﻿628 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  of 
  the 
  area 
  of 
  the 
  Oyster 
  Bay 
  quadrangle 
  at 
  this 
  time. 
  The 
  thin- 
  

   ness 
  of 
  the 
  bed, 
  and 
  the 
  identity 
  of 
  the 
  sediments 
  which 
  underlie 
  and 
  

   succeed 
  it, 
  go 
  far 
  to 
  show 
  that 
  this 
  boulder 
  clay 
  making 
  was 
  but 
  an 
  

   episode 
  in 
  the 
  formation 
  of 
  the 
  gravels 
  and 
  sands 
  in 
  this 
  field. 
  

  

  The 
  outcrop 
  of 
  the 
  boulder 
  clay 
  bed 
  on 
  the 
  bluffs 
  gives 
  rise 
  to 
  

   boulders 
  which 
  have 
  slidden 
  down 
  the 
  slope. 
  A 
  section 
  transverse 
  

   to 
  the 
  face 
  of 
  the 
  bluff 
  in 
  one 
  of 
  the 
  pits 
  showed 
  an 
  ancient 
  talus 
  of 
  

   boulder 
  clay 
  extending 
  down 
  to 
  the 
  road. 
  ^N^ot 
  only 
  the 
  texture 
  

   and 
  structure 
  of 
  the 
  sands 
  and 
  gravels, 
  but 
  also 
  the 
  appearance 
  of 
  

   the 
  boulder 
  clay 
  bed 
  in 
  these 
  pits 
  indicates 
  that 
  these 
  deposits 
  

   extended 
  eastward 
  across 
  what 
  is 
  now 
  the 
  bay 
  to 
  the 
  like 
  deposits 
  on 
  

   the 
  opposite 
  bluff. 
  Nowhere 
  do 
  the 
  deposits 
  show 
  that 
  increasing 
  

   coarseness 
  toward 
  their 
  exposed 
  edges 
  which 
  is 
  the 
  characteristic 
  

   mark 
  of 
  the 
  heads 
  of 
  glacial 
  sand 
  plains 
  and 
  those 
  bodies 
  of 
  glacial 
  

   sands 
  and 
  gravels 
  which 
  have 
  accumulated 
  about 
  the 
  edge 
  of 
  a 
  gla- 
  

   cier 
  or 
  its 
  outlying 
  stagnant 
  masses. 
  The 
  bays 
  are 
  clearly 
  valleys 
  of 
  

   erosion 
  cutting 
  through 
  both 
  the 
  Pleistocene 
  and 
  locally 
  the 
  pre- 
  

   Pleistocene 
  clays 
  and 
  sands 
  alike. 
  

  

  A 
  bed 
  of 
  till, 
  presumably 
  an 
  extension 
  of 
  that 
  above 
  described, 
  

   occurs 
  on 
  the 
  east 
  shore 
  of 
  Hempstead 
  bay 
  in 
  Glen 
  Cove 
  about 
  60 
  

   feet 
  above 
  sealevel, 
  in 
  the 
  following 
  incompletely 
  exposed 
  section. 
  

  

  PLEISTOCENE 
  SECTION 
  IN 
  GLEN 
  COVE, 
  FROM 
  TOP 
  

  

  Gravel 
  and 
  fine 
  sand 
  3 
  ft 
  

  

  Till, 
  with 
  small 
  angular 
  boulders 
  5 
  

  

  Gravel, 
  clayey 
  1 
  6 
  in. 
  

  

  Gravel, 
  sandy 
  3 
  

  

  Sand, 
  base 
  not 
  seen 
  3 
  

  

  20 
  feet 
  distant 
  the 
  till 
  passes 
  into 
  stratified 
  gravel 
  and 
  sand. 
  The 
  

   rapid 
  transition 
  of 
  the 
  till 
  into 
  stratified 
  drift 
  at 
  this 
  locality 
  explains 
  

   the 
  absence 
  of 
  the 
  bed 
  in 
  many 
  sections. 
  It 
  was 
  ^^robably 
  locally 
  

   deposited. 
  

  

  . 
  A 
  similar 
  till 
  bed 
  distinctly 
  less 
  bouldery 
  but 
  equally 
  amorphous, 
  

   is 
  exposed 
  in 
  the 
  bluff 
  at 
  Barker 
  point, 
  from 
  which, 
  first 
  appearing 
  

   at 
  about 
  20 
  feet 
  above 
  the 
  sealevel, 
  it 
  sinks, 
  on 
  the 
  western 
  face 
  of 
  

   this 
  headland, 
  southward, 
  being 
  involved 
  in 
  the 
  dislocations 
  of 
  the 
  

   north 
  coast 
  of 
  the 
  island 
  (fig. 
  2). 
  

  

  