﻿Diastrophism 
  in 
  Atlantic- 
  Arctic 
  Region. 
  21 
  

  

  part 
  of 
  Silurian 
  time, 
  probably 
  preceding 
  and 
  in 
  part 
  

   contemporaneous 
  with 
  the 
  folding 
  of 
  the 
  districts 
  now 
  

   bordering 
  the 
  Norwegian 
  Sea. 
  In 
  the 
  more 
  southern 
  

   American 
  region 
  we 
  have 
  an 
  especially 
  strong 
  rising 
  

   movement 
  of 
  the 
  corresponding 
  land-mass 
  in 
  younger 
  

   Devonian 
  time, 
  which 
  was 
  here 
  one 
  of 
  folding. 
  Here 
  is 
  

   indeed 
  a 
  similarity 
  that 
  may 
  have 
  a 
  wide 
  bearing 
  on 
  our 
  

   views 
  as 
  to 
  the 
  nature 
  of 
  diastrophism. 
  

  

  Most 
  American 
  geologists 
  believe 
  in 
  a 
  rather 
  high 
  

   degree 
  of 
  permanency 
  of 
  the 
  great 
  features 
  of 
  the 
  earth- 
  

   relief. 
  The 
  old 
  land 
  of 
  Appalachia 
  is 
  therefore 
  gen- 
  

   erally 
  thought 
  to 
  be 
  a 
  relatively 
  narrow 
  one, 
  and 
  the 
  

   geosyncline 
  to 
  be 
  an 
  unstable 
  belt 
  near 
  the 
  border 
  of 
  the 
  

   continent 
  — 
  near 
  the 
  deep 
  oceanic 
  basin. 
  This 
  view 
  is 
  

   thus 
  the 
  opposite 
  of 
  that 
  of 
  Haug, 
  who 
  holds 
  that 
  the 
  

   geosynclines 
  in 
  general 
  have 
  been 
  originally 
  bordered 
  by 
  

   two 
  continental 
  masses. 
  With 
  the 
  knowledge 
  that 
  may 
  

   be 
  gained 
  from 
  the 
  studies 
  of 
  the 
  region 
  considered 
  in 
  

   this 
  article, 
  the 
  view 
  as 
  to 
  the 
  northwest 
  European 
  geo- 
  

   syncline 
  must 
  be 
  that 
  it 
  is 
  bordered 
  on 
  one 
  side 
  by 
  a 
  

   stable 
  continental 
  element 
  (as 
  shown 
  on 
  Haug's 
  well- 
  

   known 
  structural 
  map 
  of 
  Europe), 
  on 
  the 
  other 
  by 
  a 
  

   large 
  area 
  of 
  the 
  crust 
  which 
  through 
  long 
  geologic 
  

   periods 
  had 
  the 
  tendency 
  to 
  rise. 
  Furthermore, 
  we 
  see 
  

   how 
  this 
  same 
  area, 
  like 
  the 
  eastern 
  part 
  of 
  Appalachia, 
  

   has 
  sunk 
  deeply, 
  and 
  at 
  the 
  present 
  time 
  very 
  consider- 
  

   able 
  oceanic 
  deeps 
  exist 
  in 
  it. 
  In 
  the 
  light 
  of 
  the 
  entire 
  

   geologic 
  history, 
  this 
  area, 
  if 
  given 
  a 
  designation, 
  might 
  

   be 
  called 
  the 
  element 
  of 
  greatest 
  vertical 
  movement. 
  

  

  It 
  certainly 
  will 
  be 
  hopeless 
  for 
  the 
  advocates 
  of 
  per- 
  

   manency 
  of 
  the 
  oceanic 
  basins 
  to 
  apply 
  the 
  theory 
  to 
  the 
  

   Norwegian 
  Sea. 
  In 
  places, 
  e. 
  g., 
  at 
  Spitzbergen, 
  the 
  

   shelf, 
  as 
  is 
  shown 
  in 
  Nansen's 
  map, 
  is 
  very 
  narrow, 
  and 
  

   great 
  depths 
  are 
  found 
  not 
  far 
  to 
  the 
  west 
  of 
  the 
  place 
  

   where 
  the 
  huge 
  continental 
  sandstones 
  of 
  Devonian 
  

   time 
  — 
  many 
  thousand 
  feet 
  in 
  thickness 
  — 
  are 
  still 
  to 
  be 
  

   seen. 
  Land 
  must 
  have 
  existed 
  where 
  there 
  is 
  now 
  deep 
  

   sea. 
  A 
  consequence 
  of 
  this 
  view 
  is 
  that 
  the 
  greater 
  

   density 
  of 
  the 
  sub-oceanic 
  crust 
  areas 
  must 
  be 
  regarded 
  

   as 
  due 
  to 
  secondary 
  processes 
  during 
  and 
  after 
  the 
  sub- 
  

   sidence. 
  

  

  Our 
  interpretation 
  of 
  the 
  nature 
  of 
  the 
  areas 
  lying 
  

   outside 
  the 
  geosynclines 
  naturally 
  influences 
  in 
  the 
  most 
  

   definite 
  way 
  our 
  view 
  as 
  to 
  the 
  nature 
  and 
  causes 
  of 
  the 
  

  

  