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  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1927 
  

  

  transformation 
  of 
  preexisting 
  rocks 
  of 
  the 
  earth's 
  crust, 
  and 
  the 
  re- 
  

   peated 
  overlaying 
  of 
  these 
  upon 
  other 
  regions, 
  alter 
  the 
  local 
  gravita- 
  

   tional 
  proportion. 
  Therewith 
  result 
  gravitational 
  readjustments 
  

   of 
  far-reaching 
  etfects. 
  The 
  increased 
  local 
  loading 
  through 
  the 
  

   heaping 
  up 
  of 
  newly 
  formed 
  rocks 
  creates 
  in 
  that 
  region 
  a 
  subsiding 
  

   movement 
  beneath 
  which 
  there 
  ensues 
  a 
  compensating 
  sideways 
  

   thrust. 
  The 
  thrust 
  results 
  in 
  an 
  upward 
  movement 
  of 
  the 
  earth's 
  

   crust 
  elsewhere. 
  Movements 
  of 
  the 
  earth's 
  crust 
  in 
  one 
  place 
  set 
  in 
  

   action 
  other 
  readjusting 
  movements 
  elsewhere. 
  These 
  readjustments 
  

   of 
  the 
  earth's 
  outer 
  shell 
  are 
  more 
  or 
  less 
  bound 
  up 
  with 
  the 
  parox- 
  

   ysms 
  of 
  earthquakes 
  and 
  of 
  volcanic 
  actions. 
  And 
  the 
  volcanic 
  

   reactions 
  continually 
  make 
  rise 
  new 
  masses 
  from 
  the 
  depths 
  to 
  the 
  

   earth's 
  surface 
  for 
  the 
  geological 
  action 
  of 
  the 
  atmosphere, 
  water, 
  ice, 
  

   and 
  organic 
  life 
  in 
  a 
  new 
  cycle. 
  

  

  The 
  building 
  of 
  the 
  long, 
  lofty 
  mountain 
  chains 
  stands 
  in 
  close 
  

   relationship 
  Avith 
  the 
  mass 
  movements 
  ensuing 
  from 
  the 
  action 
  of 
  the 
  

   hydrosphere 
  and 
  the 
  atmosphere. 
  In 
  the 
  uplifted 
  mountain 
  chains, 
  

   their 
  altitude 
  when 
  rightly 
  oriented 
  relative 
  to 
  prevailing 
  winds 
  

   richly 
  loaded 
  with 
  moisture 
  results 
  in 
  a 
  great 
  increase 
  of 
  rain. 
  Fur- 
  

   ther 
  the 
  surface 
  offered 
  to 
  weathering 
  is 
  much 
  greater 
  than 
  on 
  a 
  level 
  

   plain. 
  Because 
  of 
  the 
  increased 
  altitude 
  and 
  consequently 
  increased 
  

   fall 
  for 
  the 
  water, 
  the 
  movement 
  of 
  waters 
  in 
  their 
  channels 
  is 
  greatly 
  

   increased, 
  and 
  the 
  latter's 
  carrying 
  power 
  is 
  much 
  augmented. 
  In 
  

   the 
  neighboring 
  plains, 
  where 
  the 
  movement 
  and 
  consequently 
  trans- 
  

   porting 
  power 
  of 
  the 
  water 
  is 
  much 
  diminished, 
  the 
  decomposition 
  

   products, 
  due 
  to 
  weathering 
  and 
  abrasion, 
  will 
  be 
  heaped 
  up. 
  In 
  

   gathering 
  places, 
  in 
  geosynclines, 
  this 
  mass 
  of 
  matter 
  thus 
  dragged 
  

   down 
  from 
  the 
  higher 
  ranges 
  upon 
  sinking 
  sedimentation 
  plains, 
  

   serves 
  for 
  the 
  formation 
  of 
  thousands 
  of 
  meters 
  of 
  new 
  rocks. 
  Out 
  

   of 
  these 
  areas, 
  as 
  earth 
  history 
  repeatedly 
  shows, 
  new 
  mountains 
  

   come 
  into 
  existence 
  while 
  the 
  former 
  highlands 
  are 
  worn 
  in 
  propor- 
  

   tion 
  to 
  the 
  abrasive 
  action 
  of 
  the 
  water. 
  

  

  None 
  of 
  these 
  mass 
  movements 
  of 
  the 
  earth's 
  crust 
  occurs 
  and 
  

   works 
  independently. 
  All 
  these 
  life 
  expressions 
  interlock 
  with 
  each 
  

   other. 
  They 
  show 
  themselves 
  in 
  the 
  most 
  complicated 
  interrelation- 
  

   ships. 
  In 
  all 
  these 
  complicated 
  occurrences, 
  their 
  continual, 
  pulsat- 
  

   ing 
  work 
  forms 
  the 
  manifested 
  whole 
  of 
  this 
  earth's 
  life, 
  the 
  chang- 
  

   ing 
  episodes 
  of 
  which 
  the 
  rock-made 
  archives 
  of 
  the 
  earth 
  preserve. 
  

  

  Though 
  the 
  unity 
  and 
  heterogeneity 
  of 
  this 
  earth's 
  life 
  stands 
  

   clearly 
  before 
  us, 
  the 
  next 
  consideration 
  is 
  veiled 
  in 
  uncertainty 
  : 
  

   What 
  is 
  the 
  unique 
  actuating 
  impulse 
  which 
  leads 
  to 
  this 
  whole 
  inter- 
  

   acting 
  complex 
  of 
  the 
  life-assertions 
  of 
  this 
  earth 
  ? 
  What 
  originates 
  

   the 
  impulse 
  which 
  gives 
  to 
  the 
  earth's 
  body 
  the 
  movements 
  which 
  

   constitute 
  its 
  life? 
  

  

  