﻿F 
  B. 
  Taylor 
  — 
  Niagara 
  and 
  the 
  Great 
  Lakes. 
  261 
  

  

  ward 
  from 
  Long 
  Island 
  Sound 
  is 
  about 
  100 
  feet 
  deep, 
  and 
  the 
  

   continental 
  shelf 
  all 
  along 
  slopes 
  seaward. 
  In 
  order 
  to 
  make 
  a 
  

   land 
  barrier 
  for 
  the 
  water 
  in 
  the 
  Hudson 
  valley 
  it 
  is 
  necessary 
  

   to 
  suppose 
  a 
  southward 
  differential 
  elevation 
  of 
  more 
  than 
  200 
  

   feet 
  50 
  miles 
  south 
  of 
  New 
  York 
  and 
  of 
  100 
  feet 
  off 
  Montauk 
  

   Point. 
  But 
  there 
  is 
  no 
  evidence 
  of 
  such 
  an 
  amount 
  of 
  eleva- 
  

   tion, 
  still 
  less 
  is 
  there 
  any 
  evidence 
  of 
  differential 
  rise 
  to 
  the 
  

   south. 
  The 
  supposed 
  post-Champlain 
  elevation 
  100 
  feet 
  higher 
  

   than 
  at 
  present 
  at 
  New 
  York 
  and 
  later 
  re-submergence 
  to 
  the 
  

   same 
  amount, 
  for 
  which 
  Merrill 
  offers 
  some 
  evidence, 
  can 
  not 
  

   serve 
  Mr. 
  Upham's 
  purpose. 
  For 
  the 
  glacial 
  lake, 
  if 
  it 
  ever 
  

   existed, 
  was 
  long 
  before 
  the 
  time 
  of 
  the 
  Cham 
  plain 
  submer- 
  

   gence.* 
  

  

  The 
  hypothesis 
  of 
  a 
  southward 
  land 
  barrier 
  of 
  this 
  ice- 
  

   dammed 
  lake 
  seems 
  to 
  me 
  to 
  be 
  in 
  the 
  face 
  of 
  the 
  plain 
  read- 
  

   ing 
  of 
  the 
  facts. 
  The 
  simplest 
  interpretation 
  is 
  most 
  likely 
  to 
  

   be 
  true 
  and 
  in 
  this 
  case 
  it 
  is 
  that 
  the 
  Hudson-Champlain 
  

   trough 
  was 
  occupied 
  at 
  the 
  highest 
  stage 
  of 
  submergence 
  by 
  

   marine 
  waters 
  which 
  connected 
  with 
  the 
  Laurentian 
  Gulf 
  of 
  

   that 
  time. 
  And 
  this 
  did 
  not 
  follow 
  closely 
  upon 
  the 
  retreat 
  of 
  

   the 
  ice, 
  but 
  came 
  at 
  a 
  time 
  long 
  after. 
  

  

  But 
  if 
  the 
  sea 
  filled 
  the 
  Hudson-Champlain 
  trough, 
  attaining 
  

   a 
  height 
  of 
  700 
  feetf 
  or 
  more 
  at 
  the 
  north 
  end 
  of 
  Lake 
  Cham- 
  

   plain 
  it 
  is 
  impossible 
  to 
  avoid 
  the 
  inference 
  that 
  this 
  was 
  the 
  

   time 
  of 
  the 
  formation 
  of 
  the 
  Iroquois, 
  Chippewa 
  and 
  Herman 
  

   beaches. 
  Considering 
  the 
  very 
  recent 
  occurrence 
  of 
  the 
  Cham- 
  

   plain 
  uplift 
  the 
  absence 
  of 
  fossils 
  in 
  the 
  much 
  older, 
  higher 
  

   deposits 
  can 
  hardly 
  be 
  regarded 
  as 
  an 
  important 
  consider- 
  

   ation 
  in 
  determining 
  the 
  character 
  of 
  those 
  deposits. 
  

  

  The 
  First 
  Lake 
  Algonquin. 
  

  

  The 
  first 
  Lake 
  Algonquin 
  was 
  a 
  post-glacial 
  lake 
  occupying 
  

   the 
  basins 
  of 
  the 
  three 
  upper 
  lakes 
  and 
  having 
  its 
  outlet 
  east- 
  

   ward 
  over 
  the 
  Nipissing 
  pass. 
  Its 
  area 
  was 
  a 
  little 
  larger 
  than 
  

   that 
  of 
  the 
  second 
  Lake 
  Algonquin, 
  for 
  its 
  shores 
  are 
  higher 
  

   at 
  all 
  places 
  save 
  one 
  at 
  the 
  head 
  of 
  the 
  St. 
  Clair 
  river, 
  where 
  

   both 
  planes 
  come 
  to 
  one 
  level. 
  

  

  The 
  history 
  of 
  the 
  second 
  Lake 
  Algonquin 
  and 
  the 
  deforma- 
  

   tion 
  of 
  the 
  Nipissing 
  plane 
  are 
  fully 
  discussed 
  in 
  the 
  paper 
  of 
  

   that 
  title 
  referred 
  to 
  above. 
  The 
  facts 
  at 
  present 
  in 
  hand 
  

   relating 
  to 
  that 
  lake 
  are 
  much 
  more 
  numerous 
  than 
  those 
  

  

  * 
  The 
  very 
  recent 
  date 
  of 
  the 
  uplift 
  that 
  brought 
  this 
  submergence 
  to 
  a 
  close 
  

   is 
  shown 
  in 
  the 
  paper 
  on 
  the 
  second 
  Lake 
  Algonquin 
  ; 
  and 
  the 
  lateness 
  of 
  the 
  

   submergence 
  itself 
  is 
  readily 
  inferred 
  from 
  the 
  sequence 
  of 
  lake 
  stages 
  set 
  forth 
  

   below. 
  

  

  f 
  I 
  found 
  well 
  formed 
  beach 
  ridges 
  at 
  660 
  feet 
  near 
  West 
  Chazy, 
  N. 
  Y., 
  with 
  

   less 
  certain 
  marks 
  of 
  submergence 
  up 
  to 
  about 
  800 
  feet. 
  

  

  