﻿Brigham 
  — 
  Drift 
  Bowlders 
  in 
  Central 
  New 
  York. 
  215 
  

  

  quartzite 
  knobs 
  of 
  Wisconsin. 
  * 
  The 
  pre-Paleozoic 
  rocks 
  

   referred 
  to 
  in 
  this 
  paper 
  are 
  for 
  convenience 
  classed 
  as 
  

   Archaean. 
  The 
  nearest 
  outcrops, 
  except 
  by 
  faulting 
  at 
  Little 
  

   Falls, 
  are 
  at 
  the 
  southwestern 
  base 
  of 
  the 
  Adirondacks, 
  30 
  

   miles 
  from 
  Utica. 
  The 
  Cambrian 
  is 
  represented 
  by 
  the 
  Pots- 
  

   dam 
  sandstone 
  of 
  St. 
  Lawrence, 
  Jefferson 
  and 
  Lewis 
  Coun- 
  

   ties. 
  The 
  Ordovician 
  consists 
  of 
  Calciferous, 
  Trenton, 
  Utica 
  

   and 
  Hudson 
  Kiver, 
  outcropping 
  in 
  a 
  nearly 
  N. 
  W. 
  by 
  

   S. 
  E. 
  direction, 
  only 
  the 
  Utica 
  and 
  Hudson 
  River 
  appearing 
  as 
  

   far 
  south 
  as 
  the 
  Mohawk 
  valley, 
  in 
  this 
  region. 
  The 
  Silu- 
  

   rian 
  beds, 
  Oneida-Medina, 
  Clinton, 
  Niagara, 
  Salina 
  and 
  Lower 
  

   Helderberg, 
  cross 
  our 
  field 
  in 
  nearly 
  east 
  and 
  west 
  bands, 
  and 
  

   as 
  a 
  whole 
  extend 
  south 
  to 
  Oriskany 
  Falls. 
  It 
  is 
  evident 
  from 
  

   the 
  sharp 
  descent 
  from 
  the 
  divide 
  to 
  the 
  Mohawk, 
  that 
  the 
  out- 
  

   crops 
  must 
  be 
  narrow 
  and 
  that 
  the 
  bottom 
  ice 
  was 
  pushed 
  up 
  

   across 
  their 
  bevelled 
  edges. 
  The 
  Devonian 
  column 
  begins 
  

   with 
  the 
  Oriskany 
  sandstone, 
  Corniferous 
  and 
  Marcellus 
  about 
  

   Oriskany 
  Falls 
  and 
  Waterville 
  and 
  passes 
  to 
  a 
  broad 
  band 
  of 
  

   Hamilton 
  extending 
  southward 
  to 
  Smyrna, 
  where 
  it 
  is 
  succeeded 
  

   by 
  the 
  Upper 
  Devonian 
  members, 
  continuing 
  to 
  Binghamton. 
  

   Of 
  the 
  above 
  masses, 
  the 
  Calciferous 
  and 
  Trenton 
  have 
  not 
  

   been 
  recognized 
  within 
  the 
  field 
  studied, 
  though 
  they 
  doubtless 
  

   exist 
  in 
  small 
  fragments. 
  The 
  older 
  and 
  more 
  distant 
  Pots- 
  

   dam 
  forms 
  a 
  quite 
  constant 
  element 
  in 
  our 
  drift, 
  being 
  com- 
  

   posed, 
  both 
  in 
  its 
  cement 
  and 
  constituent 
  grains, 
  of 
  nearly 
  pure 
  

   quartz. 
  But 
  without 
  microscopic 
  examination 
  it 
  is 
  in 
  danger 
  

   of 
  being 
  confused 
  with 
  certain 
  Medina 
  and 
  Clinton 
  fragments 
  

   which 
  resemble 
  it 
  in 
  color, 
  f 
  The 
  Utica, 
  Salina 
  and 
  Marcellus 
  

   are 
  too 
  soft 
  for 
  massive 
  transportation 
  beyond 
  short 
  distances. 
  

   The 
  sandstones 
  of 
  the 
  Hudson 
  River, 
  and 
  to 
  a 
  large 
  extent 
  of 
  

   the 
  Clinton, 
  have 
  not 
  afforded 
  ready 
  identification, 
  being 
  

   largely 
  without 
  fossils 
  and 
  weathering 
  to 
  a 
  non-committal 
  

   brown. 
  \ 
  The 
  Niagara 
  is 
  very 
  thin 
  in 
  Oneida 
  County, 
  though 
  

   a 
  certain 
  peculiar 
  structure 
  is 
  very 
  characteristic^ 
  and 
  four 
  or 
  

   five 
  pebbles 
  have 
  been 
  found 
  from 
  20 
  to 
  50 
  miles 
  from 
  its 
  out- 
  

   crop. 
  The 
  main 
  reliance 
  has 
  been 
  upon 
  the 
  Archaean, 
  Oneida, 
  

   Lower 
  Helderberg, 
  Oriskany 
  Sandstone 
  and 
  Corniferous. 
  A 
  

   separate 
  discussion 
  of 
  these 
  terranes 
  and 
  their 
  bowlders 
  will 
  fol- 
  

   low. 
  Sandstones 
  of 
  the 
  Hamilton 
  and 
  several 
  of 
  the 
  higher 
  

  

  * 
  Ira 
  M. 
  Buell, 
  Trans. 
  Wis. 
  Acad. 
  Sci., 
  ix, 
  pp. 
  255-274; 
  Cf. 
  T. 
  C. 
  Chamberlin, 
  

   Jour. 
  Geo!., 
  i. 
  pp. 
  255-267. 
  

  

  f 
  Since 
  writing 
  the 
  above, 
  Professor 
  C. 
  H. 
  §myth, 
  Jr. 
  has 
  kindly 
  subjected 
  to 
  

   microscopic 
  examination 
  a 
  representative 
  fragment 
  from 
  my 
  specimens, 
  finding 
  it 
  

   to 
  be 
  a 
  thoroughly 
  indurated 
  quartzite, 
  not 
  likely 
  to 
  be 
  matched 
  in 
  any 
  of 
  our 
  

   lower 
  Paleozoic 
  horizons 
  save 
  the 
  Potsdam. 
  

  

  \On 
  limitation 
  of 
  identification, 
  see, 
  The 
  Drift 
  — 
  its 
  Characteristics 
  and 
  Rela- 
  

   tionships. 
  R. 
  D. 
  Salisbury, 
  Jour. 
  G-eol., 
  vol. 
  ii, 
  Oct.-Nov., 
  1894, 
  p. 
  717. 
  

  

  § 
  Vanuxem, 
  Geol. 
  3d. 
  Dist. 
  N. 
  Y., 
  pp. 
  92, 
  93. 
  

  

  