﻿58 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  APPALACHIAN 
  MOUNTAIN 
  REVOLUTION 
  (CLOSE 
  OF 
  THE 
  

  

  PALEOZOIC) 
  

  

  The 
  Paleozoic 
  era 
  was 
  brought 
  to 
  a 
  close 
  by 
  one 
  of 
  the 
  most 
  pro- 
  

   found 
  physical 
  disturbances 
  in 
  the 
  history 
  of 
  North 
  America. 
  It 
  has 
  

   been 
  called 
  the 
  Appalachian 
  revolution 
  because 
  at 
  this 
  time 
  the 
  Ap- 
  

   palachian 
  mountain 
  range 
  was 
  born 
  out 
  of 
  the 
  sea 
  by 
  upheaval 
  and 
  

   folding 
  of 
  the 
  strata. 
  Because 
  of 
  the 
  direct 
  effect 
  of 
  this 
  great 
  

   upheaval 
  upon 
  the 
  history 
  of 
  New 
  York 
  State, 
  a 
  brief 
  description 
  

   is 
  given. 
  

  

  All 
  through 
  the 
  vast 
  time 
  (probably 
  ten 
  million 
  years) 
  of 
  the 
  

   Paleozoic 
  era, 
  a 
  great 
  land 
  mass 
  existed 
  along 
  what 
  is 
  now 
  the 
  

   eastern 
  coast 
  of 
  North 
  America. 
  This 
  land, 
  which 
  has 
  been 
  called 
  

   Appalachia, 
  had 
  its 
  western 
  boundary 
  approximately 
  along 
  the 
  

   present 
  coast 
  line, 
  while 
  it 
  must 
  have 
  extended 
  eastward 
  at 
  least 
  

   as 
  far 
  as 
  the 
  present 
  border 
  of 
  the 
  continental 
  shelf. 
  Concerning 
  the 
  

   altitude 
  and 
  character 
  of 
  the 
  topography 
  of 
  Appalachia 
  we 
  know 
  

   almost 
  nothing, 
  but 
  we 
  do 
  know 
  that 
  it 
  consisted 
  of 
  metamorphic 
  

   rock 
  of 
  Preeambric 
  age, 
  and 
  very 
  similar 
  to 
  that 
  of 
  the 
  Adirondacks. 
  

   The 
  tremendous 
  amount 
  of 
  derived 
  sediments 
  shows 
  that 
  Appala- 
  

   chia 
  was 
  high 
  enough 
  during 
  nearly 
  all 
  its 
  history 
  to 
  undergo 
  

   vigorous 
  erosion. 
  Although 
  oscillations 
  of 
  level 
  more 
  than 
  likely 
  

   affected 
  Appalachia, 
  and 
  its 
  western 
  shore 
  line 
  was 
  quite 
  certainly 
  

   somewhat 
  shifted 
  at 
  various 
  times, 
  nevertheless 
  it 
  persisted 
  as 
  a 
  

   great 
  land-mass 
  with 
  approximately 
  the 
  same 
  position 
  during 
  all 
  

   its 
  long 
  history. 
  Its 
  general 
  position 
  is 
  well 
  shown 
  on 
  the 
  map, 
  

   figure 
  16. 
  

  

  Barring 
  certain 
  minor 
  oscillations 
  of 
  level, 
  all 
  the 
  region 
  just 
  

   west 
  of 
  Appalachia 
  was 
  occupied 
  by 
  sea 
  water 
  during 
  the 
  whole 
  

   Paleozoic 
  era, 
  and 
  sediments 
  derived 
  from 
  the 
  erosion 
  of 
  Appala- 
  

   chia 
  were 
  laid 
  down 
  layer 
  upon 
  layer 
  upon 
  that 
  sea 
  bottom. 
  The 
  

   coarsest 
  and 
  greatest 
  thickness 
  of 
  sediments 
  was 
  deposited 
  nearest 
  

   the 
  land, 
  that 
  is 
  along 
  what 
  we 
  might 
  call 
  the 
  marginal 
  sea 
  bottom. 
  

   At 
  the 
  same 
  time 
  finer 
  sediments, 
  in 
  thinner 
  sheets, 
  were 
  being 
  

   deposited 
  all 
  over 
  the 
  Mississippi 
  valley 
  region. 
  By 
  actual 
  measure- 
  

   ment, 
  in 
  the 
  present 
  Appalachians, 
  we 
  know 
  that 
  the 
  maximum 
  

   thickness 
  of 
  these 
  sediments 
  was 
  at 
  least 
  25,000 
  feet. 
  These 
  are 
  

   all 
  of 
  comparatively 
  shallow 
  water 
  origin, 
  as 
  proved 
  by 
  the 
  coarse- 
  

   ness 
  of 
  sediment, 
  ripple 
  marks, 
  fossil 
  coral 
  reefs 
  etc., 
  and 
  so 
  we 
  

   are 
  forced 
  to 
  conclude 
  that 
  this 
  marginal 
  sea 
  bottom 
  gradually 
  sank 
  

   during 
  the 
  process 
  of 
  sedimentation, 
  thus 
  producing 
  what 
  is 
  called 
  

   a 
  great 
  geosynclinal 
  trough. 
  Perhaps 
  the 
  very 
  weight 
  of 
  accumu- 
  

  

  