﻿66 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Fluvial 
  period 
  

  

  Niagara 
  falls 
  came 
  into 
  existence 
  when 
  the 
  waters 
  of 
  Lake 
  Iro- 
  

   quois, 
  the 
  predecessor 
  of 
  Lake 
  Ontario, 
  fell 
  beneath 
  the 
  level 
  of 
  the 
  

   escarpment 
  at 
  Lewiston. 
  At 
  first 
  it 
  was 
  only 
  a 
  small 
  cataract, 
  but 
  

   day 
  by 
  day, 
  as 
  the 
  lake 
  subsided, 
  it 
  gained 
  in 
  hight 
  and 
  consequently 
  

   in 
  force 
  of 
  fall, 
  as 
  well 
  as 
  efficiency 
  in 
  cutting 
  its 
  channel. 
  That 
  the 
  

   entire 
  gorge 
  from 
  Lewiston 
  to 
  the 
  present 
  falls 
  is 
  the 
  product 
  of 
  

   river 
  erosion 
  is 
  scarcely 
  questioned 
  by 
  any 
  one 
  today, 
  but 
  there 
  are 
  

   excellent 
  reasons 
  which 
  lead 
  some 
  to 
  believe 
  that 
  this 
  cutting 
  was 
  

   not 
  wholly 
  the 
  work 
  of 
  the 
  Niagara. 
  When 
  the 
  falls 
  were 
  at 
  Lewis- 
  

   ton, 
  the 
  Niagara 
  was 
  a 
  placid 
  stream 
  from 
  Lake 
  Erie 
  to 
  near 
  the 
  

   falls, 
  much 
  as 
  it 
  is 
  today 
  from 
  Buffalo 
  to 
  the 
  northern 
  end 
  of 
  Grand 
  

   island. 
  Its 
  banks 
  consisted 
  chiefly 
  of 
  glacial 
  till, 
  into 
  which 
  terraces 
  

   were 
  cut 
  by 
  the 
  stream, 
  most 
  of 
  which 
  are 
  visible 
  at 
  the 
  present 
  day. 
  

   The 
  lower 
  ones 
  are 
  well 
  marked 
  in 
  Prospect 
  park, 
  though 
  there 
  

   they 
  have 
  been 
  grassed 
  over 
  and 
  modified 
  to 
  a 
  considerable 
  extent. 
  

   From 
  Niagara 
  falls 
  to 
  the 
  railroad 
  bridges 
  at 
  Suspension 
  Bridge, 
  on 
  

   the 
  New 
  York 
  side 
  of 
  the 
  river, 
  the 
  old 
  bank 
  runs 
  parallel 
  to 
  the 
  

   edge 
  of 
  the 
  gorge 
  and 
  at 
  a 
  short 
  distance 
  inland 
  from 
  this. 
  From 
  

   Suspension 
  Bridge 
  to 
  the 
  whirlpool 
  it 
  makes 
  a 
  curve 
  somewhat 
  more 
  

   crescentic 
  than 
  that 
  of 
  the 
  margin 
  of 
  the 
  gorge, 
  and 
  a 
  similar 
  curve 
  

   from 
  the 
  whirlpool 
  to 
  Bloody 
  run 
  at 
  the 
  Devil's 
  hole. 
  On 
  the 
  Can- 
  

   adian 
  side 
  these 
  'old 
  river 
  banks 
  can 
  be 
  traced 
  from 
  above 
  the 
  falls 
  

   almost 
  to 
  Brock's 
  monument, 
  and 
  in 
  some 
  cases 
  two 
  or 
  three 
  suc- 
  

   cessive 
  terraces 
  are 
  recognizable. 
  In 
  Queen 
  Victoria 
  park 
  they 
  

   constitute 
  the 
  steep 
  slope 
  which 
  bounds 
  the 
  park 
  on 
  the 
  west, 
  and 
  

   parts 
  of 
  which 
  are 
  still 
  actively 
  eroded. 
  Less 
  than 
  a 
  mile 
  below 
  

   the 
  carriage 
  bridge, 
  the 
  old 
  banks 
  approach 
  close 
  to 
  the 
  modern 
  

   one 
  and 
  continue, 
  almost 
  coincident 
  with 
  it, 
  to 
  the 
  railway 
  bridges 
  

   at 
  Clifton. 
  From 
  here 
  to 
  the 
  whirlpool 
  the 
  old 
  river 
  margin 
  has 
  a 
  

   nearly 
  straight 
  course, 
  while 
  the 
  modern 
  one 
  is 
  curved, 
  and 
  a 
  similar 
  

   relation 
  holds 
  below 
  the 
  whirlpool, 
  though 
  here, 
  from 
  the 
  great 
  

   curvature 
  of 
  the 
  modern 
  channel, 
  the 
  old 
  banks 
  are 
  in 
  places 
  nearly 
  

   a 
  mile 
  distant.^ 
  (Plate 
  6) 
  

  

  ^These 
  old 
  river 
  banks 
  are 
  indicated 
  on 
  the 
  geologic 
  map 
  by 
  dotted 
  

   lines; 
  the 
  localities 
  where 
  shells 
  have 
  been 
  found 
  are 
  shown 
  by 
  crosses. 
  

  

  