﻿REPORT 
  OF 
  THE 
  DIRECTOR 
  r75 
  

  

  the 
  variation 
  being 
  in 
  degree 
  of 
  development 
  wliicli 
  is 
  not 
  very 
  

   great, 
  and 
  not 
  in 
  kind. 
  

  

  While 
  the 
  various 
  overflows 
  have 
  attained 
  a 
  rather 
  conspicuous 
  

   degree 
  of 
  development, 
  they 
  have 
  been 
  lowered 
  by 
  erosion 
  but 
  a 
  

   few 
  feet 
  at 
  most 
  in 
  the 
  soft 
  glacial 
  deposits. 
  The 
  channel-ways 
  

   seem 
  to 
  suggest 
  a 
  uniform 
  rate 
  of 
  erosion, 
  since 
  the 
  deposits 
  in 
  

   which 
  they 
  have 
  been 
  sunk 
  are 
  apparently 
  homogeneous 
  throughout 
  

   and 
  not 
  blocked 
  or 
  interspersed 
  with 
  bowlder 
  belts. 
  In 
  no 
  instance 
  

   has 
  any 
  portion 
  of 
  the 
  respective 
  channels 
  cut 
  through 
  the 
  till 
  into 
  the 
  

   underlying 
  shale, 
  with 
  the 
  single 
  exception 
  of 
  apart 
  of 
  the 
  Spencer 
  

   Summit 
  outlet. 
  This 
  fact 
  tends 
  to 
  lend 
  strength 
  to 
  the 
  argu- 
  

   ment 
  favoring 
  a 
  short 
  life 
  history 
  for 
  the 
  numerous 
  lake 
  stages 
  

   among 
  the 
  higher 
  levels 
  of 
  the 
  Finger-lakes. 
  Such 
  a 
  condition 
  

   might 
  result 
  from 
  an 
  overl)urdemng 
  of 
  the 
  channels. 
  This 
  w^ould 
  

   be 
  especially 
  applicable 
  to 
  the 
  incipient 
  lake 
  stages, 
  before 
  the 
  ice 
  

   had 
  withdrawn 
  vej*y 
  far 
  northward 
  from 
  the 
  divide 
  region. 
  From 
  

   what 
  follows 
  in 
  the 
  subsequent 
  parts 
  of 
  this 
  paper, 
  it 
  would 
  hardl}- 
  

   seem 
  that 
  overburdening 
  continued 
  throughout 
  the 
  ice 
  retreat, 
  as 
  

   the 
  lake 
  extent 
  would 
  certainly 
  modify 
  and 
  check 
  this 
  condition. 
  

  

  Shore 
  features 
  in 
  the 
  finger-lake 
  valleys 
  

  

  Constructional 
  shore-lines. 
  On 
  nearly 
  evevy 
  one 
  of 
  the 
  streams 
  

   which 
  was 
  tributary 
  to 
  these 
  valleys 
  in 
  preglacial 
  times 
  is 
  

   marked 
  a 
  series 
  of 
  well 
  developed 
  delta 
  terraces, 
  the 
  highest 
  

   ones 
  averasfins: 
  above 
  the 
  100"> 
  foot 
  contour. 
  Thev 
  are 
  found 
  at 
  

   different 
  elevations 
  from 
  the 
  highest 
  down 
  to 
  those 
  forming 
  at 
  the 
  

   mouths 
  of 
  the 
  streams 
  entering 
  the 
  lakes 
  at 
  present. 
  In 
  many 
  

   instances, 
  however, 
  they 
  are 
  absent 
  from 
  some 
  areas, 
  where, 
  judging 
  

   from 
  present 
  indication.^, 
  conditions 
  would 
  certainly 
  have 
  favored 
  

   their 
  development. 
  Why 
  they 
  were 
  not 
  recorded 
  seems 
  difficult 
  to 
  

   explain, 
  any 
  further 
  than 
  w^hen 
  the 
  waters 
  of 
  the 
  lake 
  occupied 
  that 
  

   level, 
  the 
  controlling 
  conditions, 
  wiiatever 
  they 
  may 
  have 
  been, 
  

   were 
  certainly 
  not 
  favorable 
  or 
  conducive 
  to 
  their 
  formation. 
  In 
  

   other 
  words, 
  the 
  explanation 
  proposed 
  is 
  conjectural. 
  

  

  The 
  deltas 
  are 
  variable 
  in 
  size, 
  but 
  their 
  mode 
  of 
  formation 
  was 
  

   the 
  same, 
  as 
  can 
  be 
  seen 
  revealed 
  in 
  their 
  structure. 
  That 
  they 
  are 
  

   true 
  deltas 
  does 
  not 
  admit 
  of 
  reasonable 
  doubt. 
  Their 
  places 
  of 
  

   location, 
  relation 
  to 
  the 
  streams, 
  mode 
  of 
  formation 
  and 
  structure 
  

  

  