﻿rll2 
  :new 
  YORK 
  state 
  museum 
  

  

  The 
  element 
  of 
  chance 
  seems 
  so 
  large 
  in 
  the 
  above 
  calculations^, 
  

   for 
  reasons 
  hitherto 
  stated, 
  that 
  they 
  must 
  be 
  taken 
  more 
  as 
  a 
  

   suggestion 
  than 
  as 
  a 
  statement 
  of 
  fact. 
  As 
  a 
  rule 
  however, 
  the- 
  

   figures 
  given 
  in 
  the 
  table 
  of 
  terraces 
  opposite 
  p. 
  r84, 
  indicate 
  a 
  

   prevailing 
  increase 
  in 
  elevation 
  to 
  the 
  north 
  for 
  the 
  different 
  lake 
  

   levels, 
  and 
  are, 
  the 
  writer 
  believes, 
  strongly 
  suggestive 
  of 
  a 
  change 
  

   in 
  level 
  of 
  the 
  shore-lines, 
  but 
  just 
  how 
  much 
  is 
  difficult 
  to 
  say. 
  

  

  SUMMARY 
  OF 
  CONCI.USIONS 
  

  

  All 
  evidence, 
  so 
  far 
  worked 
  out, 
  shows 
  the 
  ancestral 
  lake 
  history 
  

   in 
  the 
  post-glacial 
  development 
  of 
  the 
  present 
  lakes 
  to 
  be 
  a 
  rather 
  

   complex 
  one. 
  A 
  large 
  number 
  of 
  lake 
  stages 
  are 
  represented 
  with 
  

   many 
  outlets 
  differently 
  located. 
  Briefly 
  summarized, 
  this 
  paper 
  

   after 
  a 
  statement 
  of 
  the 
  preliminary 
  considerations 
  and 
  facts, 
  and 
  a 
  

   discussion 
  of 
  the 
  most 
  plausible 
  hypotheses^ 
  whereby 
  the 
  phenomena, 
  

   rnight 
  be 
  accounted 
  for, 
  has, 
  I 
  believe, 
  satisfactorily 
  eliminated 
  all 
  

   but 
  one 
  hypothesis. 
  This 
  one 
  successfully 
  meets 
  the 
  conditions 
  

   supplied 
  by 
  the 
  facts 
  and 
  conclusively 
  points 
  to 
  a 
  two-fold 
  lake 
  stage 
  

   in 
  the 
  Finger-lake 
  region. 
  The 
  facts 
  supporting 
  this 
  hy 
  pothesisy 
  

   briefly 
  stated, 
  are 
  

  

  1 
  Shore 
  lines, 
  (a) 
  Constructional 
  forms- 
  delta 
  terraces. 
  

  

  (b) 
  Some 
  probable 
  destruction 
  al 
  forms 
  cut 
  in 
  the 
  soft-till 
  

   deposits 
  which 
  are 
  in 
  part 
  resulting 
  modifications 
  probably 
  

   due 
  to 
  wave 
  action. 
  

  

  2 
  Overflow 
  channels. 
  

  

  3 
  Lacustrine 
  clays 
  and 
  silts. 
  

  

  4 
  Probable 
  iceberg 
  deposits. 
  

  

  When 
  the 
  ice 
  had 
  withdrawn 
  from 
  the 
  southern 
  divide 
  region,, 
  

   the 
  initial 
  stage 
  was 
  introduced, 
  or 
  that 
  of 
  local 
  lakes, 
  of 
  which 
  

   there 
  were 
  nearly 
  a 
  score 
  in 
  number. 
  These 
  local 
  lakes 
  filled 
  and 
  

   occupied 
  the 
  southern 
  portions 
  of 
  each 
  of 
  the 
  present 
  lake 
  valleys- 
  

   with 
  overflows 
  that 
  were 
  entirely 
  separate 
  from 
  and 
  independent 
  of 
  

   each 
  other. 
  

  

  A 
  general 
  lake 
  condition 
  immediately 
  succeeded 
  the 
  period 
  of 
  

   local 
  lakes 
  upon 
  a 
  farther 
  northerly 
  recession 
  of 
  the 
  ice, 
  when 
  the 
  

   local 
  lakes 
  coalesced 
  to 
  form 
  one 
  large 
  expanse 
  of 
  water, 
  closing 
  all 
  

   but 
  one 
  outlet 
  which 
  was 
  subsequently 
  shifted 
  to 
  different 
  parts 
  of 
  

  

  