﻿FOURTH 
  REPORT 
  OF 
  THE 
  DIRECTOR 
  1907 
  6j 
  

  

  the 
  river 
  flow 
  must 
  have 
  been 
  inferior 
  to 
  the 
  Rome 
  level, 
  which 
  is 
  

   now 
  440 
  feet. 
  

  

  After 
  at 
  least 
  many 
  centuries 
  of 
  flow 
  this 
  predecessor 
  of 
  the 
  

   St 
  Lawrence 
  river, 
  carrying 
  the 
  overflow 
  of 
  the 
  second 
  stage 
  of 
  

   Iroquois 
  waters 
  (or 
  Hypo-Iroquois), 
  was 
  extinguished 
  by 
  the 
  ice 
  

   recession 
  opening 
  a 
  yet 
  lower 
  pass, 
  on 
  the 
  north 
  slope 
  of 
  Covey 
  

   hill. 
  This 
  third 
  phase 
  of 
  the 
  Iroquois 
  waters 
  was 
  short-lived 
  and 
  

   of 
  rapidly 
  falling 
  levels, 
  the 
  river 
  flow 
  past 
  the 
  ice 
  front 
  only 
  terrac- 
  

   ing 
  the 
  sandstone 
  slope. 
  

  

  When 
  the 
  waters 
  were 
  lowered 
  about 
  450 
  feet 
  below 
  the 
  Gulf 
  

   channel, 
  they 
  became 
  confluent 
  with 
  the 
  oceanic 
  waters, 
  and 
  the 
  

   Ontario 
  basin 
  was 
  occupied 
  by 
  the 
  Gilbert 
  gulf, 
  a 
  branch 
  of 
  the 
  

   Champlain 
  or 
  Hochelagan 
  sea. 
  

  

  On 
  Friday 
  the 
  parties 
  from 
  Mooers 
  and 
  Plattsburg 
  met 
  at 
  Chazy 
  

   where 
  Professor 
  Cushing 
  and 
  Dr 
  Ruedemann 
  showed 
  the 
  visiting 
  

   geologists 
  many 
  interesting 
  features 
  of 
  the 
  Chazy 
  limestone, 
  the 
  

   local 
  succession 
  of 
  beds, 
  the 
  characteristic 
  fossils, 
  the 
  faults, 
  and 
  the 
  

   dissection 
  which 
  have 
  produced 
  the 
  present 
  topography. 
  After 
  

   supper, 
  while 
  waiting 
  for 
  the 
  train 
  to 
  Plattsburg, 
  the 
  party 
  sat 
  on 
  

   the 
  hotel 
  porch 
  and 
  listened 
  to 
  a 
  talk 
  by 
  Dr 
  R. 
  Ruedemann 
  on 
  

  

  The 
  Lower 
  Siluric 
  paleogeography 
  of 
  the 
  Champlain 
  basin 
  

  

  The 
  relations 
  of 
  the 
  faunas 
  of 
  the 
  Beekmantown, 
  Fort 
  Cassin, 
  

   Chazy, 
  Black 
  River, 
  Trenton, 
  and 
  Utica 
  beds 
  to 
  those 
  of 
  the 
  At- 
  

   lantic 
  and 
  Pacific 
  basins 
  and 
  the 
  Mississippian 
  sea 
  were 
  discussed, 
  

   and 
  by 
  means 
  of 
  these 
  relations 
  the 
  probable 
  marine 
  connections 
  of 
  

   the 
  Chazy 
  basin 
  and 
  the 
  Levis 
  channel 
  with 
  the 
  oceanic 
  basins 
  traced. 
  

   It 
  was 
  suggested 
  that 
  the 
  Beekmantown 
  sea, 
  while 
  extending 
  as 
  far 
  

   as 
  the 
  Newfoundland 
  embayment, 
  held 
  an 
  American 
  epicontinental 
  

   fauna; 
  that 
  the 
  Fort 
  Cassin 
  fauna 
  did 
  not 
  reach 
  Canada, 
  but 
  

   flourished 
  in 
  the 
  Appalachian 
  trough 
  to 
  the 
  south 
  of 
  the 
  Chazy 
  

   basin, 
  and 
  also 
  spread 
  westward 
  into 
  the 
  epicontinental 
  sea. 
  The 
  

   typical 
  Chazy 
  fauna 
  is 
  thus 
  far 
  recorded 
  only 
  for 
  the 
  Chazy 
  basin 
  

   and 
  the 
  southern 
  Appalachian 
  trough. 
  It 
  extended 
  as 
  far 
  as 
  the 
  

   Mingan 
  islands, 
  and 
  came 
  probably 
  from 
  the 
  Atlantic 
  basin. 
  There 
  

   is 
  also 
  evidence 
  that 
  it 
  had 
  some 
  connection 
  with 
  the 
  American 
  

   epicontinental 
  sea. 
  

  

  The 
  Black 
  River 
  and 
  Trenton 
  faunas, 
  while 
  largely 
  American 
  in 
  

   their 
  aspects, 
  contain 
  European 
  species 
  as 
  the 
  first 
  of 
  the 
  Lower 
  

   Siluric; 
  and 
  the 
  connection 
  of 
  the 
  Trenton 
  sea 
  with 
  the 
  Atlantic 
  

   ocean 
  can 
  not 
  be 
  doubted. 
  In 
  Utica 
  time 
  the 
  channel 
  became 
  so 
  

  

  