﻿Spencer 
  — 
  Origin 
  and 
  Age 
  of 
  the 
  Ontario 
  Shore-Line. 
  351 
  

  

  Art. 
  XXXII. 
  — 
  Origin 
  and 
  Age 
  of 
  the 
  Ontario 
  Shore-line, 
  

   — 
  Birth 
  of 
  the 
  Modern 
  Saint 
  Lawrence 
  River 
  ; 
  by 
  J. 
  W. 
  

   Spencer, 
  Ph.D., 
  LL.D. 
  

  

  Introduction. 
  — 
  The 
  modern 
  beach 
  of 
  Lake 
  Ontario 
  is 
  the 
  

   last 
  of 
  the 
  shore-lines 
  about 
  the 
  lake 
  basin 
  to 
  be 
  studied 
  with 
  

   sufficient 
  precision 
  for 
  writing 
  its 
  history, 
  although 
  seemingly 
  

   obvious. 
  Much 
  attention 
  had 
  been 
  given, 
  during 
  the 
  last 
  

   three 
  decades, 
  to 
  the 
  higher 
  water-planes, 
  especially 
  to 
  the 
  

   Iroquois 
  Beach 
  (of 
  Spencer*), 
  not 
  only 
  skirting 
  the 
  lake 
  at 
  a 
  

   high 
  level, 
  but 
  tilted 
  by 
  subsequent 
  earth-movements, 
  so 
  that 
  

   it 
  now 
  rises 
  540 
  feetf 
  between 
  the 
  head 
  of 
  the 
  lake 
  and 
  the 
  

   Galops 
  Rapids 
  of 
  the 
  St. 
  Lawrence 
  River 
  (66 
  miles 
  below 
  the 
  

   lake 
  outlet), 
  which 
  form 
  the 
  first 
  rocky 
  barrier 
  to 
  the 
  lake 
  

   basin. 
  In 
  contrast 
  with 
  this 
  deformation, 
  I 
  have 
  recently 
  de- 
  

   termined 
  the 
  horizon 
  tality 
  of 
  the 
  modern 
  shore. 
  J 
  In 
  sinking 
  

   from 
  the 
  higher 
  beach, 
  the 
  waters 
  fell 
  to 
  more 
  than 
  200 
  feet 
  

   below 
  the 
  present 
  level 
  (at 
  Niagara 
  River), 
  before 
  the 
  warping 
  

   of 
  the 
  earth's 
  crust 
  raised 
  the 
  barrier 
  to 
  the 
  lake 
  basin, 
  so 
  that 
  

   the 
  waters 
  rose 
  to 
  a 
  few 
  feet 
  above 
  the 
  present 
  Ontario 
  shore- 
  

   line, 
  from 
  which 
  they 
  have 
  since 
  been 
  lowered, 
  owing 
  to 
  the 
  

   scour 
  of 
  the 
  St. 
  Lawrence 
  River, 
  after 
  the 
  river 
  sunk 
  within 
  

   its 
  channel. 
  Pursuing 
  the 
  investigation 
  of 
  these 
  features, 
  

   with 
  the 
  aid 
  of 
  the 
  most 
  comprehensive 
  surveys, 
  soundings 
  and 
  

   borings 
  for 
  the 
  Toronto 
  Water 
  Supply, 
  especially 
  those 
  of 
  

   Messrs. 
  Chipman 
  and 
  Power, 
  I 
  have 
  been 
  able 
  to 
  approximate 
  

   the 
  age 
  of 
  the 
  present 
  shore-line 
  of 
  Lake 
  Ontario 
  and 
  that 
  of 
  

   the 
  St. 
  Lawrence 
  River. 
  

  

  Cessation 
  of 
  Earth- 
  Movements. 
  

   Birth 
  of 
  the 
  Post-Glacial 
  Saint 
  Lawrence 
  River. 
  

  

  Intermittent 
  subsiding 
  of 
  the 
  waters 
  below 
  the 
  Iroquois 
  

   Beach 
  is 
  seen 
  in 
  minor 
  beaches 
  and 
  terraces, 
  best 
  developed 
  in 
  

   the 
  valleys 
  tributary 
  to 
  that 
  of 
  the 
  lake. 
  Terraces 
  or 
  terrace- 
  

   plains 
  occur 
  at 
  70-75, 
  40, 
  15, 
  and 
  5 
  feet, 
  near 
  the 
  head 
  of 
  the 
  

   lake 
  and 
  along 
  the 
  lower 
  Niagara 
  River, 
  but 
  the 
  question 
  of 
  

   their 
  deformation 
  and 
  the 
  amount 
  of 
  lowering 
  of 
  the 
  lake 
  level 
  

  

  *" 
  Science," 
  vol. 
  ii, 
  p. 
  49, 
  1888 
  (abstract); 
  this 
  Journal, 
  vol. 
  xl, 
  pp. 
  445- 
  

   451, 
  1890. 
  

  

  f 
  Deformation 
  measured 
  between 
  head 
  of 
  lake 
  and 
  Watertown, 
  N. 
  Y., 
  is 
  

   367 
  feet, 
  and 
  calculated 
  to 
  the 
  Galops 
  Rapids 
  (where 
  the 
  country 
  is 
  low) 
  540 
  

   feet. 
  

  

  tBull. 
  Geol. 
  Soc. 
  Am., 
  vol. 
  xxvii, 
  p. 
  79, 
  1916 
  (abstract). 
  

  

  