﻿FOURTH 
  REPORT 
  OF 
  THE 
  DIRECTOR 
  t.qOj 
  19 
  

  

  The 
  shores 
  of 
  Lake 
  Champlain 
  about 
  its 
  northern 
  end 
  seem 
  in 
  

   places 
  to 
  be 
  higher 
  than 
  when 
  the 
  cliffs 
  were 
  cut. 
  The 
  evidence 
  

   from 
  many 
  parts 
  of 
  the 
  shore 
  is 
  not 
  conclusive 
  for 
  or 
  against 
  

   changes 
  of 
  level, 
  either 
  a 
  rising 
  or 
  a 
  sinking. 
  Such 
  channels 
  as 
  that 
  

   from 
  Champlain 
  village 
  suggest 
  a 
  rising 
  of 
  the 
  water 
  level. 
  It 
  is 
  

   probable 
  that 
  the 
  highly 
  tilted 
  Siluric 
  slates 
  in 
  Vermont 
  are 
  being 
  

   crowded 
  up 
  and 
  that 
  downward 
  movements 
  have 
  been 
  taking 
  place 
  

   among 
  the 
  faulted 
  rocks 
  of 
  the 
  New 
  York 
  shore 
  along 
  the 
  Inter- 
  

   national 
  border. 
  

  

  Western, 
  central 
  and 
  northwestern 
  New 
  York. 
  As 
  a 
  result 
  

   of 
  Professor 
  Fairchild's 
  investigations 
  the 
  story 
  of 
  the 
  succession 
  

   of 
  glacial 
  waters 
  in 
  western, 
  central 
  and 
  northern 
  New 
  York 
  is 
  

   approaching 
  completion. 
  Following 
  several 
  introductory 
  and 
  pre- 
  

   liminary 
  papers, 
  the 
  glacial 
  waters 
  held 
  in 
  the 
  Lake 
  Erie 
  basin 
  in 
  

   this 
  State 
  have 
  been 
  described 
  in 
  State 
  Museum 
  bulletin 
  106. 
  The 
  

   later 
  waters 
  in 
  central 
  New 
  York 
  down 
  to 
  the 
  Iroquois 
  stage 
  are 
  

   described 
  in 
  the 
  paper 
  awaiting 
  publication. 
  Lake 
  Iroquois 
  is 
  well 
  

   known 
  in 
  its 
  general 
  character 
  and 
  history, 
  but 
  there 
  yet 
  remains 
  

   for 
  description 
  : 
  ( 
  i 
  ) 
  the 
  local 
  glacial 
  lakes 
  held 
  in 
  the 
  valleys 
  of 
  

   the 
  western 
  and 
  northern 
  Adirondacks 
  during 
  the 
  Iroquois 
  stage; 
  

   (2) 
  the 
  extinction 
  of 
  Lake 
  Iroquois; 
  (3) 
  the 
  sea 
  level 
  waters 
  which 
  

   occupied 
  the 
  Ontario 
  basin 
  subsequent 
  to 
  Lake 
  Iroquois 
  and 
  pre- 
  

   ceding 
  the 
  present 
  Lake 
  Ontario. 
  The 
  past 
  summer's 
  work 
  has 
  

   been 
  on 
  these 
  three 
  elements 
  of 
  the 
  history, 
  and 
  is 
  briefly 
  summa- 
  

   rized 
  in 
  the 
  following 
  description. 
  

  

  (1) 
  Local 
  glacial 
  lakes. 
  All 
  the 
  well 
  defined 
  valleys 
  sloping 
  west- 
  

   ward 
  or 
  northward 
  from 
  the 
  Adirondack 
  mass 
  must 
  have 
  held 
  

   glacial 
  .waters 
  while 
  the 
  ice 
  acted 
  as 
  a 
  barrier. 
  The 
  largest 
  and 
  

   most 
  interesting 
  of 
  these 
  local 
  lakes 
  was 
  the 
  one 
  in 
  the 
  Black 
  river 
  

   valley, 
  which 
  in 
  all 
  the 
  elements 
  concerned 
  in 
  the 
  functions 
  and 
  

   relationship 
  of 
  such 
  waters 
  is 
  the 
  most 
  excellent 
  known 
  in 
  the 
  State. 
  

   The 
  larger 
  part 
  of 
  the 
  summer 
  was 
  used 
  in 
  the 
  study 
  of 
  this 
  lake, 
  

   and 
  its 
  description 
  will 
  form 
  the 
  subject 
  of 
  a 
  future 
  paper. 
  

  

  (2) 
  Iroquois 
  extinction. 
  A 
  broad 
  ridge 
  of 
  Potsdam 
  sandstone 
  

   extending 
  north 
  from 
  the 
  Adirondacks 
  into 
  Canada 
  forms 
  the 
  divide 
  

   between 
  the 
  Champlain 
  and 
  Ontario 
  basins 
  and 
  is 
  the 
  critical 
  area 
  

   in 
  this 
  study. 
  A 
  rapid 
  examination 
  of 
  the 
  divide 
  shows 
  that 
  the 
  

   Iroquois 
  waters 
  were 
  held 
  up 
  to 
  the 
  Rome 
  outlet 
  until 
  the 
  south 
  

   edge 
  of 
  the 
  ice 
  body 
  had 
  receded 
  as 
  far 
  north 
  as 
  the 
  International 
  

   boundary, 
  but 
  that 
  here 
  the 
  waters 
  found 
  lower 
  escape 
  across 
  Covey 
  

   hill, 
  the 
  north 
  end 
  of 
  the 
  ridge. 
  The 
  outflow 
  here 
  cut 
  the 
  great 
  

  

  