﻿PLEISTOCENE 
  GEOLOGY 
  OF 
  NASSAU 
  CO. 
  AND 
  BOROIJGJI 
  OF 
  QUEENS 
  619 
  

  

  and 
  the 
  northern 
  ridge 
  rude 
  plains 
  of 
  coarse 
  gravels 
  rise 
  gently 
  

   toward 
  the 
  southern 
  face 
  of 
  the 
  latter. 
  Between 
  the 
  mounds 
  them- 
  

   selves, 
  these 
  plains 
  merge 
  southward 
  into 
  a 
  broad, 
  slightly 
  creased 
  

   plain, 
  which 
  sinks 
  to 
  the 
  level 
  of 
  the 
  marshes 
  and 
  the 
  sea 
  on 
  the 
  

   south 
  coast. 
  

  

  The 
  main 
  ridge 
  rises 
  very 
  frequently 
  to 
  a 
  hight 
  of 
  300 
  feet 
  above 
  

   sealevel, 
  and 
  from 
  100 
  to 
  150 
  feet 
  above 
  the 
  low 
  ground 
  at 
  its 
  base. 
  

   Where 
  most 
  distinct 
  in 
  its 
  topographic 
  features, 
  its 
  base 
  is 
  but 
  little 
  

   more 
  than 
  a 
  mile 
  wide. 
  Between 
  Syosset 
  on 
  the 
  south 
  and 
  East 
  

   Norwich 
  and 
  Brookville 
  on 
  the 
  north 
  side, 
  this 
  ridge 
  is 
  relatively 
  

   low 
  and 
  narrow. 
  Between 
  Jericho 
  and 
  Wheatley 
  three 
  or 
  four 
  

   well 
  marked 
  spurs 
  extend 
  for 
  one 
  or 
  two 
  miles 
  to 
  the 
  southward, 
  

   impinging 
  on 
  the 
  line 
  of 
  mounds 
  representing 
  the 
  continuation 
  of 
  

   the 
  southern 
  ridge 
  above 
  described. 
  West 
  of 
  this 
  broad 
  develop- 
  

   ment, 
  the 
  ridge 
  becomes 
  more 
  massive 
  and 
  elevated, 
  attaining 
  its 
  

   highest 
  point 
  in 
  Harbor 
  hill, 
  391 
  feet. 
  West 
  of 
  Roslyn, 
  it 
  gradually 
  

   falls 
  off 
  in 
  elevation, 
  and 
  from 
  Lake 
  Surprise 
  westward 
  becomes 
  a 
  

   low, 
  flat 
  ridge 
  with 
  a 
  steep 
  southerly 
  front 
  and 
  with 
  a 
  gentle 
  slope 
  

   northward. 
  The 
  broad 
  crest, 
  seldom 
  over 
  200 
  feet 
  above 
  the 
  sea, 
  is 
  

   cast 
  into 
  mounds 
  and 
  hollows, 
  or 
  knobs 
  and 
  basins, 
  some 
  of 
  the 
  latter 
  

   containing 
  small 
  tarns 
  or 
  lily 
  ponds, 
  a 
  feature 
  less 
  common 
  in 
  the 
  

   eastern 
  extension 
  of 
  the 
  ridge. 
  

  

  From 
  the 
  northern 
  base 
  of 
  the 
  ridge 
  there 
  extends 
  a 
  series 
  of 
  

   plains 
  or 
  terraces, 
  frequently 
  at 
  an 
  elevation 
  of 
  about 
  200 
  feet 
  near 
  

   the 
  ridge, 
  separated 
  by 
  the 
  wedge-shaped 
  harbors 
  of 
  the 
  north 
  shore. 
  

   These 
  surfaces 
  form 
  the 
  headlands 
  or 
  " 
  necks," 
  between 
  the 
  bays, 
  

   with 
  elevations 
  of 
  from 
  100 
  feet 
  to 
  nearly 
  200 
  feet. 
  The 
  surface 
  is 
  

   deeply 
  indented 
  by 
  valleys 
  mouthing 
  on 
  the 
  broader 
  indentations 
  of 
  

   the 
  coast 
  line 
  ; 
  and 
  in 
  the 
  vicinity 
  of 
  Oyster 
  Bay 
  harbor 
  the 
  land 
  is 
  

   reduced 
  to 
  a 
  few 
  islands, 
  now 
  tied 
  to 
  the 
  main 
  island 
  by 
  marine 
  

   beaches. 
  

  

  Between 
  these 
  rude 
  plains 
  on 
  the 
  north 
  and 
  the 
  broad 
  plain 
  on 
  

   the 
  south 
  the 
  deeper 
  reentrants 
  of 
  the 
  northern 
  coast 
  are 
  continued 
  

   by 
  narrow 
  depressions 
  across 
  the 
  main 
  ridge. 
  One 
  of 
  these 
  troughs 
  

   occurs 
  south 
  of 
  Manhasset, 
  another 
  at 
  Roslyn, 
  and 
  similar 
  passes 
  

   traverse 
  tlie 
  ridge 
  at 
  the 
  eastern 
  base 
  of 
  the 
  Harbor 
  hill 
  mass, 
  on 
  

   the 
  roa.d 
  from 
  Brookville 
  to 
  Locust 
  Grove, 
  and 
  eastward 
  along 
  the 
  

  

  