﻿Brigham 
  — 
  Drift 
  Bowlders 
  in 
  Central 
  New 
  York. 
  225 
  

  

  faces 
  only 
  upon 
  relatively 
  flat-topped 
  masses, 
  where 
  water 
  and 
  

   frosts 
  would 
  act 
  effectively, 
  and 
  along 
  fossil 
  zones, 
  where 
  a 
  

   retreat 
  of 
  three 
  to 
  six 
  inches 
  from 
  the 
  general 
  surface 
  is 
  not 
  

   uncommon. 
  On 
  the 
  whole 
  'it 
  is 
  thought 
  that 
  the 
  surfaces 
  at 
  

   the 
  ledge 
  average 
  slightly 
  fresher 
  than 
  those 
  to 
  the 
  southward. 
  

   On 
  the 
  other 
  hand 
  the 
  impression 
  given 
  is, 
  that 
  all 
  the 
  Oriskany 
  

   masses 
  belong 
  to 
  the 
  same 
  general 
  movement, 
  and 
  that 
  move- 
  

   ment 
  a 
  kte 
  one. 
  No 
  buried 
  specimens 
  of 
  large 
  Oriskany 
  bowl- 
  

   ders 
  have 
  "been 
  found. 
  They 
  have 
  the 
  appearance 
  of 
  being 
  

   left 
  behind, 
  upon 
  the 
  surface 
  of 
  the 
  hills, 
  in 
  the 
  course 
  of 
  a 
  

   rapid 
  retreat. 
  They 
  are 
  not 
  often 
  associated 
  with 
  morainic 
  

   accumulations, 
  but 
  lie 
  upon 
  thinly 
  masked 
  linear 
  and 
  often 
  

   drumloidal 
  elevations. 
  The 
  relations 
  of 
  the 
  ledge, 
  the 
  bowl- 
  

   ders 
  associated 
  with 
  the 
  valley 
  kames 
  at 
  B, 
  and 
  the 
  bowlder 
  

   fields 
  of 
  the 
  succeeding 
  hills, 
  strongly 
  suggest 
  that 
  we 
  are 
  deal- 
  

   ing 
  with 
  one 
  piece 
  of 
  work 
  so 
  far 
  as 
  the 
  Oriskany 
  material 
  is 
  

   concerned. 
  

  

  But 
  it 
  does 
  not 
  seem 
  probable 
  that 
  the 
  carriage 
  and 
  letting 
  

   down 
  of 
  the 
  Oriskany 
  bowlders 
  can 
  belong 
  to 
  the 
  general 
  

   advance 
  to 
  the 
  southern 
  limit 
  of 
  glaciation 
  and 
  the 
  retreat 
  

   therefrom 
  ; 
  for 
  on 
  this 
  supposition 
  they 
  should 
  have 
  reached 
  

   to 
  Binghamton 
  and 
  beyond. 
  The 
  texture, 
  indeed, 
  is 
  not 
  so 
  

   firm 
  as 
  that 
  of 
  the 
  Oneidas, 
  but 
  the 
  comparatively 
  abrupt 
  man- 
  

   ner 
  in 
  which 
  they 
  terminate 
  renders 
  their 
  connection 
  with 
  a 
  

   long 
  continued 
  and 
  far 
  southward 
  movement 
  questionable. 
  It 
  

   is 
  suggested 
  as 
  a 
  matter 
  for 
  farther 
  inquiry, 
  whether 
  the 
  ter- 
  

   mination 
  of 
  some 
  such 
  vigorous 
  and 
  rapid 
  forward 
  movement 
  

   as 
  seems 
  indicated 
  by 
  these 
  bowlders, 
  may 
  not 
  be 
  marked 
  by 
  

   the 
  kames 
  and 
  other 
  valley 
  accumulations 
  between 
  Oxford 
  and 
  

   Greene, 
  just 
  southward 
  from 
  the 
  last 
  found 
  pieces 
  of 
  the 
  sand- 
  

   stone. 
  This 
  section 
  belongs 
  to 
  a 
  " 
  Collateral 
  belt 
  of 
  moraines 
  " 
  

   described 
  by 
  Chamberlin, 
  in 
  this 
  region.* 
  

  

  Corniferous 
  Limestones. 
  — 
  This 
  formation 
  overlies 
  the 
  Oris- 
  

   kany 
  sandstone 
  at 
  Oriskany 
  Falls, 
  and 
  has 
  a 
  thickness 
  of 
  at 
  

   least 
  50 
  feet. 
  For 
  three 
  or 
  four 
  miles 
  it 
  is 
  quite 
  freely 
  mixed 
  

   with 
  other 
  rocks 
  in 
  the 
  hillside 
  drift. 
  Northwest 
  of 
  Hamilton, 
  

   where 
  the 
  turn 
  of 
  the 
  valley 
  brings 
  the 
  Oriskany 
  drift 
  upon 
  its 
  

   western 
  wall, 
  Corniferous 
  bowlders 
  are 
  found 
  far 
  exceeding 
  

   those 
  seen 
  elsewhere. 
  One 
  slab 
  near 
  the 
  valley 
  bottom 
  meas- 
  

   ures 
  19x11^x3 
  feet. 
  Farther 
  up, 
  other 
  and 
  more 
  rounded 
  

   masses 
  were 
  seen, 
  one 
  of 
  which 
  measured 
  6x6x9 
  feet. 
  Near 
  

   Eaton 
  village 
  also 
  is 
  a 
  tract 
  where 
  limestones 
  exceed 
  all 
  other 
  

   materials 
  of 
  the 
  bowlder 
  drift. 
  This 
  illustrates 
  a 
  quite 
  general 
  

   fact 
  in 
  the 
  distribution 
  of 
  the 
  more 
  local 
  drift, 
  that 
  the 
  blocks 
  

   of 
  a 
  given 
  kind 
  are 
  often 
  found 
  in 
  groups, 
  dependent 
  upon 
  

   local 
  conditions 
  of 
  exposure, 
  plucking 
  and 
  transport. 
  South 
  

  

  * 
  Term. 
  Mor. 
  Sec. 
  Gl. 
  Exp 
  , 
  3d 
  Ann. 
  Rep. 
  U. 
  S. 
  G. 
  8., 
  p. 
  372. 
  

  

  