﻿64 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  course 
  had 
  a 
  uniform 
  elevation 
  while 
  forming, 
  are 
  no 
  longer 
  of 
  uni- 
  

   form 
  hight 
  above 
  sealevel, 
  but 
  rise 
  progressively 
  toward 
  the 
  north- 
  

   east. 
  This 
  slow 
  rising 
  of 
  the 
  land 
  caused 
  a 
  gradual 
  canting 
  of 
  the 
  

   basins, 
  which 
  brought 
  vvath 
  it 
  a 
  relative 
  fall 
  of 
  the 
  waters 
  along 
  the 
  

   northeastern 
  shores 
  and 
  a 
  corresponding 
  relative 
  rise 
  of 
  the 
  waters 
  

   along 
  the 
  southwestern 
  shores. 
  Such 
  a 
  progressive 
  change 
  event- 
  

   ually 
  carried 
  the 
  Nipissing 
  and 
  Balsam 
  lake 
  outlets 
  above 
  the 
  level 
  

   of 
  the 
  outlet 
  at 
  Port 
  Huron, 
  and 
  the 
  present 
  drainage 
  was 
  reestab- 
  

   lished. 
  As 
  the 
  canting 
  affected 
  the 
  Erie 
  basin 
  as 
  well 
  as 
  the 
  others^ 
  

   it 
  caused 
  a 
  progressive 
  elongation 
  of 
  that 
  lake 
  toward 
  the 
  south- 
  

   west, 
  thus 
  finally 
  giving 
  it 
  its 
  present 
  size 
  and 
  shape. 
  This 
  same 
  

   canting 
  also 
  resulted 
  in 
  the 
  farther 
  separation 
  of 
  the 
  upper 
  lakes 
  into 
  

   their 
  present 
  divisions. 
  

  

  While 
  this 
  general 
  outline 
  of 
  the 
  lake 
  history 
  is 
  held 
  by 
  many 
  

   geologists, 
  others, 
  notably 
  Upham, 
  combat 
  it 
  strongly. 
  Mr 
  Upham 
  

   holds 
  that 
  the 
  elevation 
  of 
  the 
  land 
  in 
  the 
  northeast 
  had 
  progressed 
  

   to 
  such 
  an 
  extent 
  by 
  the 
  time 
  the 
  ice 
  had 
  uncovered 
  the 
  northern 
  

   outlets 
  of 
  Lakes 
  Algonquin 
  and 
  Nipissing, 
  that 
  these 
  passes 
  had 
  

   been 
  raised 
  above 
  the 
  altitude 
  of 
  the 
  outlet 
  at 
  Port 
  Huron, 
  and 
  that 
  

   hence 
  these 
  passes 
  never, 
  or 
  but 
  for 
  a 
  brief 
  period 
  of 
  time, 
  served 
  

   as 
  outlets 
  for 
  the 
  waters 
  of 
  the 
  upper 
  lakes. 
  If 
  this 
  is 
  the 
  case, 
  

   Niagara 
  always 
  carried 
  the 
  drainage 
  of 
  the 
  upper 
  great 
  lakes 
  as 
  well 
  

   as 
  Lake 
  Erie, 
  and 
  its 
  volume 
  was 
  approximately 
  uniform 
  throughout 
  

   its 
  history. 
  The 
  strong 
  erosion 
  features, 
  however, 
  which 
  are 
  found 
  

   in 
  the 
  Mattawa 
  valley 
  indicate 
  that 
  a 
  large 
  stream 
  discharged 
  here 
  for 
  

   a 
  considerable 
  period 
  of 
  time; 
  and, 
  if 
  such 
  was 
  the 
  case, 
  it 
  is 
  highly 
  

   probable 
  that 
  the 
  present 
  Port 
  Huron 
  outlet 
  was 
  not 
  then 
  utilized^ 
  

   and 
  that 
  consequently 
  the 
  Niagara 
  was 
  robbed 
  of 
  the 
  discharge 
  of 
  

   the 
  upper 
  lake 
  area. 
  The 
  influence 
  on 
  the 
  erosion 
  of 
  the 
  gorge 
  by 
  

   such 
  a 
  withdrawal 
  of 
  the 
  water 
  must 
  have 
  been 
  a 
  pronounced 
  one, 
  

   and 
  we 
  shall 
  see 
  later 
  that 
  certain 
  portions 
  of 
  the 
  gorge 
  may 
  well 
  be 
  

   explained 
  by 
  this 
  hypothesis. 
  During 
  the 
  time 
  of 
  the 
  overflow 
  of 
  

   the 
  upper 
  waters 
  by 
  way 
  of 
  the 
  Nipissing-Mattawa 
  river 
  it 
  is 
  not 
  

   improbable 
  that, 
  as 
  held 
  by 
  Taylor 
  and 
  others, 
  the 
  sea 
  had 
  access, 
  

   to 
  the 
  St 
  Lawrence 
  and 
  Ontario 
  basins 
  and 
  possibly 
  to 
  the 
  basins 
  of 
  

   the 
  upper 
  lakes. 
  This 
  would 
  account 
  for 
  the 
  occurrence 
  of 
  marine 
  

   types 
  of 
  organisms 
  in 
  the 
  deeper 
  portions 
  of 
  some 
  of 
  the 
  present 
  

  

  