﻿138 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  the 
  plain 
  at 
  Watertown 
  was 
  200-250 
  feet, 
  at 
  Lafargeville 
  about 
  

   350 
  feet, 
  and 
  OA^er 
  the 
  plains 
  at 
  Chippewa 
  Bay 
  about 
  550 
  feet. 
  

  

  Eventually 
  the 
  ice 
  barrier 
  weakened 
  in 
  the 
  St 
  Lawrence 
  valley 
  and 
  

   the 
  Iroquois 
  waters 
  found 
  a 
  new 
  outlet 
  north 
  of 
  the 
  Adiron- 
  

   dacks 
  which 
  was 
  lower 
  (at 
  that 
  time) 
  than 
  the 
  old 
  outlet 
  south 
  

   of 
  the 
  Adirondacks 
  by 
  the 
  Mohawk 
  valley. 
  One 
  point 
  of 
  escape 
  

   was 
  the 
  '' 
  Covey 
  Hill 
  gulf," 
  precisely 
  on 
  the 
  international 
  bound- 
  

   ary 
  between 
  New 
  York 
  and 
  Canada, 
  about 
  4 
  miles 
  northeast 
  of 
  

   Clinton 
  Mills. 
  ^ 
  The 
  Covey 
  gulf 
  is 
  a 
  great 
  V-shaped 
  gorge 
  in 
  hard 
  

   Potsdam 
  sandstone, 
  leading 
  north 
  of 
  east, 
  and 
  it 
  carried 
  the 
  waters 
  

   of 
  the 
  second 
  stage 
  of 
  Iroquois, 
  or 
  the 
  Hypoiroquois, 
  over 
  to 
  some 
  

   lower 
  level 
  in 
  the 
  Champlain 
  basin. 
  From 
  aneroid 
  measurements 
  

   it 
  is 
  estimated 
  that 
  the 
  altitude 
  of 
  the 
  head 
  of 
  the 
  gulf 
  is 
  about 
  

   850 
  feet, 
  or 
  perhaps 
  somewhat 
  higher, 
  but 
  when 
  the 
  gulf 
  was 
  made 
  

   the 
  district 
  was 
  at 
  least 
  460 
  feet 
  lower 
  than 
  it 
  is 
  today, 
  and 
  must 
  

   have 
  been 
  lower 
  than 
  the 
  Rome 
  outlet, 
  which 
  is 
  now 
  430 
  feet. 
  It 
  

   appears 
  that 
  the 
  Covey 
  gulf 
  outlet 
  was 
  not 
  much 
  lower 
  that 
  the 
  

   Rome 
  outlet, 
  perhaps 
  50 
  feet 
  and 
  possibly 
  100 
  feet. 
  It 
  might 
  seem 
  

   as 
  if 
  the 
  Covey 
  gulf 
  outlet 
  represented 
  sufficient 
  length 
  of 
  time 
  

   for 
  the 
  lake 
  waters 
  at 
  that 
  level 
  to 
  produce 
  recognizable 
  features 
  

   along 
  favorable 
  stretches 
  of 
  the 
  shore 
  line, 
  and 
  such 
  may 
  yet 
  be 
  

   found. 
  Dr 
  Gilbert 
  has 
  suggested 
  that 
  possibly 
  the 
  Covey 
  gulf 
  was 
  

   chiefly 
  cut 
  by 
  a 
  more 
  ancient 
  glacial 
  outflow 
  and 
  that 
  the 
  Hypo- 
  

   iroquois 
  may 
  have 
  done 
  little 
  work 
  beyond 
  clearing 
  out 
  the 
  old 
  gorge. 
  

  

  As 
  the 
  ice 
  front 
  melted 
  back 
  this 
  second 
  stage 
  of 
  the 
  glacial 
  

   waters 
  of 
  the 
  Ontario 
  basin 
  found 
  yet 
  lower 
  escape 
  along 
  the 
  north 
  

   side 
  of 
  Covey 
  hill, 
  between 
  the 
  ice 
  wall 
  and 
  the 
  rock 
  slope. 
  This 
  

   third 
  phase 
  of 
  the 
  Iroquois 
  waters 
  must 
  have 
  been 
  short-lived, 
  with 
  

   rapidly 
  falling 
  levels, 
  the 
  river 
  flow 
  only 
  terracing 
  the 
  sandstone 
  

   slope. 
  It 
  is 
  thought 
  that 
  the 
  final 
  effect 
  of 
  this 
  down-draining 
  of 
  

   the 
  glacial 
  waters 
  was 
  to 
  bring 
  them 
  into 
  confluence 
  with 
  the 
  oceanic 
  

   waters 
  which 
  then 
  occupied 
  the 
  Champlain 
  basin 
  and 
  are 
  called 
  

   the 
  Champlain 
  (Woodworth's 
  Hochelagan) 
  sea. 
  The 
  supposed 
  ex- 
  

   tension 
  of 
  the 
  sea-level 
  waters 
  into 
  the 
  Ontario 
  basin 
  is 
  known 
  as 
  

   Gilbert 
  gulf.^ 
  

  

  Gilbert 
  gulf. 
  If 
  our 
  present 
  conception 
  of 
  the 
  history 
  is 
  

   correct 
  the 
  sea-level 
  waters 
  covered 
  nearly 
  all 
  the 
  territory 
  

   comprised 
  in 
  our 
  five 
  quadrangles. 
  On 
  the 
  north 
  slope 
  of 
  

   Covey 
  hill 
  the 
  Champlain 
  beaches 
  have 
  an 
  altitude 
  of 
  at 
  least 
  

   460 
  feet, 
  which 
  is 
  the 
  measure 
  of 
  the 
  amount 
  of 
  land 
  uplift 
  in 
  

  

  1 
  For 
  description 
  and 
  illustrations 
  of 
  this 
  outlet 
  see 
  paper 
  by 
  J. 
  B. 
  Wood- 
  

   worth, 
  Ancient 
  Water 
  Levels. 
  N. 
  Y. 
  State 
  Mus. 
  Bui. 
  84. 
  Ebenezer 
  Emmons 
  

   and 
  G. 
  K. 
  Gilbert 
  had 
  noted 
  the 
  feature. 
  

  

  2 
  Gilbert 
  Gulf 
  (Marine 
  Waters 
  in 
  Ontario 
  Basin). 
  Fairchild, 
  H. 
  L. 
  Geo], 
  

   Soc 
  Am. 
  Bui. 
  17:712-18. 
  

  

  