﻿FIFTH 
  REPORT 
  OF 
  THE 
  DIRECTOR 
  I908 
  I9 
  

  

  the 
  central 
  and 
  eastern 
  parts 
  of 
  the 
  State 
  two 
  sheets 
  of 
  till 
  are 
  

   indicated, 
  one 
  superimposed 
  on 
  the 
  other. 
  The 
  indications 
  are 
  that 
  

   the 
  later 
  ice 
  invasion 
  was 
  very 
  weak. 
  

  

  The 
  southward 
  overflow 
  of 
  the 
  ice-impounded 
  waters 
  held 
  in 
  

   the 
  Black 
  river 
  valley 
  built 
  high 
  and 
  broad 
  deltas 
  in 
  the 
  vicinity 
  of 
  

   Trenton 
  and 
  Trenton 
  Falls, 
  and 
  later 
  north 
  of 
  Rome. 
  During 
  the 
  

   time 
  of 
  this 
  overflow 
  and 
  earlier, 
  glacial 
  waters 
  were 
  also 
  held 
  in 
  the 
  

   Mohawk 
  valley 
  much 
  above 
  the 
  Iroquois 
  level, 
  and 
  on 
  the 
  west 
  and 
  

   south 
  flanks 
  of 
  the 
  Adirondacks 
  above 
  the 
  Black 
  river 
  waters. 
  The 
  

   existence 
  of 
  these 
  high 
  waters 
  has 
  been 
  found 
  to 
  be 
  due 
  to 
  the 
  ice 
  

   blockade 
  of 
  the 
  IMohawk 
  valley. 
  As 
  the 
  Labradoran 
  ice 
  sheet 
  

   waned 
  and 
  the 
  Adirondack 
  rock 
  surface 
  w^as 
  exposed 
  the 
  On- 
  

   tarian 
  ice 
  lobe 
  pushed 
  eastward 
  nito 
  the 
  upper 
  Mohawk 
  valley 
  

   while 
  the 
  Hudson 
  river 
  lobe 
  pushed 
  westward 
  up 
  the 
  same 
  valley. 
  

   At 
  an 
  early 
  stage 
  of 
  this 
  opposing 
  flow 
  through 
  the 
  Mohawk 
  valley 
  

   the 
  westward 
  flow 
  of 
  the 
  Hudson 
  lobe 
  prevailed 
  and 
  excellent 
  

   drumlins 
  were 
  formed 
  by 
  westward 
  moving 
  ice, 
  as 
  far 
  as 
  Cedarville,. 
  

   12 
  miles 
  southeast 
  of 
  Utica. 
  Professor 
  Brigham 
  has 
  reported 
  the 
  

   presence 
  of 
  west 
  pointing 
  drumlins 
  in 
  the 
  Johnstown 
  district. 
  

  

  It 
  is 
  quite 
  possible 
  that 
  the 
  earliest 
  waters 
  which 
  gathered 
  in 
  the 
  

   valleys 
  of 
  the 
  Adirondacks 
  found 
  escape 
  across 
  the 
  Mohawk 
  glacier 
  

   to 
  Susquehanna 
  drainage. 
  Certainly 
  there 
  came 
  a 
  time 
  when 
  an 
  

   open 
  lake 
  was 
  held 
  in 
  the 
  Mohawk 
  valley 
  between 
  the 
  two 
  opposing 
  

   ice 
  lobes. 
  The 
  earliest 
  overflow 
  of 
  this 
  Mohawk 
  glacial 
  lake 
  seems 
  

   to 
  have 
  been 
  across 
  the 
  col 
  6 
  miles 
  east 
  of 
  Richfield 
  Springs 
  and 
  

   at 
  the 
  head 
  of 
  the 
  Otsego 
  valley, 
  wath 
  present 
  elevation 
  of 
  1360 
  

   feet. 
  The 
  many 
  broad 
  delta 
  plains 
  at 
  1440 
  feet 
  on 
  the 
  south 
  flank 
  

   of 
  the 
  Adirondacks 
  correlates 
  with 
  this 
  outlet 
  when 
  allowance 
  is 
  

   made 
  for 
  the 
  postglacial 
  deformation 
  of 
  the 
  land. 
  A 
  lower 
  escape 
  

   of 
  the 
  Mohawk 
  lake 
  was 
  found 
  at 
  Cedarville 
  at 
  the 
  head 
  of 
  the 
  

   Unadilla 
  valley, 
  with 
  altitude 
  1220 
  feet. 
  This 
  pass 
  correlates 
  with 
  

   the 
  conspicuous 
  sand 
  plains 
  at 
  1300 
  feet 
  altitude. 
  Possibly 
  a 
  still 
  

   lower 
  escape 
  was 
  found 
  at 
  Bouckville 
  to 
  the 
  Chenango 
  valley 
  at 
  

   ii6o 
  feet. 
  But 
  soon 
  the 
  overflow 
  w^as 
  shifted 
  to 
  the 
  eastward 
  by 
  

   the 
  backing 
  away 
  of 
  the 
  ice 
  front 
  from 
  the 
  face 
  of 
  the 
  Helderberg 
  

   scarp, 
  10 
  miles 
  southwest 
  of 
  Schenectady. 
  

  

  The 
  Schoharie 
  valley 
  had 
  held 
  glacial 
  waters 
  (as 
  shown 
  by 
  

   Professor 
  Brigham 
  in 
  my 
  last 
  report) 
  with 
  earliest 
  outlet 
  by 
  one 
  or 
  

   more 
  of 
  the 
  three 
  passes 
  at 
  the 
  head 
  of 
  the 
  basin, 
  at 
  1920 
  feet. 
  

   Later 
  the 
  Schoharie 
  waters 
  blended 
  with 
  the 
  Mohawk 
  waters 
  with 
  

   overflow 
  by 
  the 
  outlets 
  leading 
  to 
  Susquehanna 
  drainage, 
  as 
  noted 
  

   above. 
  The 
  pass 
  at 
  1500 
  feet 
  to 
  the 
  Schenevus 
  valley 
  never 
  carried 
  

   any 
  flood. 
  The 
  pass 
  south 
  of 
  Middleburg 
  to 
  the 
  Catskill 
  creek. 
  

  

  