﻿PLEISTOCENE 
  GEOLOGY 
  OF 
  NASSAU 
  CO. 
  AND 
  BOROUGH 
  OF 
  QUEENS 
  64:7 
  

  

  Washington 
  ; 
  hence 
  the 
  ice-laid 
  and 
  the 
  water-laid 
  drift 
  of 
  this 
  epi- 
  

   sode 
  are 
  here 
  assembled 
  under 
  the 
  name 
  of 
  the 
  Port 
  Wasliington 
  

   stage 
  of 
  ice 
  retreat. 
  

  

  Whether 
  some 
  of 
  the 
  deposits 
  lying 
  south 
  of 
  this 
  line 
  and 
  yet 
  

   north 
  of 
  the 
  moraine, 
  as 
  in 
  the 
  plain 
  north 
  of 
  Greenvale 
  station, 
  

   may 
  not 
  constitute 
  an 
  intermediate 
  series 
  of 
  deposits 
  can 
  only 
  be 
  

   determined 
  by 
  more 
  evidence 
  than 
  the 
  topography 
  of 
  the 
  deposits 
  

   ^lone 
  affords. 
  

  

  From 
  the 
  village 
  of 
  Port 
  Washington 
  northwestward 
  there 
  over- 
  

   looks 
  the 
  harbor 
  a 
  thick 
  plain 
  of 
  sand 
  with 
  a 
  lobate 
  margin. 
  These 
  

   lobes 
  point 
  inward 
  from 
  the 
  east 
  and 
  the 
  north 
  and 
  have 
  their 
  sum- 
  

   mit 
  line 
  traced 
  by 
  the 
  80 
  foot 
  contour 
  line. 
  The 
  plain 
  of 
  sand 
  is 
  

   free 
  from 
  boulders, 
  and 
  its 
  structure, 
  as 
  shown 
  in 
  numerous 
  deep 
  

   sand 
  pits, 
  consists 
  of 
  beds 
  dipping 
  everj^where 
  southward 
  toward 
  

   the 
  shore 
  at 
  angles 
  of 
  about 
  20°. 
  All 
  about 
  the 
  iceward 
  edge 
  of 
  

   the 
  sand 
  plain 
  are 
  boulder-strewn 
  fields, 
  which 
  on 
  the 
  north 
  and 
  

   west 
  have 
  a 
  decidedly 
  morainic 
  topography 
  below 
  the 
  100 
  foot 
  con- 
  

   tour 
  line. 
  From 
  near 
  Plum 
  point 
  around 
  the 
  coast 
  of 
  the 
  sound 
  to 
  

   Mott 
  point 
  this 
  topography 
  is 
  very 
  distinct, 
  forming 
  a 
  rough 
  slope 
  

   to 
  the 
  sea 
  rather 
  than 
  a 
  ridge 
  ; 
  but 
  the 
  morainal 
  deposits, 
  as 
  shown 
  

   at 
  Barker 
  point, 
  are 
  a 
  mere 
  veneer 
  over 
  older 
  glacial 
  beds. 
  

  

  The 
  topography 
  thus 
  defined 
  marks 
  the 
  overlap 
  of 
  the 
  ice 
  sheet 
  at 
  

   this 
  stage 
  on 
  Manhasset 
  neck, 
  and 
  the 
  sand 
  plain 
  is 
  a 
  delta 
  formed 
  

   in 
  a 
  body 
  of 
  water 
  whose 
  surface 
  was 
  approximately 
  at 
  the 
  level 
  of 
  

   the 
  summit 
  line 
  of 
  the 
  lobate 
  margin 
  of 
  the 
  deposit. 
  

  

  It 
  follows 
  from 
  this 
  conclusion 
  that, 
  if 
  other 
  sand 
  plains 
  at 
  this 
  

   level 
  occur 
  to 
  the 
  east 
  and 
  west 
  on 
  the 
  north 
  side 
  of 
  the 
  moraine 
  

   within 
  approximately 
  the 
  same 
  distance 
  of 
  retreat 
  from 
  the 
  main 
  

   moraine, 
  the 
  probable 
  position 
  of 
  the 
  ice 
  front 
  at 
  this 
  later 
  stage 
  

   may 
  be 
  traced 
  by 
  drawing 
  a 
  line 
  along 
  the 
  northern 
  margin 
  of 
  these 
  

   deltas. 
  

  

  Another 
  such 
  deposit 
  less 
  clearly 
  developed 
  occurs 
  at 
  Great 
  IN'eck 
  

   village 
  at 
  approximately 
  the 
  same 
  hight 
  ; 
  and, 
  as 
  the 
  line 
  between 
  

   the 
  inner 
  margin 
  of 
  the 
  sand 
  plain 
  and 
  the 
  ice 
  edge 
  on 
  the 
  western 
  

   part 
  of 
  Manhasset 
  neck 
  turns 
  in 
  this 
  direction, 
  it 
  appears 
  legitimate 
  

   to 
  associate 
  the 
  two 
  deposits 
  in 
  the 
  manner 
  indicated. 
  The 
  line 
  

   thus 
  drawn 
  suffices 
  to 
  show 
  that 
  the 
  front 
  of 
  the 
  ice 
  sheet 
  was 
  at 
  

  

  