﻿12 
  W. 
  Upham 
  — 
  Champlain 
  Subsidence 
  and 
  

  

  the 
  richly 
  fossiliferous 
  Leda 
  clays, 
  which 
  last 
  overlie 
  the 
  latest 
  

   glacial 
  drift 
  in 
  the 
  St. 
  Lawrence, 
  Ottawa, 
  and 
  Cham 
  plain 
  

   valleys, 
  may 
  be 
  referred 
  to 
  the 
  closing 
  stage 
  or 
  Champlain 
  

   epoch 
  of 
  the 
  Ice 
  age 
  ; 
  and 
  they 
  both 
  testify, 
  like 
  the 
  partially 
  

   forest-covered 
  Malaspina 
  ice-sheet 
  in 
  Alaska, 
  of 
  the 
  close 
  

   sequence 
  of 
  a 
  warm 
  climate, 
  with 
  luxuriant 
  plant 
  and 
  animal 
  

   life, 
  during 
  and 
  immediately 
  after 
  the 
  recession 
  of 
  the 
  ice- 
  

   sheet. 
  The 
  transition 
  from 
  the 
  GTlacial 
  to 
  the 
  Champlain 
  

   climate 
  seems 
  readily 
  explained 
  by 
  the 
  epeirogenic 
  depression 
  

   which 
  ended 
  the 
  Glacial 
  period.* 
  

  

  The 
  height 
  of 
  Lake 
  Ontario 
  is 
  247 
  feet 
  ; 
  and 
  that 
  of 
  the 
  old 
  

   Iroquois 
  outlet 
  crossing 
  the 
  water-shed 
  at 
  Rome 
  is 
  440 
  feet, 
  

   above 
  the 
  sea 
  level. 
  Thence 
  the 
  Iroquois 
  beach 
  in 
  its 
  course 
  

   northward 
  adjacent 
  to 
  the 
  eastern 
  end 
  of 
  Lake 
  Ontario 
  has 
  a 
  

   gradual 
  ascent 
  of 
  about 
  five 
  feet 
  per 
  mile 
  along 
  a 
  distance 
  of 
  

   55 
  miles 
  to 
  the 
  latitude 
  of 
  Watertown, 
  where 
  the 
  highest 
  

   beach 
  is 
  730 
  feet 
  above 
  the 
  sea, 
  showing 
  that 
  a 
  differential 
  up- 
  

   lift 
  of 
  about 
  290 
  feet 
  has 
  taken 
  place, 
  in 
  comparison 
  with 
  the 
  

   Rome 
  outlet. 
  From 
  Rome 
  westward 
  to 
  Rochester, 
  the 
  beach 
  

   has 
  nearly 
  the 
  same 
  height 
  with 
  the 
  outlet 
  ; 
  but 
  farther 
  west- 
  

   ward 
  it 
  descends 
  to 
  385 
  feet 
  above 
  the 
  sea 
  at 
  Lewiston 
  and 
  363 
  

   feet 
  at 
  Hamilton, 
  at 
  the 
  western 
  end 
  of 
  Lake 
  Ontario. 
  Con- 
  

   tinuing 
  along 
  the 
  beach 
  north 
  of 
  the 
  lake, 
  the 
  same 
  elevation 
  

   as 
  the 
  Rome 
  outlet 
  is 
  reached 
  near 
  Toronto, 
  and 
  thence 
  east- 
  

   northeastward 
  an 
  uplift 
  is 
  found, 
  similar 
  to 
  that 
  before 
  

   described 
  east 
  of 
  the 
  lake, 
  its 
  amount 
  near 
  Trenton 
  and 
  Belle- 
  

   ville 
  above 
  Rome 
  being 
  about 
  240 
  feet 
  It 
  is 
  to 
  be 
  added 
  that 
  

   northward 
  from 
  Rome 
  the 
  Iroquois 
  beach 
  becomes 
  divided 
  

   into 
  a 
  series 
  of 
  distinct 
  beaches, 
  marking 
  stages 
  in 
  the 
  north- 
  

   eastward 
  rise 
  of 
  the 
  land 
  and 
  having 
  near 
  Watertown 
  a 
  verti- 
  

   cal 
  range 
  of 
  80 
  feet 
  below 
  the 
  highest 
  and 
  oldest, 
  which 
  was 
  

   before 
  noted 
  ; 
  and 
  that 
  westward 
  a 
  similar 
  series 
  of 
  strand 
  

   lines 
  also 
  lies 
  below 
  the 
  highest, 
  likewise 
  before 
  noted, 
  which 
  

   there, 
  however, 
  contrary 
  to 
  the 
  order 
  northeastward, 
  was 
  the 
  

   newest. 
  The 
  highest 
  beach 
  near 
  Watertown 
  was 
  probably 
  

   contemporaneous 
  with 
  the 
  fossiliferous 
  beds 
  of 
  Toronto 
  ; 
  some 
  

   of 
  the 
  intermediate 
  northeastern 
  beaches 
  corresponded 
  to 
  the 
  

   delta 
  deposits 
  of 
  Scarboro 
  ; 
  and 
  the 
  lowest 
  northeastward 
  lake 
  

   level 
  was 
  continuous 
  with 
  the 
  highest 
  at 
  Toronto, 
  Hamilton^ 
  

   Lewiston, 
  and 
  east 
  to 
  Rome. 
  

  

  Between 
  Lakes 
  Warren 
  and 
  Lundy 
  the 
  old 
  water 
  level 
  near 
  

   the 
  west 
  end 
  of 
  Lake 
  Ontario 
  fell 
  125 
  feet, 
  minus 
  some 
  amount 
  

   to 
  be 
  subtracted 
  for 
  the 
  progressing 
  northeastward 
  elevation 
  

   of 
  the 
  land. 
  The 
  two 
  Lundy 
  shores 
  are 
  30 
  feet 
  apart 
  verti- 
  

  

  * 
  J. 
  D. 
  Dana, 
  Trans. 
  Conn. 
  Acad, 
  of 
  Arts 
  and 
  Sciences, 
  vol. 
  ii, 
  1870, 
  p. 
  67; 
  

   this 
  Journal, 
  III, 
  vol. 
  x, 
  pp. 
  168-183, 
  Sept., 
  1875. 
  Warren 
  Upham, 
  G-lacialists' 
  

   Magazine, 
  vol. 
  i, 
  pp. 
  236-240, 
  June, 
  1894. 
  

  

  