﻿252 
  R. 
  D. 
  Salisbury 
  — 
  Age 
  of 
  the 
  Orange 
  Sa?ids. 
  

  

  Art. 
  XXIV. 
  — 
  A 
  .Further 
  Note 
  on 
  the 
  Age 
  of 
  the 
  Orange 
  

   Sands 
  ; 
  by 
  R. 
  D. 
  Salisbury. 
  

  

  In 
  a 
  recent 
  number 
  of 
  this 
  Journal, 
  President 
  Chamberlin 
  

   and 
  the 
  writer 
  set 
  forth 
  what 
  seemed 
  to 
  us 
  sufficient 
  reasons 
  

   for 
  believing 
  the 
  whole 
  of 
  the 
  Orange 
  Sand 
  series 
  of 
  sands 
  

   and 
  gravels 
  to 
  be 
  of 
  Pre-pleistocene 
  age. 
  The 
  arguments 
  

   there 
  adduced 
  we 
  still 
  believe 
  to 
  be 
  sufficient 
  to 
  warrant 
  the 
  

   conclusions 
  drawn 
  from 
  them. 
  

  

  Since 
  that 
  article 
  appeared, 
  some 
  new 
  facts 
  have 
  come 
  to 
  

   our 
  knowledge 
  which 
  afford 
  new 
  and 
  more 
  direct 
  proof 
  of 
  the 
  

   correctness 
  of 
  the 
  position 
  then 
  taken. 
  Until 
  this 
  season's 
  

   work 
  in 
  the 
  field 
  began, 
  it 
  was 
  not 
  known 
  to 
  us 
  that 
  the 
  

   Orange 
  Sand 
  gravels 
  reached 
  so 
  far 
  north 
  as 
  the 
  southern 
  bor- 
  

   der 
  of 
  the 
  glacial 
  drift. 
  They 
  had 
  been 
  searched 
  for 
  along 
  the 
  

   southern 
  border 
  of 
  the 
  drift 
  north 
  of 
  the 
  area 
  where 
  they 
  are 
  

   best 
  known, 
  in 
  the 
  hope 
  that 
  they 
  might 
  be 
  found 
  beneath 
  the 
  

   glacial 
  deposits, 
  but 
  this 
  search 
  had 
  been 
  fruitless, 
  so 
  far 
  as 
  the 
  

   particular 
  question 
  at 
  issue 
  is 
  concerned. 
  

  

  During 
  the 
  early 
  part 
  of 
  this 
  season's 
  field-work, 
  the 
  writer 
  

   spent 
  some 
  time 
  in 
  the 
  region 
  between 
  the 
  Mississippi 
  and 
  

   Illinois 
  rivers 
  above 
  the 
  point 
  of 
  their 
  junction. 
  In 
  this 
  

   region, 
  in 
  the 
  counties 
  of 
  Calhoun, 
  Pike, 
  Adams 
  and 
  Hancock, 
  

   the 
  Orange 
  Sand 
  gravels 
  were 
  found 
  to 
  obtain 
  a 
  considerable 
  

   development. 
  These 
  counties 
  are 
  well 
  north 
  of 
  the 
  southern 
  

   limit 
  of 
  the 
  glacial 
  drift, 
  and 
  the 
  gravel 
  is 
  uniformly 
  found 
  to 
  

   occupy 
  a 
  position 
  beneath 
  it. 
  Among 
  other 
  places, 
  this 
  rela- 
  

   tionship 
  is 
  well 
  shown 
  near 
  Bloomfield, 
  Adams 
  county, 
  where 
  

   till 
  may 
  be 
  seen 
  resting 
  directly 
  on 
  the 
  brown 
  flint 
  gravels. 
  

   Here, 
  as 
  at 
  several 
  other 
  localities, 
  the 
  gravel 
  is 
  cemented 
  by 
  

   . 
  iron 
  oxide 
  into 
  a 
  firm 
  conglomerate, 
  though 
  at 
  other 
  points 
  but 
  

   a 
  few 
  rods 
  away, 
  the 
  gravel 
  is 
  but 
  partially 
  or 
  not 
  at 
  all 
  

   cemented. 
  It 
  will 
  be 
  remembered 
  that 
  this 
  habit 
  of 
  being 
  

   firmly 
  cemented 
  at 
  one 
  point, 
  and 
  nearly 
  or 
  altogether 
  free 
  

   from 
  cement 
  at 
  another, 
  is 
  one 
  of 
  the 
  prominent 
  characteristics 
  

   of 
  the 
  gravel 
  farther 
  south. 
  

  

  But 
  the 
  Pre-pleistocene 
  (presumably 
  Tertiary) 
  series 
  of 
  the 
  

   counties 
  named 
  is 
  not 
  limited 
  to 
  the 
  brown 
  flint 
  or 
  " 
  Orange 
  " 
  

   gravels. 
  Accompanying 
  these, 
  there 
  are 
  very 
  considerable 
  

   beds 
  of 
  sand, 
  essentially 
  like 
  those 
  accompanying 
  the 
  corre- 
  

   sponding 
  gravels 
  to 
  the 
  south. 
  These 
  are 
  best 
  exposed, 
  so 
  far 
  

   as 
  the 
  writer's 
  knowledge 
  goes, 
  a 
  short 
  distance 
  south 
  of 
  Lib- 
  

   erty, 
  Adams 
  county, 
  but 
  they 
  have 
  a 
  considerable 
  development 
  

   in 
  various 
  parts 
  of 
  this 
  county. 
  At 
  the 
  above 
  locality, 
  till 
  may 
  

   be 
  seen 
  resting 
  on 
  the 
  sand. 
  

  

  