﻿12 
  0. 
  Holtedahl 
  — 
  Paleo 
  geography 
  and 
  

  

  author 
  is 
  considered 
  contemporaneous 
  with 
  the 
  Keyser 
  

   of 
  the 
  Appalachian 
  valley, 
  and 
  D 
  of 
  Lower 
  Helderberg 
  

   time. 
  Furthermore, 
  as 
  the 
  very 
  distinctly 
  folded 
  Cape 
  

   Bawson 
  beds 
  are, 
  according 
  to 
  Feilden's 
  observations, 
  

   unconformably 
  overlaid 
  by 
  later 
  Devonian 
  beds, 
  the 
  two 
  

   Danish 
  explorers 
  seem 
  justified 
  in 
  regarding 
  the 
  folding 
  

   in 
  the 
  far 
  north 
  of 
  Greenland 
  — 
  the 
  strike 
  is 
  here 
  south- 
  

   west-northeast 
  — 
  as 
  a 
  continuation 
  of 
  the 
  Caledonian 
  

   deformation 
  of 
  Spitzbergen 
  and 
  Europe. 
  As 
  the 
  folding 
  

   in 
  Spitzbergen 
  occurred 
  in 
  pre-Downtonian 
  time, 
  that 
  of 
  

   Greenland 
  must 
  be 
  regarded 
  as 
  a 
  delayed 
  Caledonian 
  

   movement. 
  

  

  I 
  will 
  not 
  describe 
  the 
  younger 
  Paleozoic 
  history 
  of 
  

   the 
  region 
  under 
  consideration 
  further 
  than 
  to 
  say 
  that 
  

   for 
  a 
  very 
  long 
  time 
  the 
  existence 
  of 
  the 
  large 
  North 
  

   Atlantic 
  continent 
  was 
  a 
  prominent 
  geographic 
  feature. 
  

   Even 
  though 
  this 
  continent 
  appears 
  to 
  have 
  been 
  a 
  rather 
  

   constant 
  geographic 
  element, 
  yet 
  it 
  was 
  certainly 
  far 
  

   from 
  being 
  a 
  quiet 
  and 
  stable 
  one. 
  This 
  unrest 
  is 
  seen 
  

   in 
  the 
  Devonian 
  sediments 
  in 
  the 
  districts 
  bordering 
  the 
  

   Norwegian 
  Sea, 
  for 
  the 
  Skandik 
  of 
  De 
  Geer 
  tell 
  of 
  enor- 
  

   mous 
  deposition 
  of 
  terrigenous 
  material. 
  This 
  immense 
  

   denudation 
  must 
  have 
  come 
  from 
  a 
  highland 
  district 
  now 
  

   covered 
  by 
  the 
  sea, 
  and 
  the 
  materials 
  indicate 
  a 
  constant 
  

   rejuvenation 
  of 
  a 
  land 
  (through 
  isostatic 
  adjustment?) 
  

   by 
  upheaval, 
  through 
  faulting. 
  Also 
  in 
  several 
  of 
  the 
  

   present 
  land 
  areas 
  which 
  were 
  once 
  parts 
  of 
  the 
  North 
  

   Atlantic 
  land, 
  as 
  in 
  Scotland, 
  Norway, 
  and 
  Spitzbergen, 
  

   faulting 
  is 
  a 
  common 
  phenomenon 
  of 
  Devonian 
  time, 
  and 
  

   in 
  the 
  two 
  first 
  mentioned 
  countries 
  it 
  is 
  locally 
  con- 
  

   nected 
  with 
  volcanic 
  activity. 
  Of 
  especial 
  interest 
  is 
  the 
  

   volcanic 
  activity 
  of 
  the 
  Kristiania 
  region, 
  probably 
  be- 
  

   longing 
  to 
  very 
  early 
  Devonian 
  time 
  and 
  not 
  to 
  Carboni- 
  

   ferous 
  time 
  as 
  stated 
  in 
  text-books, 
  because 
  we 
  find 
  here 
  

   in 
  a 
  small 
  district 
  an 
  astonishing 
  variety 
  of 
  rocks, 
  abys- 
  

   sal 
  and 
  volcanic, 
  which 
  have 
  gained 
  a 
  world-wide 
  repu- 
  

   tation 
  among 
  penologists. 
  

  

  The 
  shore-line 
  of 
  the 
  Devonian 
  continent 
  was 
  moved 
  

   very 
  considerably 
  to 
  the 
  northwest' 
  both 
  on 
  the 
  south- 
  

   eastern 
  and 
  the 
  northwestern 
  side, 
  from 
  Lower 
  to 
  Upper 
  

   Devonian 
  time. 
  This 
  movement 
  on 
  the 
  American 
  side 
  

   is 
  very 
  distinct 
  in 
  Ellesmereland, 
  where 
  the 
  lower 
  and 
  

   middle 
  part 
  of 
  the 
  Devonian 
  period 
  is 
  represented 
  by 
  

   richly 
  fossiliferous 
  marine 
  beds, 
  the 
  Upper 
  Devonian 
  by 
  

  

  