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  NEW 
  TORK 
  STATE 
  MUSEUM 
  

  

  some 
  more 
  marked 
  differences 
  in 
  the 
  fossils 
  of 
  their 
  lower, 
  middle, 
  

   and 
  higher 
  portions, 
  on 
  account 
  of 
  which 
  they 
  have 
  been 
  separ- 
  

   ated 
  and 
  described 
  under 
  the 
  successive 
  divisions 
  of 
  the 
  Mar- 
  ^ 
  

   cellus, 
  Hamilton, 
  Genesee, 
  Portage, 
  Chemung 
  and 
  Catskill. 
  

  

  Hamilton 
  group 
  

  

  The 
  Hamilton 
  group, 
  named 
  from 
  its 
  exposure 
  at 
  Hamilton, 
  

   Madison 
  county, 
  consists 
  of 
  the 
  following 
  sub-divisions. 
  

  

  Group 
  Stage 
  

  

  r 
  Genesee 
  

   I 
  Tully 
  

   Tj 
  'u 
  J 
  ( 
  Moscow 
  shale 
  

  

  ' 
  Hamilton 
  ■< 
  Encrinal 
  limestone 
  

  

  ( 
  Ludlow 
  ville 
  shale 
  

   . 
  Marcellus 
  

  

  Marcellus 
  Shale 
  

  

  The 
  lowest 
  division, 
  resting 
  immediately 
  on 
  the 
  Upper 
  

   Helderberg 
  limestone, 
  was 
  named 
  from 
  the 
  village 
  of 
  Marcellus, 
  

   near 
  which 
  it 
  is 
  well 
  exposed. 
  It 
  is 
  a 
  mass 
  of 
  dark, 
  fissile, 
  short- 
  

   fractured 
  shale, 
  one 
  or 
  two 
  hundred 
  feet 
  in 
  thickness, 
  in 
  most 
  

   places 
  containing 
  layers 
  of 
  impure 
  limestone 
  and 
  rounded 
  con- 
  

   cretions 
  of 
  similar 
  material 
  in 
  its 
  lower 
  part. 
  

  

  At 
  the 
  village 
  of 
  Stafford 
  in 
  Genesee 
  county, 
  a 
  thin 
  limestone 
  

   is 
  well 
  exposed 
  about 
  40 
  feet 
  above 
  the 
  base 
  of 
  the 
  Marcellus. 
  

   It 
  has 
  been 
  called 
  by 
  Prof. 
  J. 
  M. 
  Clarke, 
  the 
  Stafford 
  Limestone, 
  

   and 
  extends 
  from 
  central 
  New 
  York 
  to 
  Lake 
  Erie. 
  

  

  In 
  Onondaga 
  county 
  the 
  Goniatite 
  limestone 
  replaces 
  the 
  Staf- 
  

   ford 
  limestone. 
  

  

  These 
  shales 
  closely 
  resemble 
  those 
  of 
  the 
  coal 
  formation 
  

   and 
  sometimes 
  contain 
  thin 
  seams 
  of 
  coaly 
  or 
  bituminous 
  

   matter, 
  which 
  have 
  misled 
  many 
  persons 
  to 
  spend 
  consider- 
  

   able 
  sums 
  in 
  digging 
  and 
  boring 
  in 
  them, 
  with 
  the 
  illfounded 
  

   expectation 
  of 
  finding 
  useful 
  layers 
  of 
  coal. 
  This 
  is 
  an 
  idle 
  hope, 
  

   for 
  they 
  lie 
  thousands 
  of 
  feet 
  below 
  the 
  Carboniferous 
  system, 
  

   beneath 
  which 
  no 
  valuable 
  coal 
  strata 
  have 
  ever 
  been 
  found. 
  

  

  