﻿GEOLOGIC 
  FORMATIONS 
  OF 
  NEW 
  YOKK 
  175 
  

  

  The 
  Tertiary 
  of 
  our 
  Atlantic 
  slope 
  consists 
  chiefly 
  of 
  sands 
  and 
  

   clays, 
  which 
  in 
  the 
  southern 
  states 
  are 
  well 
  developed. 
  A 
  much 
  

   larger 
  development 
  occurs 
  west 
  of 
  the 
  Mississippi 
  river 
  on 
  the 
  

   sites 
  of 
  extinct 
  Tertiary 
  lakes. 
  Marine 
  Tertiary 
  is 
  also 
  found 
  on 
  

   the 
  Pacific 
  coast. 
  

  

  In 
  New 
  York 
  state 
  the 
  Tertiary 
  is 
  not 
  accurately 
  identified 
  and 
  

   is 
  indivisible, 
  but 
  is 
  probably 
  represented 
  by 
  sands 
  and 
  gravel 
  

   on 
  Staten 
  Island 
  and 
  Long 
  Island. 
  There 
  is 
  comparatively 
  little 
  

   marine 
  Tertiary 
  in 
  North 
  America, 
  as 
  the 
  northern 
  part 
  of 
  the 
  

   continent 
  was 
  out 
  of 
  water 
  at 
  that 
  time. 
  The 
  Tertiary 
  beds 
  w^est 
  

   of 
  the 
  Mississippi 
  are 
  chiefly 
  fresh 
  water 
  deposits 
  formed 
  in 
  lake 
  

   basins. 
  The 
  Tertiary 
  was 
  a 
  period 
  of 
  mountain 
  making. 
  In 
  

   southern 
  Europe 
  the 
  great 
  chains 
  of 
  mountains 
  known 
  locally 
  

   as 
  the 
  Pyrenees, 
  Alps, 
  Apennines 
  and 
  Carpathians, 
  consist 
  to 
  a 
  

   large 
  extent 
  of 
  Tertiary 
  rocks. 
  This 
  is 
  also 
  true 
  of 
  the 
  Himalaya 
  

   mountains 
  of 
  India. 
  It 
  is 
  known 
  that 
  extensive 
  disturbances 
  

   in 
  our 
  Appalachian 
  system 
  occurred 
  during 
  the 
  Tertiary. 
  

  

  Life 
  of 
  the 
  Tertiary 
  period 
  

  

  Birds 
  and 
  mammals 
  succeeded 
  the 
  reptiles 
  of 
  the 
  cretaceous. 
  

   Of 
  the 
  mammals 
  all 
  the 
  orders 
  now 
  existing 
  w^ere 
  represented. 
  

   Reptiles 
  were 
  not 
  more 
  numerous 
  than 
  at 
  present 
  and 
  were 
  simi- 
  

   lar 
  to 
  existing 
  genera. 
  Fishes 
  were 
  very 
  abundant. 
  Insects 
  

   were 
  many 
  and 
  varied. 
  Mollusks 
  were 
  abundant; 
  oysters 
  oc- 
  

   curred 
  in 
  great 
  variety 
  and 
  of 
  enormous 
  size. 
  Corals 
  were 
  not 
  

   j)lentiful. 
  Land 
  plants 
  were 
  very 
  abundant 
  and 
  very 
  similar 
  to 
  

   those 
  of 
  the 
  present 
  day; 
  the 
  cypress 
  grew 
  in 
  the 
  Arctic 
  regions. 
  

  

  QUATERNARY 
  SYSTEM 
  

  

  At 
  the 
  Close 
  of 
  the 
  Tertiary 
  a 
  cold 
  temperate 
  climate 
  reigned 
  

   in 
  the 
  United 
  States 
  and 
  a 
  great 
  ice 
  age 
  began, 
  during 
  which 
  the 
  

   northern 
  part 
  of 
  our 
  continent 
  was 
  covered 
  with 
  a 
  sheet 
  of 
  ice 
  

   many 
  hundred 
  feet 
  thick. 
  The 
  chief 
  evidences 
  of 
  this 
  are 
  the 
  

   inscriptions 
  of 
  the 
  continental 
  glaciers 
  on 
  the 
  rocks 
  in 
  the 
  shape 
  

  

  