﻿GEOLOGIC 
  FOKMATIONS 
  OF 
  NEW 
  YORK 
  169 
  

  

  The 
  fossils 
  of 
  the 
  coal 
  measures 
  are 
  almost 
  entirely 
  vegetable. 
  

   In 
  the 
  slates 
  above 
  the 
  coal 
  seams, 
  most 
  perfect 
  and 
  beautiful 
  

   impressions 
  of 
  leaves 
  occur 
  in 
  profusion; 
  and 
  large 
  trunks 
  or 
  

   stems 
  are 
  found, 
  almost 
  always 
  compressed 
  to 
  a 
  thickness 
  of 
  only 
  

   an 
  inch 
  or 
  two, 
  though 
  two 
  feet 
  or 
  more 
  in 
  width. 
  The 
  greater 
  

   part 
  of 
  these 
  trees 
  seem 
  to 
  have 
  been 
  allied 
  to 
  the 
  tree-ferns 
  of 
  

   tropical 
  climates, 
  though 
  there 
  are 
  remains 
  of 
  coniferous 
  trees 
  

   and 
  several 
  other 
  vegetable 
  families. 
  The 
  character 
  of 
  this 
  fossil 
  

   vegetation 
  would 
  seem 
  to 
  indicate 
  that 
  at 
  the 
  time 
  it 
  grew, 
  a 
  far 
  

   warmer 
  climate 
  than 
  that 
  now 
  known 
  prevailed 
  over 
  the 
  tem- 
  

   perate 
  and 
  arctic 
  zones. 
  

  

  The 
  fact 
  that 
  coal 
  is 
  of 
  vegetable 
  origin, 
  seems 
  to 
  explain 
  why 
  

   the 
  lower 
  rocks 
  which 
  form 
  the 
  state 
  of 
  New 
  York 
  contain 
  no 
  

   coal. 
  Tliey 
  appear 
  to 
  have 
  been 
  formed 
  before 
  terrestrial 
  vegetation 
  

   flourished 
  to 
  an. 
  extent 
  sufficient 
  to 
  form 
  accumulations 
  of 
  this 
  suh- 
  

   stance. 
  

  

  The 
  first 
  relics 
  of 
  land 
  plants 
  are 
  found 
  in 
  the 
  Upper 
  Silurian; 
  

   above 
  this 
  they 
  become 
  more 
  numerous 
  and 
  in 
  the 
  Catskill 
  group 
  

   of 
  the 
  Devonian 
  are 
  quite 
  abundant, 
  forming 
  occasionally 
  minia- 
  

   ture 
  coal 
  seams 
  an 
  inch 
  thick. 
  

  

  In 
  the 
  Carboniferous 
  rocks 
  they 
  increase 
  suddenly 
  to 
  an 
  enor- 
  

   mous 
  quantity, 
  and 
  in 
  later 
  formations 
  are 
  found 
  in 
  considerable, 
  

   but 
  generally 
  in 
  less 
  abundance. 
  Coal 
  is 
  also 
  found 
  in 
  newer 
  

   rocks, 
  such 
  as 
  the 
  Jurassic, 
  Cretaceous 
  and 
  Tertiary. 
  The 
  coal 
  

   or 
  lignite 
  beds 
  of 
  the 
  central 
  part 
  of 
  the 
  continent 
  near 
  the 
  Rocky 
  

   mountains, 
  belong 
  to 
  the 
  Cretaceous 
  and 
  Tertiary 
  rocks. 
  The 
  

   coal 
  of 
  Vancouver 
  island 
  on 
  the 
  Pacific 
  coast 
  is 
  Cretaceous. 
  The 
  

   coal 
  beds 
  near 
  Richmond, 
  Virginia, 
  are 
  of 
  Triassic 
  age. 
  The 
  con- 
  

   clusions 
  to 
  be 
  drawn 
  from 
  our 
  present 
  knowledge 
  are 
  that 
  good 
  

   coal 
  is 
  found 
  above 
  the 
  Carboniferous 
  system, 
  but 
  never 
  below 
  it. 
  

  

  Permian 
  

  

  This 
  formation 
  which 
  is 
  well 
  developed 
  in 
  Europe, 
  taking 
  its 
  

  

  name 
  from 
  the 
  Province 
  of 
  Perm, 
  in 
  Russia, 
  is 
  not 
  known 
  to 
  exist 
  

  

  in 
  New 
  York 
  state. 
  It 
  occurs 
  in 
  Texas 
  and 
  its 
  vicinity. 
  It 
  has 
  

  

  been 
  suggested 
  that 
  some 
  of 
  the 
  uppermost 
  deposits 
  commonly 
  

  

  