Falls 
  closes 
  at 
  the 
  Whirlpool. 
  

   Epoch 
  of 
  Erigan 
  Fall 
  begins. 
  

  

  III. 
  First 
  Lake 
  Algonquin. 
  Outlet 
  eastward 
  over 
  Nipis- 
  

   sing 
  pass. 
  

  

  Third 
  Transition: 
  Gradual 
  northward 
  depression 
  con- 
  

   tinues. 
  Nipissing 
  outlet 
  brought 
  down 
  to 
  sea 
  level. 
  Lakes 
  

   become 
  marine. 
  

  

  IV. 
  Warren 
  Gulf 
  (rising 
  stage). 
  Marine 
  waters 
  fill 
  the 
  

   three 
  upper 
  lakes, 
  the 
  Ontario, 
  St. 
  Lawrence 
  and 
  Winnipeg 
  

   basins. 
  

  

  Fourth 
  Transition 
  : 
  Marine 
  climax. 
  Marked 
  by 
  the 
  Chip- 
  

   pewa 
  Beach. 
  Northward 
  depression 
  ceases 
  and 
  gradual 
  eleva- 
  

   tion 
  begins. 
  Iroquois 
  and 
  Herman 
  marine 
  beaches 
  made 
  at 
  

   the 
  same 
  time 
  as 
  the 
  Chippewa. 
  This 
  was 
  probably 
  the 
  climax 
  

   of 
  the 
  post-glacial 
  warm 
  epoch. 
  

  

  V. 
  Warren 
  Gulf 
  (falling 
  stage). 
  Gradual 
  northward 
  eleva- 
  

   tion. 
  Irregular 
  uplifts 
  in 
  the 
  north 
  deforming 
  Chippewa 
  and 
  

   Algonquin 
  beaches. 
  

  

  Fifth 
  Transition 
  : 
  Nipissing 
  outlet 
  raised 
  to 
  sea 
  level. 
  

   Upper 
  lakes 
  become 
  fresh. 
  

  

  VI. 
  Second 
  Lake 
  Algonquin. 
  Outlet 
  eastward 
  over 
  Nipis- 
  

   sing 
  pass. 
  Probably 
  a 
  small 
  amount 
  of 
  local 
  uplift 
  at 
  outlet 
  

   in 
  early 
  stage. 
  

  

  /Sixth 
  Transition 
  : 
  Second 
  two-outlet 
  climax. 
  Marked 
  by 
  

   the 
  Nipissing 
  Beach. 
  Epoch 
  of 
  Erigan 
  Fail 
  closes 
  at 
  a 
  point 
  

   between 
  40 
  and 
  80 
  rods 
  above 
  the 
  cantilever 
  bridge. 
  Second 
  

   (present) 
  epoch 
  of 
  Niagara 
  Falls 
  begins. 
  

  

  VII. 
  Second 
  Niagara 
  lakes 
  (present 
  stage). 
  Lake 
  Superior 
  

   becomes 
  independent. 
  Great 
  Champlain 
  uplift 
  at 
  the 
  north- 
  

   east. 
  Formation 
  of 
  St. 
  Clair 
  delta 
  begins 
  and 
  continues 
  to 
  the 
  

   present 
  time. 
  

  

  Fort 
  Wayne, 
  Ind., 
  Feb'y 
  18, 
  1895. 
  

  

  