﻿226 
  Brigham 
  — 
  Drift 
  Bowlders 
  in 
  Central 
  New 
  York. 
  

  

  of 
  Hamilton, 
  limestones 
  are 
  rare 
  above 
  the 
  kame 
  and 
  terrace 
  

   limit, 
  for 
  which 
  100 
  feet 
  is 
  an 
  average 
  figure. 
  

  

  The 
  writer 
  has 
  not 
  found 
  a 
  fully 
  satisfactory 
  interpretation 
  

   for 
  the 
  distribution 
  of 
  the 
  limestones. 
  The 
  case 
  may 
  be 
  stated 
  

   as 
  follows 
  : 
  from 
  8 
  to 
  12 
  feet 
  of 
  sandstone 
  are 
  intercalated 
  in 
  

   the 
  midst 
  of 
  200 
  or 
  more 
  feet 
  of 
  limestones 
  at 
  Oriskany 
  Falls. 
  

   The 
  whole 
  mass 
  was 
  attacked 
  by 
  the 
  glacier. 
  The 
  amount 
  of 
  

   limestone 
  left 
  on 
  the 
  hills 
  southward 
  bears 
  no 
  comparison 
  to 
  

   the 
  amount 
  of 
  sandstone. 
  The 
  limestone 
  is 
  practically 
  absent 
  

   from 
  the 
  hill 
  summits 
  beyond 
  six 
  miles. 
  The 
  Oriskany 
  con- 
  

   tinues 
  in 
  good 
  force 
  for 
  over 
  20 
  miles. 
  That, 
  the 
  Lower 
  Hel- 
  

   derberg 
  continues 
  far 
  south 
  in 
  the 
  valley 
  train, 
  might 
  be 
  

   expected, 
  from 
  prolonged 
  erosion 
  in 
  the 
  valley 
  bottom 
  at 
  Oris- 
  

   kany 
  Falls, 
  during 
  the 
  presence 
  of 
  the 
  ice 
  front 
  there, 
  after 
  

   work 
  upon 
  the 
  higher 
  sandstones 
  had 
  become 
  ineffective. 
  But 
  

   how 
  shall 
  we 
  get 
  the 
  limestone 
  deposited 
  in 
  kames, 
  with 
  some 
  

   striations 
  still 
  preserved, 
  at 
  Oxford, 
  40 
  miles 
  south, 
  without 
  

   carrying 
  the 
  fragments 
  of 
  the 
  same 
  terrane 
  to 
  the 
  hills 
  above 
  ? 
  

   We 
  might 
  suppose 
  a 
  valley 
  tongue 
  to 
  account 
  for 
  the 
  kames 
  

   and 
  the 
  absence 
  from 
  the 
  hills, 
  but 
  the 
  distance 
  is 
  too 
  great, 
  

   with 
  the 
  slight 
  descent, 
  to 
  admit 
  of 
  this 
  view. 
  Owing 
  to 
  the 
  

   solubility 
  of 
  the 
  limestones 
  we 
  may 
  believe 
  them 
  less 
  capable 
  

   of 
  distant 
  carriage 
  by 
  glacial 
  action, 
  the 
  pebbles 
  of 
  the 
  valley 
  

   being 
  hastened 
  forward 
  by 
  sub-glacial 
  water 
  currents. 
  But 
  we 
  

   have 
  records 
  of 
  limestone 
  carriage 
  for 
  at 
  least 
  60 
  miles.* 
  Pro- 
  

   fessor 
  Shaler 
  notes 
  the 
  disappearance 
  of 
  crystalline 
  limestones 
  

   within 
  five 
  or 
  six 
  miles, 
  f 
  But 
  here 
  again 
  Emmons 
  records 
  the 
  

   finding 
  of 
  many 
  bowlders 
  of 
  "Primary" 
  limestone 
  south 
  of 
  

   Rome,:): 
  'New 
  York, 
  and 
  one 
  two 
  feet 
  in 
  diameter 
  is 
  reported 
  

   from 
  Clinton, 
  New 
  York. 
  These 
  latter 
  fragments 
  have 
  with 
  

   little 
  doubt 
  traveled 
  as 
  much 
  as 
  60 
  miles. 
  

  

  We 
  may 
  perhaps 
  find 
  relief 
  in 
  the 
  history 
  of 
  the 
  gathering 
  

   of 
  the 
  materials 
  by 
  the 
  ice. 
  The 
  Corniferous 
  overlaid 
  by 
  the 
  

   perishable 
  Marcellus 
  shale 
  and 
  breaking 
  up 
  easily 
  owing 
  to 
  its 
  

   large 
  quota 
  of 
  flints 
  and 
  the 
  solubility 
  of 
  the 
  lime, 
  may 
  have 
  

   receded 
  along 
  the 
  lines 
  of 
  its 
  ancient 
  outcrop, 
  leaving 
  consider- 
  

   able 
  areas 
  of 
  sandstone 
  exposed. 
  A 
  short 
  and 
  vigorous 
  ice 
  

   movement 
  might 
  pluck 
  and 
  carry 
  off 
  extensive 
  masses 
  of 
  the 
  

   sandstone, 
  before 
  action 
  became 
  highly 
  effective 
  upon 
  the 
  lime- 
  

   stone 
  ledges 
  in 
  retreat 
  above, 
  or 
  those 
  protected 
  below. 
  We 
  

   may 
  thus 
  suppose 
  the 
  Oriskany 
  to 
  be 
  well 
  started 
  on 
  its 
  jour- 
  

   ney 
  before 
  the 
  migration 
  of 
  the 
  limestones 
  was 
  fairly 
  begun. 
  

  

  * 
  Chamberlin 
  and 
  Salisbury, 
  Driftless 
  Area 
  of 
  the 
  Upper 
  Mississippi 
  Valley, 
  6th 
  

   Ann. 
  Rep. 
  U. 
  S. 
  G. 
  S., 
  p. 
  267 
  ; 
  also, 
  A. 
  P. 
  Low, 
  Glacial 
  Geology 
  of 
  Labrador 
  and 
  

   Quebec, 
  Bull. 
  G. 
  S. 
  A., 
  vol. 
  iv, 
  pp. 
  419-421. 
  

  

  f 
  Bowlder 
  Train 
  from 
  Iron 
  Hill, 
  Bull. 
  Mus. 
  Comp. 
  Zool., 
  vol. 
  xvi, 
  No. 
  11, 
  p. 
  

   206. 
  

  

  % 
  Agriculture 
  of 
  N. 
  Y., 
  vol. 
  i, 
  p 
  260. 
  

  

  