﻿CLAYS 
  OF 
  NEW 
  YOKK 
  596 
  

  

  yellowish 
  brown 
  sand, 
  yellowish 
  brown 
  clay 
  and 
  stiff 
  blue 
  clay, 
  

   the 
  latter 
  being 
  rather 
  calcareous. 
  The 
  upper 
  clay 
  is 
  somewhat 
  

   silicious, 
  and 
  its 
  coloring 
  is 
  due 
  to 
  the 
  weathering 
  of 
  the 
  lower 
  

   layer. 
  This 
  formation 
  has 
  a 
  thickness 
  of 
  about 
  15 
  feet, 
  but 
  some- 
  

   times, 
  as 
  at 
  Burlington, 
  it 
  reaches 
  a 
  thickness 
  of 
  100 
  feet. 
  Iso- 
  

   lated 
  boulders 
  are 
  occasionally 
  found 
  in 
  the 
  clays, 
  and 
  are 
  con- 
  

   sidered 
  by 
  Emmons 
  to 
  have 
  been 
  dropped 
  there 
  by 
  icebergs. 
  The 
  

   clays 
  are 
  usually 
  horizontally 
  stratified, 
  and 
  contortions 
  of 
  the 
  

   layers 
  are 
  extremely 
  rare. 
  i^Tumerous 
  fossils 
  have 
  been 
  found 
  in 
  

   the 
  overlying 
  sands, 
  among 
  them 
  being 
  Saxicava 
  rugosa 
  

   Lamarck 
  and 
  Tellina 
  groenlandica 
  Beck, 
  which 
  are 
  

   very 
  common 
  ; 
  Tritonium 
  anglicum, 
  Tritonium 
  

   fornicatum, 
  Mytilus 
  edulis 
  Linn., 
  Pecten 
  islan- 
  

   d 
  i 
  c 
  u 
  s 
  Chemnitz, 
  Mva 
  truncata 
  Linn. 
  , 
  M 
  . 
  a 
  r 
  e 
  n 
  a 
  r 
  i 
  a 
  

   Linn., 
  J^ucula 
  portlandica; 
  the 
  skeleton 
  of 
  a 
  whale 
  has 
  

   also 
  been 
  found 
  in 
  these 
  deposits.^ 
  

  

  Openings 
  have 
  been 
  made 
  in 
  them 
  for 
  the 
  purpose 
  of 
  obtaining 
  

   brick 
  clays 
  at 
  Plattsburg 
  and 
  a 
  few 
  other 
  localities, 
  but, 
  owing 
  to 
  

   the 
  lateness 
  of 
  the 
  season 
  when 
  I 
  visited 
  them, 
  information 
  was 
  

   hard 
  to 
  obtain. 
  

  

  hong 
  Island 
  clays 
  

  

  Long 
  Island 
  is 
  made 
  up 
  of 
  a 
  series 
  of 
  sands, 
  gravels 
  and 
  clays, 
  

   which 
  form 
  two 
  parallel 
  ranges 
  of 
  hills 
  in 
  the 
  northei-n 
  half 
  of 
  

   the 
  island, 
  while 
  the 
  southern 
  half 
  is 
  a 
  flat 
  plain. 
  The 
  most 
  

   southern 
  of 
  the 
  ranges 
  represents 
  the 
  hmit 
  of 
  the 
  drift. 
  ^ 
  

  

  The 
  clay 
  beds 
  are 
  exposed 
  along 
  the 
  north 
  shore 
  of 
  the 
  island 
  

   and 
  at 
  several 
  points 
  along 
  the 
  main 
  line 
  of 
  the 
  Long 
  Island 
  rail- 
  

   road. 
  In 
  describing 
  them 
  I 
  have 
  gone 
  east 
  along 
  the 
  north 
  shore 
  

   and 
  come 
  back 
  through 
  the 
  center 
  of 
  the 
  island. 
  

  

  In 
  a 
  paper 
  on 
  the 
  geology 
  of 
  Long 
  Island, 
  (previously 
  cited) 
  

  

  1 
  The 
  writer 
  has 
  found 
  one 
  species 
  of 
  diatom 
  belonging 
  to 
  the 
  genus 
  diatoma, 
  

   in 
  the 
  clay 
  from 
  Plattsburg. 
  

  

  2 
  For 
  a 
  detailed 
  account 
  of 
  the 
  topography 
  of 
  Long 
  Island 
  see 
  Mather, 
  

   Geol. 
  New 
  York, 
  1st 
  dist. 
  1843; 
  W. 
  Uphani, 
  A. 
  J. 
  8., 
  Ill, 
  18; 
  F. 
  J. 
  H. 
  Mer- 
  

   rill, 
  "Geology 
  of 
  Long 
  Island," 
  Ann. 
  N. 
  Y. 
  acad. 
  sci. 
  1884. 
  

  

  