﻿224 
  Brigham 
  — 
  Drift 
  Bowlders 
  in 
  Central 
  New 
  York. 
  

  

  Falls. 
  This 
  would 
  give 
  them 
  an 
  average 
  elevation 
  of 
  250 
  feet 
  

   in 
  an 
  average 
  distance 
  of 
  4J 
  miles. 
  The 
  single 
  mass 
  before 
  

   noted 
  (E) 
  would 
  thus 
  have 
  been 
  raised 
  366 
  feet 
  in 
  3J 
  miles. 
  

   TJpham 
  notes 
  the 
  uplifting 
  of 
  Niagara 
  bowlders 
  to 
  a 
  height 
  of 
  

   100 
  to 
  200 
  feet 
  within 
  three 
  or 
  four 
  miles* 
  C. 
  H. 
  Hitchcock 
  

   reports 
  the 
  lifting 
  of 
  bowlders 
  4,000 
  feet 
  in 
  the 
  White 
  Moun- 
  

   tains 
  within 
  moderate 
  distances.^ 
  

  

  As 
  already 
  suggested, 
  the 
  east 
  and 
  west 
  extension 
  of 
  the 
  cen- 
  

   tral 
  New 
  York 
  terranes 
  vitiates 
  conclusions 
  as 
  to 
  lateral 
  distri- 
  

   bution, 
  or 
  " 
  fanning 
  out 
  " 
  such 
  as 
  has 
  been 
  described 
  by 
  Pro- 
  

   fessor 
  Shaler 
  in 
  Khode 
  Island 
  and 
  Massachusetts. 
  The 
  Oriskany 
  

   sandstone 
  is 
  to 
  a 
  considerable 
  extent 
  exceptional, 
  however. 
  In 
  

   the 
  passage 
  above 
  cited, 
  Yanuxem 
  alludes 
  to 
  local 
  differences 
  

   and 
  recognizes 
  the 
  Oriskany 
  drift 
  as 
  from 
  Oriskany 
  Falls. 
  For 
  

   the 
  only 
  outcrop 
  in 
  the 
  next 
  valley 
  to 
  the 
  eastward 
  he 
  notes 
  

   the 
  presence 
  of 
  a 
  distinctive 
  character. 
  At 
  Munnsville, 
  6 
  miles 
  

   W. 
  N. 
  W. 
  the 
  Oriskany 
  is 
  not 
  present, 
  the 
  two 
  limestones 
  

   being 
  continuous, 
  and 
  the 
  bowlders 
  are 
  nearly 
  absent 
  from 
  

   Munnsville 
  to 
  Pecksport. 
  If 
  the 
  Oriskany 
  exists 
  in 
  the 
  valley 
  

   at 
  all 
  it 
  is 
  a 
  thin 
  wedge 
  south 
  of 
  Pratts, 
  carried 
  by 
  the 
  dip 
  

   beneath 
  the 
  valley 
  filling. 
  At 
  Morrisville, 
  10 
  miles 
  W. 
  S. 
  W., 
  

   a 
  deep 
  boring 
  apparently 
  found 
  no 
  trace 
  of 
  Oriskany, 
  except 
  

   quartz 
  grains 
  in 
  the 
  limestone.:): 
  The 
  ledge 
  at 
  Oriskany 
  Falls 
  

   thins 
  4 
  to 
  5 
  feet 
  southward 
  in 
  three-quarters 
  of 
  a 
  mile. 
  The 
  

   indications 
  are 
  that 
  it 
  thinned 
  northward 
  also. 
  It 
  is 
  a 
  shore 
  

   formation, 
  which 
  we 
  should 
  expect 
  to 
  find 
  variable 
  within 
  

   short 
  distances. 
  We 
  probably 
  have 
  a 
  thin 
  lens 
  of 
  sediment, 
  

   whose 
  maximum 
  thickness 
  is 
  at 
  the 
  present 
  exposed 
  ledge, 
  and 
  

   the 
  southward 
  bowlders 
  are 
  very 
  surely 
  to 
  be 
  connected 
  with 
  

   it. 
  In 
  the 
  adjacent 
  valleys, 
  east 
  and 
  west, 
  the 
  Oriskany 
  bowl- 
  

   ders, 
  with 
  slight 
  exception, 
  do 
  not 
  occur, 
  or 
  are 
  found 
  so 
  far 
  

   southward 
  that 
  they 
  can 
  have 
  come 
  across 
  from 
  the 
  Oriskany 
  

   valley. 
  

  

  The 
  fragments 
  fan 
  out 
  to 
  a 
  width 
  of 
  six 
  miles 
  in 
  a 
  distance 
  

   of 
  eight 
  miles.§ 
  This 
  cannot, 
  however, 
  be 
  taken 
  as 
  a 
  measure 
  

   of 
  normal 
  dispersion 
  on 
  a 
  plane 
  surface, 
  for 
  the 
  diagonally 
  dis- 
  

   posed 
  valley 
  has 
  widened 
  the 
  train 
  rapidly 
  to 
  the 
  westward. 
  

  

  The 
  Oriskany 
  bowlders 
  were 
  observed 
  with 
  a 
  view 
  to 
  ascer- 
  

   taining 
  the 
  comparative 
  amount 
  of 
  disintegration 
  at 
  the 
  ledge 
  

   and 
  southward. 
  There 
  has 
  been 
  appreciable 
  loss 
  from 
  the 
  sur- 
  

  

  * 
  Eskers, 
  near 
  Rochester, 
  N. 
  Y., 
  Proc. 
  Roch. 
  Acad. 
  Sci., 
  vol. 
  ii, 
  p. 
  196, 
  and 
  

   Bull. 
  G. 
  S. 
  A., 
  vol. 
  v, 
  p. 
  76. 
  

  

  f 
  Bull. 
  G. 
  S. 
  A., 
  vol. 
  v, 
  p. 
  3*7. 
  See 
  also 
  this 
  Journal, 
  III, 
  vol. 
  xxviii, 
  p. 
  233; 
  

   Ibid., 
  vol. 
  v, 
  pp. 
  218, 
  219. 
  T. 
  C. 
  Chamberlin, 
  Jour. 
  GeoL, 
  vol. 
  i, 
  pp. 
  50-51. 
  

  

  % 
  C. 
  S. 
  Prosser, 
  " 
  The 
  Thickness 
  of 
  the 
  Devonian 
  and 
  Silurian 
  Rocks 
  of 
  Central 
  

   N. 
  Y.," 
  Bull. 
  G. 
  S. 
  A., 
  vol. 
  iv, 
  p. 
  96. 
  

  

  § 
  Cf. 
  "Bowlder 
  Train 
  from 
  Iron 
  Hill," 
  Bull. 
  Mus. 
  Comp. 
  Zool., 
  vol. 
  xvi, 
  No. 
  11, 
  

   pp. 
  196-202. 
  

  

  