﻿7& 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  and 
  most 
  wonderful 
  animal 
  of 
  all, 
  did 
  not 
  appear 
  until 
  the 
  last 
  

   (Quaternary) 
  period 
  of 
  earth 
  history. 
  Birds 
  developed 
  to 
  much 
  

   like 
  their 
  present 
  forms. 
  Reptiles 
  diminished 
  both 
  in 
  size 
  and 
  

   number 
  of 
  species 
  in 
  a 
  remarkable 
  way, 
  while 
  fishes 
  took 
  on 
  a 
  

   decidedly 
  modern 
  aspect. 
  The 
  invertebrates 
  of 
  the 
  Tertiary 
  were 
  

   not 
  strikingly 
  different 
  from 
  those 
  of 
  the 
  present 
  and 
  by 
  the 
  close 
  

   of 
  the 
  period 
  they 
  were 
  so 
  modern 
  that 
  from 
  75 
  to 
  90 
  per 
  cent 
  of 
  

   them 
  were 
  even 
  the 
  same 
  species 
  as 
  those 
  now 
  living. 
  

  

  We 
  learned 
  that, 
  in 
  the 
  late 
  Mesozoic, 
  true 
  flowering 
  plants 
  had 
  

   been 
  developed 
  in 
  abundance, 
  and 
  during 
  the 
  Tertiary 
  these 
  and 
  

   all 
  other 
  plants 
  reached 
  a 
  development 
  which 
  in 
  no 
  essential 
  way 
  

   was 
  different 
  from 
  that 
  of 
  the 
  present. 
  

  

  The 
  records 
  of 
  Tertiary 
  life 
  are 
  but 
  scantily 
  represented 
  in 
  New 
  

   York 
  because 
  of 
  the 
  small 
  extent 
  of 
  exposed 
  Tertiary 
  rocks. 
  In 
  

   the 
  deposits 
  of 
  the 
  Atlantic 
  Coastal 
  plain, 
  however, 
  abundant 
  

   fossils 
  are 
  found. 
  

  

  Development 
  of 
  relief 
  features. 
  The 
  uplift 
  of 
  the 
  great 
  Cretacic 
  

   peneplain 
  was 
  an 
  event 
  of 
  prime 
  importance 
  for 
  New 
  York 
  because 
  

   it 
  literally 
  furnishes 
  us 
  with 
  the 
  beginning 
  of 
  the 
  history 
  of 
  most 
  

   of 
  the 
  existing 
  relief 
  features 
  of 
  the 
  State. 
  Hence 
  we 
  assert 
  with 
  

   emphasis 
  that 
  all 
  the 
  principal 
  topographic 
  features 
  of 
  the 
  State 
  as 
  

   we 
  see 
  them 
  today 
  date 
  from 
  the 
  uplift 
  of 
  the 
  Cretacic 
  peneplain 
  

   because 
  they 
  have 
  been 
  produced 
  by 
  the 
  dissection 
  of 
  that 
  upraised 
  

   surface. 
  This 
  dissection 
  was 
  largely 
  the 
  work 
  of 
  erosion, 
  though 
  

   in 
  the 
  eastern 
  Adirondack 
  region 
  faulting 
  has 
  produced 
  notable 
  

   effects. 
  All 
  the 
  great 
  valleys 
  such 
  as 
  the 
  Champlain, 
  St 
  Lawrence, 
  

   Black 
  river, 
  Mohawk, 
  and 
  Hudson 
  have 
  been 
  produced 
  since 
  the 
  

   uplift 
  of 
  the 
  peneplain. 
  It 
  should 
  also 
  be 
  stated 
  that 
  the 
  Great 
  

   Lakes, 
  as 
  well 
  as 
  the 
  numerous 
  lakes, 
  gorges, 
  and 
  waterfalls 
  for 
  

   which 
  New 
  York 
  is 
  noted, 
  were 
  absent 
  as 
  geographic 
  features 
  at 
  

   the 
  opening 
  of 
  the 
  Cenozoic. 
  

  

  As 
  previously 
  stated, 
  the 
  streams 
  of 
  New 
  York 
  which 
  flowed 
  

   upon 
  the 
  peneplain 
  surface 
  sluggishly 
  meandered 
  over 
  deep 
  alluvial 
  

   or 
  flood-plain 
  deposits, 
  and 
  their 
  courses 
  were 
  little 
  if 
  any 
  

   determined 
  by 
  the 
  character 
  of 
  the 
  underlying 
  rocks 
  because 
  hard 
  

   and 
  soft 
  rocks 
  alike 
  were 
  worn 
  down 
  to 
  a 
  general 
  level. 
  The 
  

   uplift 
  of 
  the 
  peneplain, 
  however, 
  greatly 
  revived 
  the 
  activity 
  of 
  

   the 
  streams 
  so 
  that 
  they 
  became 
  very 
  effective 
  agents 
  of 
  erosion 
  ; 
  

   they 
  first 
  cut 
  channels 
  through 
  the 
  alluvial 
  deposits 
  and 
  then 
  into 
  

   the 
  underlying 
  bedrock. 
  Thus 
  these 
  large 
  original 
  streams 
  had 
  

   their 
  courses 
  determined 
  in 
  the 
  overlying 
  deposits, 
  and 
  when 
  the 
  

   underlying 
  rocks 
  were 
  reached 
  the 
  same 
  courses 
  had 
  to 
  be 
  pursued 
  

  

  