﻿Lteelevation 
  of 
  the 
  St. 
  Lawrence 
  river 
  basin. 
  15 
  

  

  Indeed, 
  the 
  outflowing 
  river 
  from 
  Lakes 
  Iroquois, 
  Hudson- 
  

   Champlain, 
  and 
  St. 
  Lawrence, 
  or 
  the 
  Hudson 
  during 
  the 
  Post- 
  

   glacial 
  period, 
  channeled 
  the 
  lower 
  part 
  of 
  this 
  valley 
  to 
  a 
  

   depth 
  of 
  about 
  100 
  feet 
  below 
  the 
  present 
  sea 
  level, 
  proving 
  

   that 
  the 
  land 
  there, 
  as 
  Merrill 
  points 
  out, 
  stood 
  so 
  much 
  higher 
  

   than 
  now 
  at 
  some 
  time 
  after 
  the 
  ice 
  retreated. 
  

  

  According 
  to 
  the 
  observations 
  of 
  Davis, 
  Baldwin, 
  and 
  Baron 
  

   de 
  Geer, 
  the 
  highest 
  shore 
  line 
  of 
  the 
  Lake 
  Hndson-Cham 
  plain 
  

   is 
  now 
  elevated 
  to 
  about 
  275 
  feet 
  above 
  the 
  sea 
  at 
  Catskill, 
  1ST. 
  

   Y. 
  : 
  550 
  feet 
  in 
  Chesterfield, 
  N. 
  Y., 
  on 
  the 
  west 
  side 
  of 
  Lake 
  

   Champlain 
  opposite 
  to 
  Burlington 
  ; 
  and 
  658 
  feet 
  at 
  St. 
  Albans, 
  

   Vt. 
  Assuming 
  that 
  the 
  mouth 
  of 
  the 
  lake, 
  near 
  New 
  York 
  

   city, 
  was 
  50 
  feet 
  above 
  the 
  sea, 
  the 
  differential 
  northward 
  up- 
  

   lift 
  of 
  the 
  originally 
  level 
  shore 
  has 
  been 
  at 
  the 
  rate 
  of 
  about 
  

   two 
  feet 
  per 
  mile 
  for 
  the 
  100 
  miles 
  from 
  the 
  present 
  mouth 
  of 
  

   the 
  Hudson 
  to 
  Catskill 
  ; 
  1*7 
  feet 
  per 
  mile 
  for 
  the 
  next 
  160 
  

   miles 
  north 
  to 
  Chesterlield 
  ; 
  and 
  about 
  three 
  and 
  a 
  half 
  feet 
  

   per 
  mile 
  in 
  the 
  next 
  30 
  miles 
  north-northeastward 
  to 
  St. 
  

   Albans. 
  Perhaps 
  a 
  higher 
  beach 
  may 
  exist 
  in 
  Chesterfield, 
  

   which 
  would 
  bring 
  these 
  gradients 
  nearer 
  to 
  uniformity. 
  The 
  

   series 
  noted 
  there 
  by 
  Baldwin 
  comprises 
  eight 
  beaches 
  refera- 
  

   ble 
  to 
  the 
  successive 
  water 
  levels 
  of 
  Lake 
  Hudson-Champlain, 
  

   Lake 
  St. 
  Lawrence, 
  and 
  the 
  sea 
  in 
  the 
  Champlain 
  basin, 
  their 
  

   heights 
  above 
  the 
  sea 
  level 
  of 
  to-day 
  beino; 
  550 
  feet, 
  530, 
  470, 
  

   423, 
  386, 
  365, 
  335, 
  and 
  290 
  feet 
  The 
  mean 
  level 
  of 
  Lake 
  

   Champlain 
  is 
  97 
  feet 
  above 
  the 
  sea, 
  and 
  its 
  maximum 
  depth 
  

   402 
  feet. 
  The 
  lower 
  four 
  of 
  these 
  beaches 
  belonged 
  to 
  the 
  

   Champlain 
  arm 
  of 
  the 
  enlarged 
  Gulf 
  of 
  St. 
  Lawrence, 
  as 
  shown 
  

   by 
  the 
  height 
  of 
  its 
  sand 
  deltas 
  and 
  associated 
  fossiliferous 
  

   clays 
  ; 
  but 
  the 
  higher 
  four 
  represent 
  stages 
  of 
  the 
  Lakes 
  Hud- 
  

   son-Champlain 
  and 
  St. 
  Lawrence. 
  These 
  shore 
  lines, 
  like 
  

   those 
  of 
  the 
  glacial 
  lakes 
  farther 
  west 
  to 
  Lake 
  Agassiz, 
  were 
  

   probably 
  formed 
  during 
  times 
  of 
  rest 
  or 
  slackening 
  in 
  the 
  

   somewhat 
  intermittent 
  epeirogenic 
  elevation 
  of 
  the 
  land. 
  

  

  Lake 
  St. 
  Laiorence* 
  — 
  The 
  records 
  of 
  the 
  Glacial 
  and 
  Cham- 
  

   plain 
  epochs 
  in 
  the 
  St. 
  Lawrence 
  valley 
  have 
  been 
  most 
  fully 
  

   studied 
  during 
  many 
  years 
  by 
  Sir 
  William 
  Dawson, 
  to 
  whose 
  

   work 
  chiefly 
  we 
  are 
  indebted 
  for 
  detailed 
  descriptions 
  of 
  the 
  

   evidences 
  of 
  the 
  marine 
  submergence 
  of 
  that 
  region 
  to 
  a 
  maxi- 
  

  

  * 
  Sir 
  J. 
  William 
  Dawson, 
  The 
  Canadian 
  Ice 
  Age 
  (Montreal, 
  ]893), 
  p. 
  301, 
  with 
  

   maps 
  and 
  sections, 
  views 
  of 
  scenery, 
  and 
  nine 
  plates 
  of 
  Pleistocene 
  fossils. 
  This 
  

   volume 
  sums 
  up 
  the 
  author's 
  work 
  since 
  1855 
  on 
  the 
  glacial 
  drift 
  and 
  associated 
  

   lacustrine 
  and 
  Champlain 
  marine 
  formations 
  of 
  the 
  St. 
  Lawrence 
  valley, 
  embody- 
  

   ing 
  the 
  studies 
  which 
  had 
  been 
  published 
  in 
  many 
  papers 
  in 
  the 
  "Canadian 
  

   Naturalist 
  and 
  Geologist 
  " 
  and 
  elsewhere. 
  He 
  had 
  given 
  a 
  similar 
  summary 
  in 
  a 
  

   pamphlet 
  of 
  112 
  pages, 
  " 
  Notes 
  on 
  the 
  Post-pliocene 
  of 
  Canada." 
  in 
  1872. 
  J. 
  W. 
  

   SpeDcer. 
  G-. 
  K. 
  Gilbert, 
  Baron 
  de 
  Geer, 
  S. 
  Prentiss 
  Baldwin, 
  and 
  Warren 
  Upham, 
  

   as 
  before 
  cited 
  for 
  Lakes 
  Warren, 
  Algonquin, 
  Iroquois, 
  and 
  Hudson-Champlain. 
  

  

  