﻿APR. 
  4, 
  1922 
  brouwer: 
  tectonic 
  features 
  dutch 
  east 
  indies 
  173 
  

  

  crustal 
  movements 
  in 
  the 
  East 
  Indian 
  region 
  are 
  only 
  a 
  younger 
  stage 
  

   and 
  a 
  direct 
  continuation 
  of 
  the 
  Tertiary 
  crustal 
  movements. 
  The 
  

   Tertiary 
  folds 
  and 
  overthrusts 
  which 
  were 
  formed 
  at 
  relatively 
  great 
  

   depth 
  are 
  now 
  visible 
  at 
  the 
  surface, 
  but 
  the 
  fissured 
  and 
  faulted 
  

   crust 
  that 
  once 
  lay 
  above 
  them 
  has 
  been 
  removed 
  by 
  erosion. 
  On 
  the 
  

   other 
  hand, 
  the 
  tectonic 
  features 
  due 
  to 
  late 
  deformation 
  near 
  the 
  

   earth's 
  surface 
  during 
  the 
  younger 
  stage 
  of 
  mountain-building 
  have 
  re- 
  

   mained 
  visible 
  and 
  are 
  manifested 
  in 
  the 
  fissured 
  and 
  faulted 
  crust, 
  

   while 
  the 
  accompanying 
  folds 
  and 
  overthrusts 
  remain 
  invisible 
  at 
  

   greater 
  depths. 
  Thus, 
  we 
  believe 
  that 
  the 
  displacements, 
  evidence 
  of 
  

   which 
  is 
  now 
  seen 
  at 
  the 
  surface, 
  are 
  in 
  part 
  the 
  result 
  of 
  the 
  continua- 
  

   tion 
  of 
  movement 
  at 
  greater 
  depths 
  and 
  that 
  the 
  visible 
  traces 
  of 
  the 
  

   different 
  stages 
  of 
  crustal 
  movement 
  since 
  Tertiary 
  time 
  are 
  mutually 
  

   complementary. 
  A 
  comparison 
  of 
  these 
  stages 
  affords 
  a 
  better 
  under- 
  

   standing 
  of 
  the 
  mountain-building 
  process. 
  

  

  The 
  evolution 
  of 
  the 
  region 
  during 
  Paleozoic 
  and 
  Mesozoic 
  time 
  is 
  

   not 
  well 
  known, 
  but 
  the 
  widespread 
  occurrence 
  of 
  Mesozoic 
  deposits, 
  

   which 
  resemble 
  in 
  nearly 
  every 
  lithologic 
  respect 
  the 
  recent 
  deep-sea 
  

   oozes, 
  proves 
  that 
  already 
  in 
  Mesozoic 
  time 
  deep-sea 
  basins 
  were 
  

   present 
  in 
  the 
  region. 
  Thus 
  certain 
  red 
  clay 
  shales 
  with 
  radiolaria 
  and 
  

   radiolarian 
  hornstones 
  are 
  the 
  lithologic 
  equivalents 
  of 
  the 
  Recent 
  

   red 
  clay 
  and 
  radiolarian 
  ooze 
  formed 
  in 
  deep 
  seas 
  of 
  the 
  present 
  day. 
  

   The 
  hornstones 
  in 
  places 
  contain 
  nodules 
  of 
  manganese, 
  some 
  of 
  which 
  

   have 
  a 
  concentric 
  structure, 
  and 
  teeth 
  of 
  sharks 
  have 
  been 
  discovered 
  

   in 
  places. 
  These 
  deposits 
  prove 
  that 
  very 
  important 
  movements 
  of 
  the 
  

   earth's 
  crust 
  must 
  have 
  taken 
  place 
  since 
  Mesozoic 
  time; 
  movements 
  

   sufficiently 
  great 
  to 
  bring 
  deposits 
  formed 
  at 
  depths 
  of 
  5,000 
  meters 
  or 
  

   more 
  to 
  heights 
  of 
  more 
  than 
  1,000 
  meters 
  above 
  the 
  surface 
  of 
  the 
  sea. 
  

   It 
  is 
  permissible 
  to 
  conclude 
  that 
  the 
  process 
  of 
  mountain-building 
  

   in 
  the 
  East 
  Indian 
  Archipelago 
  bears 
  much 
  resemblance 
  to 
  that 
  of 
  

   other 
  Alpine 
  mountain 
  ranges, 
  such 
  as 
  the 
  Himalayas 
  and 
  the 
  Alps. 
  

   In 
  the 
  Mediterranean 
  region 
  of 
  Europe 
  it 
  has 
  been 
  possible 
  to 
  recon- 
  

   struct 
  theoretically 
  different 
  Mesozoic 
  geanticlines 
  and 
  geosynclines, 
  

   with 
  the 
  aid 
  of 
  stratigraphic 
  data, 
  when 
  it 
  was 
  once 
  realized 
  that 
  great 
  

   over-thrust 
  sheets 
  had 
  been 
  pushed 
  forward 
  long 
  distances 
  from 
  their 
  

   original 
  sites. 
  The 
  study 
  of 
  the 
  Recent 
  crustal 
  movements 
  in 
  the 
  

   rows 
  of 
  islands 
  of 
  eastern 
  Asia 
  and 
  Oceania 
  suggests 
  what 
  may 
  have 
  

   been 
  the 
  embryonic 
  stage 
  of 
  Alpine 
  mountain 
  ranges 
  when 
  (in 
  earlier 
  

   periods) 
  a 
  somewhat 
  similar 
  distribution 
  of 
  land 
  and 
  water 
  prevailed.^ 
  

   2 
  E. 
  Argand. 
  Sur 
  I'arc 
  des 
  Alpes 
  occidentales 
  . 
  Eclog. 
  Geol. 
  Helv. 
  14:145. 
  1916. 
  

  

  