﻿PLEISTOCENE 
  GEOLOGY 
  OF 
  NASSAU 
  CO. 
  AND 
  BOROUGH 
  OF 
  QUEENS 
  64:9 
  

  

  angle 
  rarely 
  as 
  steep 
  as 
  that 
  of 
  repose 
  of 
  sliding 
  materials 
  on 
  an 
  

   ancient 
  cliff 
  whose 
  base 
  has 
  been 
  abandoned 
  bj 
  the 
  sea. 
  One 
  such 
  

   steep 
  place 
  a 
  few 
  yards 
  in 
  length 
  occurs 
  between 
  Jamaica 
  and 
  

   IIolHs. 
  

  

  Along 
  the 
  base 
  of 
  the 
  slope 
  at 
  the 
  inner 
  edge 
  of 
  the 
  plain, 
  

   if 
  wave 
  action 
  had 
  determined 
  the 
  lineality 
  of 
  the 
  morainal 
  front 
  

   and 
  secondarily 
  its 
  slope, 
  there 
  is 
  a 
  lack 
  of 
  the 
  critical 
  evidence 
  

   which 
  one 
  would 
  expect 
  to 
  find 
  at 
  the 
  place. 
  The 
  generally 
  

   unstratified 
  character 
  of 
  the 
  deposit 
  forming 
  the 
  morainal 
  front 
  

   offers 
  little 
  evidence 
  as 
  to 
  whether 
  it 
  has 
  been 
  cut 
  back 
  by 
  wave 
  

   action 
  or 
  not, 
  but 
  on 
  the 
  west 
  side 
  of 
  Prospect 
  park 
  in 
  Brooklyn 
  

   decisive 
  evidence 
  on 
  this 
  point 
  is 
  found. 
  

  

  West 
  of 
  Prospect 
  park 
  the 
  morainal 
  front 
  maintains 
  its 
  lineal 
  

   course 
  toward 
  New 
  York 
  narrows, 
  but 
  with 
  a 
  rather 
  bulging 
  

   frontal 
  slope 
  composed 
  of 
  stratified 
  gravels. 
  As 
  seen 
  in 
  pits 
  open 
  

   in 
  the 
  season 
  of 
  1900, 
  these 
  stratified 
  gravels 
  rise 
  up 
  steeply 
  from 
  

   the 
  northern 
  margin 
  of 
  the 
  frontal 
  plain, 
  then 
  bend 
  downward 
  into 
  

   a 
  large 
  kettle-hole 
  in 
  tlie 
  deposit, 
  a 
  depression 
  marking 
  the 
  site 
  of 
  a 
  

   mass 
  of 
  ice. 
  The 
  attitude 
  of 
  the 
  beds 
  suggests 
  frontal 
  shoving 
  on 
  

   the 
  part 
  of 
  the 
  ice 
  sheet 
  as 
  well 
  as 
  irregular 
  deposition 
  ; 
  but 
  the 
  

   significant 
  feature 
  at 
  this 
  locality 
  is 
  tlie 
  apparent 
  absence 
  of 
  any- 
  

   thing 
  like 
  a 
  cut 
  bench 
  or 
  cliff 
  in 
  the 
  bulging 
  front 
  of 
  the 
  deposit. 
  

  

  The 
  structure 
  of 
  the 
  sand 
  plain 
  is 
  exposed 
  in 
  occasional 
  pits. 
  

   The 
  beds 
  are 
  prevailingly 
  cross-bedded, 
  showing 
  frequent 
  reversals 
  

   in 
  direction 
  of 
  the 
  transportation 
  of 
  the 
  sediments. 
  Such 
  cross- 
  

   bedded 
  layers 
  occur 
  in 
  glacial 
  gravels 
  where 
  there 
  is 
  no 
  reason 
  for 
  

   supposing 
  the 
  sea 
  to 
  have 
  acted 
  on 
  them. 
  

  

  On 
  the 
  east, 
  on 
  the 
  Oyster 
  Bay 
  sheet, 
  the 
  inner 
  margin 
  ' 
  of 
  this 
  

   frontal 
  plain 
  rises 
  above 
  the 
  100 
  foot 
  contour 
  level 
  ; 
  in 
  this 
  region 
  

   it 
  sinks 
  gradually 
  below 
  it, 
  till 
  north 
  of 
  the 
  Jamaica 
  bay 
  depression, 
  

   where 
  the 
  plain 
  has 
  a 
  width 
  not 
  exceeding 
  IJ 
  miles 
  above 
  sealevel, 
  

   its 
  hight 
  next 
  the 
  moraine 
  is 
  only 
  60 
  feet 
  ; 
  westward 
  it 
  rises 
  slightly 
  

   again. 
  For 
  a 
  portion 
  of 
  its 
  length, 
  therefore, 
  this 
  line 
  accords 
  in 
  

   elevation 
  with 
  the 
  80 
  foot 
  level 
  of 
  the 
  water 
  body 
  in 
  which 
  the 
  

   Port 
  Washington 
  delta 
  was 
  built. 
  If 
  throughout 
  the 
  line 
  accorded 
  

   with 
  the 
  Port 
  Washington 
  level, 
  it 
  would 
  favor 
  the 
  existence 
  at 
  

   that 
  stage 
  of 
  a 
  body 
  of 
  water 
  in 
  front 
  of 
  as 
  well 
  as 
  in 
  the 
  rear 
  of 
  

  

  