﻿pleistocf:ne 
  geology 
  of 
  Nassau 
  go. 
  and 
  borough 
  of 
  queens 
  64^ 
  

  

  halt 
  is 
  rather 
  to 
  be 
  compared 
  with 
  those 
  nearly 
  stagnant 
  ice 
  fronts 
  

   which 
  are 
  marked 
  over 
  southeastern 
  Massachusetts 
  and 
  in 
  the 
  Nar- 
  

   ragansett 
  bay 
  region 
  by 
  similar 
  sand 
  plains 
  formed 
  in 
  the 
  retreat 
  

   of 
  the 
  ice 
  from 
  the 
  long 
  maintained 
  frontage 
  on 
  and 
  against 
  the 
  

   Cape 
  Cod 
  moraine, 
  a 
  stage 
  everywhere 
  on 
  these 
  islands 
  marked 
  by 
  

   well 
  developed 
  outwash 
  plains. 
  

  

  Glacial 
  streams. 
  The 
  course 
  of 
  glacial 
  streams 
  escaping 
  from 
  

   the 
  ice 
  front 
  and 
  extending 
  over 
  the 
  frontal 
  plain 
  on 
  the 
  south 
  side 
  

   of 
  the 
  island 
  is 
  plainly 
  indicated 
  by 
  the 
  creases 
  extending 
  from 
  the 
  

   moraines 
  near 
  the 
  head 
  of 
  the 
  north 
  shore 
  harbors 
  and 
  from 
  other 
  

   passes 
  in 
  the 
  main 
  moraine. 
  The 
  principal 
  of 
  these 
  streams 
  seem 
  

   to 
  have 
  followed 
  tlie 
  course 
  of 
  the 
  harbors, 
  if 
  we 
  may 
  judge 
  from 
  

   the 
  cross-section 
  of 
  the 
  erosion 
  channel 
  or 
  interruption 
  of 
  the 
  

   moraine 
  where 
  they 
  crossed 
  it. 
  Tlie 
  most 
  instructive 
  of 
  these 
  chan- 
  

   nels 
  across 
  the 
  moraine 
  is 
  at 
  Roslyn 
  ; 
  there 
  is 
  another 
  at 
  Manhasset, 
  

   and 
  still 
  another 
  less 
  marked 
  at 
  the 
  southern 
  end 
  of 
  Greatneck 
  bay. 
  

  

  In 
  each 
  of 
  these 
  cases 
  the 
  larger 
  valleys 
  quite 
  up 
  to 
  the 
  pass 
  

   in 
  the 
  moraine 
  appear 
  to 
  have 
  been 
  occupied 
  by 
  ice 
  at 
  the 
  time 
  

   tlie 
  ice 
  sheet 
  began 
  to 
  melt 
  away. 
  The 
  thalweg 
  north 
  of 
  the 
  pass 
  

   or 
  divide 
  rises 
  steeply, 
  usually 
  from 
  tlie 
  bay 
  side, 
  invariably 
  much 
  

   steeper 
  than 
  the 
  gradient 
  of 
  those 
  valleys 
  which, 
  elsewhere 
  on 
  the 
  

   surface 
  of 
  the 
  23lains 
  north 
  of 
  the 
  moraine, 
  have 
  been 
  interpreted 
  as 
  

   older 
  than 
  the 
  last 
  ice 
  advance. 
  The 
  pass 
  in 
  the 
  moraine 
  north 
  of 
  

   Creedmoor 
  at 
  the 
  southern 
  end 
  of 
  Little 
  !Neck 
  bay 
  is 
  about 
  150 
  feet 
  

   above 
  sealevel 
  ; 
  that 
  of 
  Manhasset 
  bay 
  is 
  about 
  170 
  feet. 
  The 
  Ros- 
  

   lyn 
  channel 
  is 
  at 
  about 
  130 
  feet. 
  There 
  is 
  thus 
  no 
  accordance 
  of 
  

   level 
  in 
  these 
  outlets. 
  

  

  Other 
  passes 
  across 
  the 
  main 
  or 
  inner 
  moraine 
  occur 
  west 
  of 
  Ros- 
  

   lyn 
  at 
  about 
  230 
  feet, 
  and 
  east 
  of 
  Harbor 
  hill 
  at 
  about 
  90 
  feet. 
  

   Southeast 
  of 
  Brook 
  ville 
  there 
  is 
  a 
  pass 
  at 
  about 
  230 
  feet, 
  and 
  south 
  

   of 
  East 
  Korwich 
  another 
  at 
  about 
  210 
  feet. 
  All 
  of 
  these 
  appear 
  to 
  

   be 
  more 
  or 
  less 
  in 
  line 
  with 
  certain 
  valleys 
  north 
  of 
  the 
  moraine, 
  

   and 
  all 
  of 
  them 
  lead 
  out 
  south 
  of 
  the 
  moraine 
  into 
  creases 
  which 
  

   descend 
  to 
  the 
  sea. 
  

  

  The 
  broad 
  depression 
  passing 
  by 
  Locust 
  Grove 
  toward 
  East 
  N'or- 
  

   wich 
  is 
  not 
  wholly 
  erosional 
  in 
  origin. 
  Just 
  north 
  of 
  the 
  road 
  at 
  

   Locust 
  Grove 
  the 
  bottom 
  descends 
  into 
  a 
  large 
  elliptic 
  pit 
  suggesting 
  

  

  