﻿126 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  and 
  northwesterly 
  out 
  of 
  the 
  Adirondack 
  region,- 
  and 
  southerly 
  

   and 
  southwesterly 
  out 
  of 
  the 
  Canadian 
  Precambric 
  region, 
  and 
  

   these 
  streams 
  diverted 
  by 
  the 
  large 
  subsequent 
  streams 
  in 
  the 
  

   Black 
  river, 
  St 
  Lawrence 
  and 
  Ontario 
  valleys 
  ; 
  the 
  Black 
  along 
  

   the 
  overlap 
  of 
  the 
  sedimentaries 
  on 
  the 
  crystallines, 
  the 
  Ontario 
  

   valley 
  on 
  the 
  thick 
  shales, 
  and 
  the 
  St 
  Lawrence 
  on 
  the 
  limestones 
  

   of 
  the 
  depressed 
  trough, 
  with 
  bordering 
  Potsdam 
  and 
  Precambric 
  

   on 
  both 
  sides; 
  hence 
  each 
  on 
  a 
  relatively 
  weak 
  rock 
  belt. 
  In 
  

   these 
  positions 
  the 
  Tertiary 
  successors 
  dug 
  out 
  their 
  valleys. 
  

   They 
  mostly 
  flowed 
  as 
  they 
  do 
  now, 
  the 
  important 
  exception 
  be- 
  

   ing 
  in 
  the 
  case 
  of 
  the 
  Ontario-St 
  Lawrence 
  drainage. 
  The 
  fold, 
  

   or 
  warp, 
  of 
  the 
  Frontenac 
  axis 
  crosses 
  this 
  drainage 
  line 
  in 
  our 
  

   district. 
  Even 
  before 
  being 
  worn 
  down 
  to 
  the 
  Precambric 
  this 
  

   would 
  make 
  a 
  natural 
  rock 
  barrier 
  to 
  the 
  drainage, 
  since 
  the 
  

   lower 
  Ordovicic 
  rocks 
  are 
  more 
  resistant 
  than 
  the 
  upper, 
  and 
  

   hence 
  form 
  a 
  divide 
  or 
  col 
  between 
  waters 
  flowing 
  northeast, 
  

   down 
  the 
  present 
  St 
  Lawrence 
  valley, 
  and 
  waters 
  passing 
  west 
  

   through 
  the 
  Ontario 
  valley, 
  the 
  Black 
  river 
  forming 
  the 
  chief 
  

   stream 
  of 
  the 
  immediate 
  region, 
  as 
  it 
  now 
  does. 
  All 
  writers 
  on 
  

   the 
  district 
  have 
  considered 
  that, 
  in 
  Tertiary 
  times, 
  the 
  Black 
  

   river 
  turned 
  westward 
  into 
  the 
  Ontario 
  valley. 
  Wilson 
  espe- 
  

   cially 
  has 
  considered 
  the 
  drainage 
  of 
  the 
  immediate 
  region 
  in 
  

   some 
  detail 
  in 
  a 
  most 
  excellent 
  paper, 
  with 
  m.uch 
  of 
  which 
  we 
  

   are 
  in 
  entire 
  agreement.' 
  He 
  points 
  out 
  that 
  the 
  St 
  Lawrence 
  

   lacks 
  a 
  definite 
  channel 
  in 
  the 
  Thousand 
  Island 
  region, 
  going 
  

   over 
  the 
  Frontenac 
  axis 
  at 
  its 
  most 
  depressed 
  point. 
  With 
  this 
  

   we 
  agree, 
  but 
  we 
  do 
  not 
  coincide 
  with 
  his 
  view 
  that 
  the 
  Black 
  

   river, 
  in 
  its 
  course 
  across 
  the 
  mapped 
  area, 
  is 
  closely 
  in 
  its 
  

   preglacial 
  channel 
  (the 
  river 
  below 
  Carthage 
  is 
  here 
  referred 
  

   to). 
  We 
  are 
  however 
  in 
  doubt 
  as 
  to 
  where 
  this 
  preglacial 
  chan- 
  

   nel 
  was. 
  Fairchild 
  disagrees 
  entirely 
  with 
  the 
  view 
  that 
  the 
  

   preglacial 
  waters 
  of 
  the 
  Black 
  river 
  went 
  westward, 
  and 
  turns 
  

   them 
  into 
  the 
  St 
  Lawrence 
  valley 
  below 
  the 
  col. 
  His 
  views 
  are. 
  

   presented 
  on 
  pages 
  141-145. 
  I 
  dissent 
  somewhat, 
  preferring 
  the 
  

   view 
  that 
  the 
  drainage 
  went 
  into 
  the 
  Ontario 
  basin, 
  but 
  must 
  

   frankly 
  admit 
  that 
  I 
  have 
  not 
  discovered 
  the 
  precise 
  route 
  fol- 
  

   lowed, 
  so 
  that 
  it 
  seems 
  to 
  me 
  that 
  opinion 
  in 
  the 
  matter 
  must 
  

   be 
  held 
  in 
  abeyance, 
  pending 
  discovery 
  of 
  the 
  actual 
  old 
  channel. 
  

   If 
  the 
  Frontenac 
  axis 
  formed 
  a 
  divide 
  here 
  in 
  Tertiary 
  times 
  

   such 
  divide 
  should 
  run 
  across 
  our 
  district 
  toward 
  the 
  Adiron- 
  

   dacks, 
  as 
  a 
  divide 
  between 
  streams 
  going 
  north 
  and 
  those 
  moving 
  

  

  iGeol. 
  Soc. 
  Am. 
  Bui. 
  15:236-42. 
  

  

  