﻿rl06 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  strongest 
  shore 
  markings 
  should 
  exist, 
  where 
  the 
  time 
  existence 
  of 
  

   tlie 
  lake 
  was 
  the 
  most 
  protracted. 
  In 
  applying 
  this 
  principle 
  to 
  the 
  

   valleys 
  in 
  question 
  we 
  find 
  very 
  close 
  agreement. 
  

  

  The 
  most 
  pronounced 
  and 
  typical 
  class 
  of 
  terraces 
  is 
  found 
  in 
  the 
  

   southern 
  portions 
  of 
  each 
  of 
  the 
  existing 
  lake 
  valleys, 
  where 
  the 
  

   lake 
  endured 
  the 
  longest. 
  As 
  we 
  travel 
  northward 
  the 
  terraces 
  

   very 
  rapidly 
  grow 
  fainter 
  and 
  less 
  pronounced, 
  until 
  near 
  the 
  north- 
  

   ern 
  valley 
  extremities 
  they 
  are 
  lost 
  altogether, 
  no 
  record 
  of 
  this 
  

   character 
  being 
  left 
  to 
  mark 
  the 
  history. 
  An 
  element 
  which 
  has 
  

   attended 
  the 
  development 
  of 
  the 
  stronger 
  terraces 
  in 
  the 
  southern 
  

   parts 
  of 
  the 
  valleys, 
  is 
  that 
  the 
  most 
  vigorous 
  streams 
  are 
  confined 
  

   for 
  the 
  most 
  part 
  to 
  this 
  zone. 
  While 
  this 
  is 
  recognized 
  to 
  be 
  one 
  

   of 
  the 
  prime 
  factors 
  in 
  terrace 
  growth, 
  the 
  terraces 
  in 
  the 
  Finger-lake 
  

   valleys 
  do 
  not 
  rigidly 
  adhere 
  to 
  the 
  size 
  of 
  the 
  parent 
  stream, 
  hence, 
  

   the 
  other 
  factors 
  concerned 
  must 
  in 
  some 
  cases 
  have 
  been 
  of 
  equal 
  if 
  

   not 
  greater 
  import 
  in 
  thus 
  regulating 
  the 
  growth 
  of 
  the 
  abandoned 
  

   delta 
  terraces. 
  A 
  prominent 
  element 
  thns 
  concerned 
  in 
  this 
  region, 
  

   and 
  elsewhere 
  noted 
  by 
  workers 
  on 
  glacial 
  dammed 
  lakes, 
  is 
  the 
  fol- 
  

   lowing 
  : 
  the 
  farther 
  removed 
  from 
  the 
  northernmost 
  extension 
  of 
  

   the 
  ice 
  while 
  damming 
  the 
  waters 
  (provided, 
  of 
  course, 
  the 
  block- 
  

   ing 
  occurs 
  in 
  a 
  north 
  and 
  south 
  valley 
  with 
  a 
  northward 
  ice 
  reces- 
  

   sion), 
  the 
  more 
  accentuated 
  are 
  the 
  terraces 
  ; 
  lake 
  depth, 
  of 
  course, 
  

   being 
  always 
  an 
  important 
  factor. 
  In 
  other 
  words, 
  terrace 
  accentu- 
  

   ation 
  is 
  commensurate 
  with 
  lake 
  life. 
  

  

  A 
  study 
  of 
  the 
  table 
  of 
  terraces 
  opposite 
  p. 
  r84: 
  shows 
  at 
  a 
  glance 
  

   that 
  while 
  the 
  terraces 
  admit 
  of 
  fairly 
  good 
  correlation 
  they 
  are 
  not 
  

   found 
  at 
  the 
  exact 
  elevation 
  for 
  the 
  same 
  level 
  on 
  each 
  stream, 
  but 
  

   vary 
  between 
  certain 
  admissible 
  limits. 
  Their 
  location 
  in 
  case 
  of 
  

   Cayuga 
  and 
  Seneca 
  valleys 
  as 
  well 
  as 
  the 
  remaining 
  Finger-lake 
  

   valleys, 
  is 
  certainly 
  most 
  unfavorable 
  for 
  maintaining 
  their 
  correlative 
  

   heights 
  throughout. 
  

  

  Discussion 
  of 
  the 
  lower 
  terraces 
  

  

  Lower 
  ten-aces 
  occur 
  at 
  successive 
  elevations 
  on 
  all 
  of 
  the 
  streams 
  

   from 
  which 
  the 
  higher 
  levels 
  have 
  been 
  noted 
  and 
  discussed. 
  Not 
  

   only 
  are 
  they 
  found 
  on 
  the 
  same 
  streams 
  with 
  the 
  higher 
  terraces, 
  

   but 
  also 
  on 
  a 
  large 
  number 
  along 
  which 
  the 
  higher 
  levels 
  have 
  not 
  

   been 
  found. 
  Wherever 
  streams 
  of 
  any 
  size 
  enter 
  the 
  lakes, 
  this 
  

  

  