﻿Diastrophism 
  in 
  Atlantic- 
  Arctic 
  Region. 
  9 
  

  

  donian 
  deformation 
  is 
  now 
  in 
  full 
  development 
  in 
  regions 
  

   that 
  in 
  Lower 
  Silurian 
  time 
  were 
  covered 
  by 
  the 
  sea, 
  as 
  

   for 
  instance, 
  in 
  the 
  northwestern 
  part 
  of 
  southern 
  

   Norway. 
  The 
  very 
  important 
  recent 
  discoveries 
  of 
  un- 
  

   metamorphosed 
  sandstones 
  of 
  Downtonian 
  age, 
  resting 
  

   nnconformably 
  upon 
  the 
  deeply 
  eroded 
  remnants 
  of 
  

   Caledonian 
  mountain 
  ranges, 
  in 
  Spitzbergen 
  and 
  in 
  

   southwestern 
  Norway, 
  make 
  it 
  very 
  probable 
  that 
  this 
  

   gigantic 
  deformation 
  began 
  rather 
  early 
  in 
  the 
  Silurian, 
  

   that 
  is, 
  after 
  Llandovery 
  time. 
  Is 
  it 
  not, 
  then, 
  natural 
  

   to 
  infer 
  that 
  the 
  Middle 
  Silurian 
  transgression 
  is 
  a 
  

   direct 
  concomitant 
  of 
  this 
  rising 
  of 
  a 
  land, 
  a 
  rising 
  that 
  

   must 
  be 
  supposed 
  to 
  have 
  taken 
  place, 
  to 
  a 
  large 
  degree, 
  

   in 
  areas 
  previously 
  covered 
  by 
  the 
  sea? 
  

  

  The 
  Caledonian 
  deformation 
  must 
  have 
  continued 
  for 
  

   a 
  very 
  considerable 
  time. 
  In 
  southern 
  Scotland 
  and 
  

   England 
  the 
  chief 
  movement 
  took 
  place 
  immediately 
  pre- 
  

   ceding 
  the 
  deposition 
  of 
  the 
  Lower 
  Old 
  Red, 
  as 
  here 
  the 
  

   Downtonian 
  is 
  also 
  folded. 
  On 
  the 
  other 
  hand, 
  in 
  the 
  

   Kristiania 
  region 
  the 
  Downtonian 
  sandstones 
  pass 
  grad- 
  

   ually 
  into 
  marine 
  Ludlow 
  beds 
  and 
  all 
  of 
  these 
  strata 
  

   have 
  been 
  subjected 
  to 
  considerable 
  folding. 
  In 
  fact, 
  

   there 
  can 
  be 
  no 
  doubt 
  that 
  in 
  the 
  arc 
  of 
  the 
  geosyncline 
  

   the 
  deformative 
  movement 
  has 
  been 
  vertical 
  to 
  the 
  axes 
  

   of 
  folding. 
  This 
  zonal 
  wandering 
  of 
  the 
  axes 
  of 
  move- 
  

   ment 
  is, 
  as 
  is 
  well 
  known, 
  a 
  phenomenon 
  observed 
  also 
  in 
  

   other 
  mountain 
  belts. 
  

  

  In 
  figure 
  7 
  I 
  have 
  shown, 
  in 
  a 
  very 
  generalized 
  sketch, 
  

   how 
  this 
  spreading 
  of 
  the 
  deformation 
  across 
  present 
  

   southern 
  Norway 
  may 
  be 
  thought 
  to 
  have 
  taken 
  place. 
  

   In 
  this 
  connection 
  it 
  is 
  of 
  great 
  interest 
  to 
  note 
  that 
  

   somewhat 
  similar 
  conditions 
  are 
  also 
  known 
  in 
  Scotland. 
  

   Here, 
  at 
  Stonehaven, 
  not 
  far 
  to 
  the 
  north 
  on 
  the 
  east 
  

   coast, 
  the 
  Downtonian 
  rests 
  unconformably 
  on 
  intensely 
  

   folded 
  rocks 
  of 
  very 
  old 
  (Upper 
  Cambrian?) 
  age, 
  and 
  

   passes 
  upwards 
  through 
  a 
  transition 
  series 
  into 
  Lower 
  

   Old 
  Red 
  Sandstone. 
  Southwest 
  of 
  Edinburgh, 
  as 
  in 
  

   England, 
  the 
  Downtonian 
  passes 
  conformably 
  below 
  into 
  

   marine 
  beds 
  (as 
  at 
  Kristiania), 
  and 
  above 
  is 
  separated 
  

   from 
  the 
  true 
  Old 
  Red 
  by 
  a 
  marked 
  unconformity. 
  

  

  At 
  present 
  I 
  will 
  not 
  go 
  into 
  detail 
  as 
  to 
  the 
  varying 
  

   nature 
  of 
  the 
  Caledonian 
  deformation 
  in 
  the 
  Scandina- 
  

   vian 
  Peninsula, 
  where 
  much 
  work 
  has 
  been 
  done 
  during 
  

   recent 
  years 
  to 
  clear 
  up 
  the 
  tectonic 
  problems 
  connected 
  

   with 
  that 
  imposing 
  revolution. 
  But 
  I 
  must 
  point 
  out 
  

  

  