﻿PLEISTOCENE 
  GEOLOGY 
  OF 
  NASSAU 
  CO. 
  AND 
  BOKOUGH 
  OF 
  QUEENS 
  645 
  

  

  Yellow 
  and 
  yellowish 
  gravels 
  occur 
  in 
  some 
  of 
  the 
  railway 
  cuts, 
  but 
  

   it 
  has 
  not 
  been 
  possible 
  in 
  the 
  present 
  survey 
  satisfactorily 
  to 
  delinnt 
  

   such 
  older 
  deposits, 
  excejDt 
  in 
  one 
  case, 
  that 
  of 
  the 
  Far 
  Rockaway 
  

   ridge. 
  This 
  peculiar 
  deposit 
  is 
  described 
  on 
  p. 
  651. 
  

  

  The 
  materials 
  exhibit 
  at 
  surface 
  a 
  gradual 
  diminution 
  in 
  coarse- 
  

   ness 
  from 
  coarse 
  gravel 
  near 
  the 
  inner 
  moraine 
  to 
  iine 
  sands 
  at 
  the 
  

   outer 
  limits 
  of 
  the 
  plain. 
  A 
  shallow 
  excavation 
  in 
  the 
  county 
  

   building 
  site 
  at 
  Mineola 
  exhibited 
  alternating 
  layers 
  of 
  coarse, 
  nut- 
  

   sized 
  gravel 
  and 
  fine 
  sandy 
  gravel 
  with 
  feebly 
  developed 
  crossbeds 
  

   at 
  intervals. 
  The 
  j)ebbles 
  were 
  mostly 
  wdiite 
  quartz 
  and 
  gneiss, 
  

   this 
  latter 
  often 
  decayed. 
  More 
  rarely 
  were 
  seen 
  small 
  pebbles 
  of 
  

   ironstone 
  and 
  a 
  ferruginous 
  conglomerate 
  of 
  white 
  quartz 
  pebbles. 
  

   Pebbles 
  as 
  large 
  as 
  3 
  inches 
  in 
  diameter 
  were 
  extremely 
  rare. 
  

  

  A 
  rather 
  anomalous 
  element 
  for 
  the 
  upper 
  part 
  of 
  the 
  section 
  of 
  

   the 
  plain 
  is 
  the 
  brick 
  clay 
  found 
  at 
  East 
  Williston. 
  While 
  clays 
  

   would 
  normally 
  develop 
  about 
  the 
  margin 
  of 
  a 
  plain 
  of 
  this 
  char- 
  

   acter 
  in 
  the 
  sea, 
  to 
  be 
  subsequently 
  overlain 
  by 
  the 
  outward 
  growth 
  

   of 
  the 
  thickening 
  plain, 
  such 
  clays 
  would 
  hardly 
  be 
  formed 
  with 
  a 
  

   surface 
  so 
  nearly 
  that 
  of 
  the 
  completed 
  gravel 
  plain 
  ; 
  and 
  it 
  is 
  prob- 
  

   able 
  that 
  these 
  are 
  either 
  an 
  older 
  degraded 
  deposit 
  or 
  owe 
  their 
  

   position 
  to 
  the 
  deformation 
  and 
  uplift 
  of 
  the 
  basement 
  on 
  which 
  the 
  

   deposits 
  and 
  topography 
  of 
  the 
  last 
  extraglacial 
  streams 
  have 
  been 
  

   imposed. 
  The 
  section, 
  which 
  is 
  exposed 
  in 
  a 
  somewhat 
  depressed, 
  

   troughlike 
  area, 
  is 
  as 
  follows 
  : 
  

  

  SECTION 
  OF 
  CLAYS 
  AT 
  EAST 
  WILLISTON 
  

  

  Feet 
  

  

  Soils... 
  1.5 
  

  

  Sand, 
  gravelly, 
  with 
  quartz 
  and 
  granitic 
  pebbles, 
  locally 
  red-^ 
  

  

  dened 
  , 
  

  

  Clays, 
  sandy, 
  with 
  quartz 
  pebbles 
  

  

  Clay, 
  sandy 
  in 
  yellow 
  band 
  

  

  Clay, 
  blue, 
  finely 
  laminate, 
  rarely 
  with 
  quartz 
  pebbles, 
  

  

  exposed 
  3 
  

  

  The 
  section 
  is 
  apparently 
  conformable 
  throughout. 
  Crosby, 
  if 
  I 
  

   understand 
  him 
  rightly, 
  would 
  refer 
  these 
  clays 
  to 
  the 
  Tertiary. 
  

  

  The 
  manner 
  in 
  which 
  the 
  water 
  percolating 
  through 
  the 
  sand 
  

   plain 
  north 
  of 
  and 
  above 
  the 
  60 
  foot 
  contour 
  in 
  the 
  Hempstead 
  

  

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  8 
  

  

  