﻿2 
  0. 
  Holtedalil 
  — 
  Paleo 
  geography, 
  etc. 
  

  

  bracing, 
  besides 
  parts 
  of 
  North 
  America, 
  European 
  and 
  

   Arctic 
  European 
  districts 
  also. 
  

  

  For 
  the 
  regions 
  in 
  which 
  the 
  present 
  author 
  has 
  made 
  

   personal 
  investigations, 
  the 
  Scandinavian 
  Peninsula 
  1 
  and 
  

   the 
  Arctic 
  districts, 
  2 
  to 
  the 
  north, 
  the 
  maps 
  mentioned 
  

   are 
  generally 
  not 
  very 
  satisfactory, 
  and 
  especially 
  for 
  

   older 
  Paleozoic 
  times, 
  and 
  as 
  a 
  good 
  deal 
  of 
  knowledge 
  

   concerning 
  the 
  stratigraphy 
  of 
  northern 
  lands 
  has 
  been 
  

   accumulated 
  during 
  recent 
  years, 
  an 
  attempt 
  is 
  here 
  

   made 
  to 
  present 
  new 
  maps 
  illustrating 
  certain 
  Paleozoic 
  

   geographies 
  of 
  those 
  regions. 
  As 
  has 
  so 
  eminently 
  been 
  

   shown 
  by 
  American 
  students 
  of 
  paleogeography, 
  the 
  de- 
  

   ciphering 
  of 
  the 
  geography 
  of 
  the 
  past 
  is 
  of 
  great 
  

   importance 
  to 
  several 
  fundamental 
  problems 
  in 
  geology: 
  

   for 
  the 
  natural 
  delimitation 
  of 
  the 
  periods, 
  to 
  show 
  the 
  

   extent 
  and 
  nature 
  of 
  crust 
  movements, 
  for 
  the 
  proper 
  

   understanding 
  of 
  the 
  geographic 
  relations 
  of 
  land 
  and 
  

   water, 
  and 
  the 
  development 
  of 
  life. 
  For 
  these 
  questions, 
  

   a 
  knowledge 
  of 
  the 
  paleogeographic 
  features, 
  not 
  only 
  of 
  

   a 
  single 
  continent 
  but 
  of 
  the 
  whole 
  earth, 
  is 
  of 
  great 
  

   importance 
  ; 
  therefore 
  this 
  contribution, 
  even 
  if 
  small, 
  

   may 
  be 
  of 
  interest. 
  

  

  The 
  fact 
  that 
  a 
  very 
  great 
  part 
  of 
  the 
  region 
  under 
  

   consideration 
  is 
  covered 
  by 
  the 
  ocean 
  adds 
  greatly 
  to 
  the 
  

   difficulties 
  of 
  presenting 
  reliable 
  maps 
  showing 
  the 
  dis- 
  

   tribution 
  of 
  the 
  ancient 
  lands 
  and 
  seas. 
  For 
  large 
  areas 
  

   in 
  each 
  one 
  of 
  the 
  maps 
  the 
  author 
  is 
  therefore 
  able 
  only 
  

   to 
  indicate 
  the 
  probable 
  conditions. 
  

  

  Description 
  of 
  the 
  Paleogeography. 
  

  

  Cambrian 
  Time 
  (see 
  figs. 
  1 
  and 
  2). 
  — 
  We 
  do 
  not 
  at 
  

   present 
  know 
  very 
  much 
  about 
  the 
  distribution 
  of 
  Cam- 
  

   brian 
  sediments 
  in 
  the 
  boreal 
  regions; 
  indeed, 
  so 
  little 
  

  

  1 
  Th. 
  Arldt, 
  in 
  his 
  review 
  of 
  paleogeographic 
  maps 
  in 
  ' 
  ' 
  Handbuch 
  der 
  

   Palaeogeographie, 
  " 
  Leipzig, 
  1917, 
  Bd. 
  1, 
  p. 
  21, 
  mentions 
  two 
  maps 
  by 
  

   Nathorst, 
  illustrating 
  "Kambrium 
  und 
  Silurmeer 
  in 
  Schweden, 
  ;; 
  pub- 
  

   lished 
  in 
  Nathorst 
  's 
  book, 
  "Sveriges 
  Geologi," 
  Stockholm, 
  1894, 
  pp. 
  138- 
  

   139. 
  The 
  maps 
  here 
  referred 
  to 
  are, 
  however, 
  not 
  paleogeographic, 
  but 
  

   maps 
  showing 
  the 
  present 
  distribution 
  of 
  Cambro-Silurian 
  sediments 
  in 
  

   two 
  Swedish 
  districts. 
  

  

  - 
  An 
  attempt 
  at 
  describing 
  the 
  geographic 
  development 
  of 
  the 
  Arctic 
  

   regions 
  in 
  Paleozoic 
  time, 
  without 
  maps, 
  has 
  been 
  made 
  by 
  O. 
  E. 
  Meyer 
  

   in 
  Neues 
  Jahrb. 
  f. 
  Min., 
  Beilage-Band 
  31, 
  1911, 
  in 
  an 
  article 
  stimulated 
  

   by 
  his 
  studies 
  on 
  a 
  part 
  of 
  the 
  paleontological 
  material 
  collected 
  during 
  

   the 
  second 
  Norwegian 
  expedition 
  in 
  the 
  "Fram. 
  " 
  Largely 
  because 
  of 
  

   later 
  investigations, 
  the 
  views 
  of 
  the 
  present 
  author 
  differ 
  in 
  many 
  respects 
  

   from 
  those 
  of 
  Meyer. 
  

  

  