﻿248 
  ANNUAL, 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1922. 
  

  

  of 
  these 
  is 
  not 
  yet 
  complete 
  — 
  or 
  even 
  wholly 
  satisfactory 
  so 
  far 
  as 
  it 
  

   has 
  gone 
  — 
  but 
  the 
  leading 
  workers 
  in 
  this 
  field 
  recognize 
  six, 
  eight, 
  

   or 
  more 
  great 
  stages. 
  This 
  pre-Cambrian 
  factor 
  is 
  thus 
  certainly 
  

   great, 
  but 
  just 
  how 
  great 
  is 
  yet 
  undetermined. 
  

  

  The 
  mere 
  extension 
  of 
  the 
  sediments 
  downward 
  in 
  this 
  large 
  

   degree 
  is 
  not, 
  however, 
  the 
  most 
  significant 
  feature 
  of 
  this 
  recent 
  

   work. 
  Great 
  granitic 
  series 
  form 
  a 
  prominent 
  feature 
  of 
  these 
  lower 
  

   terranes. 
  These 
  were 
  formerly 
  taken 
  to 
  be 
  parts 
  of 
  "the 
  original 
  

   crust." 
  They 
  have 
  been 
  found, 
  however, 
  to 
  consist 
  of 
  remarkable 
  

   intrusions 
  into 
  earlier 
  series 
  made 
  up 
  of 
  sediments, 
  volcanic 
  debris, 
  

   and 
  surface 
  lava 
  flows. 
  The 
  granites 
  are 
  not 
  evidence 
  of 
  " 
  the 
  origi- 
  

   nal 
  crust 
  of 
  the 
  molten 
  globe." 
  Nor 
  does 
  there 
  seem 
  to 
  be 
  any 
  other 
  

   trustworthy 
  evidence 
  of 
  " 
  an 
  original 
  crust." 
  Thus 
  observational 
  

   evidence 
  does 
  not 
  give 
  the 
  depth 
  at 
  which 
  the 
  bottom 
  of 
  the 
  column 
  

   of 
  sediments 
  is 
  to 
  be 
  found, 
  and 
  theory 
  is 
  perhaps 
  as 
  favorable 
  to 
  a 
  

   depth 
  of 
  a 
  thousand 
  or 
  two 
  thousand 
  miles 
  as 
  any 
  shallower 
  depth. 
  

   A 
  reliable 
  starting 
  point 
  for 
  reckoning 
  the 
  total 
  thickness 
  of 
  the 
  

   sediments 
  is 
  not 
  available. 
  

  

  THE 
  TESTIMONY 
  OF 
  THE 
  SOLUTIONS. 
  13 
  

  

  In 
  the 
  effort 
  to 
  find 
  the 
  earth's 
  age 
  by 
  means 
  of 
  sediments 
  advan- 
  

   tage 
  may 
  be 
  taken 
  of 
  the 
  fact 
  that 
  each 
  deposit 
  makes 
  its 
  own 
  indi- 
  

   vidual 
  contribution. 
  It 
  is 
  thus 
  possible 
  to 
  sum 
  up 
  as 
  many 
  of 
  these 
  

   separate 
  contributions 
  as 
  can 
  be 
  measured 
  satisfactorily 
  and 
  rest 
  the 
  

   case 
  there, 
  leaving 
  what 
  remains 
  of 
  the 
  earth's 
  age 
  to 
  be 
  found 
  out 
  

   later 
  or 
  to 
  be 
  guessed 
  at 
  or 
  to 
  be 
  ignored. 
  But 
  when 
  the 
  inquiry 
  

   turns 
  to 
  the 
  solutions 
  it 
  must 
  face 
  the 
  fact 
  that 
  the 
  contributions 
  of 
  

   each 
  stage 
  have 
  been 
  mingled 
  with 
  those 
  of 
  all 
  other 
  stages 
  and 
  the 
  

   record 
  to 
  be 
  measured 
  is 
  thus 
  an 
  indivisible 
  unit. 
  If 
  the 
  ocean, 
  con- 
  

   sidered 
  as 
  such 
  record, 
  can 
  be 
  used 
  to 
  measure 
  age 
  at 
  all, 
  it 
  is 
  the 
  

   total 
  age 
  of 
  the 
  ocean. 
  This 
  total 
  age 
  of 
  the 
  ocean 
  can 
  not 
  be 
  ex- 
  

   pected 
  to 
  tally 
  with 
  the 
  age 
  found 
  from 
  an 
  unknown 
  fraction 
  of 
  

   sediments. 
  

  

  The 
  basis 
  of 
  estimating 
  the 
  age 
  of 
  the 
  ocean. 
  — 
  The 
  interpreta- 
  

   tion 
  of 
  the 
  time 
  occupied 
  in 
  the 
  concentration 
  of 
  solutions 
  in 
  the 
  

   ocean 
  hangs 
  on 
  the 
  assumptions 
  made 
  relative 
  to 
  its 
  origin 
  and 
  to 
  

   the 
  entire 
  history 
  of 
  the 
  earth's 
  waters 
  on 
  land 
  and 
  sea 
  alike. 
  This 
  

   includes 
  the 
  volume 
  of 
  the 
  waters 
  at 
  the 
  start 
  and 
  all 
  along; 
  it 
  in- 
  

   cludes 
  the 
  metamorphic 
  solutions 
  from 
  within 
  the 
  earth 
  as 
  well 
  as 
  

  

  13 
  Only 
  a 
  brief 
  general 
  statement 
  could 
  be 
  made 
  at 
  the 
  Symposium 
  for 
  lack 
  of 
  time. 
  

   Adequate 
  citation 
  of 
  evidence 
  or 
  of 
  authority 
  or 
  elaboration 
  of 
  critical 
  points 
  was 
  imprac- 
  

   ticable. 
  The 
  printed 
  text 
  gives 
  somewhat 
  more 
  liberty 
  and 
  I 
  have 
  taken 
  advantage 
  of 
  it 
  

   to 
  a 
  limited 
  extent 
  and 
  have 
  recast 
  this 
  part 
  of 
  the 
  text 
  to 
  accommodate 
  it 
  to 
  this. 
  I 
  am 
  

   greatly 
  indebted 
  to 
  Dr. 
  T. 
  Wayland 
  Vaughan. 
  United 
  States 
  geologist 
  in 
  charge 
  of 
  investi- 
  

   gations 
  on 
  sediments, 
  for 
  aid 
  in 
  securing 
  documents 
  and 
  personal 
  statements 
  from 
  the 
  

   departments 
  of 
  our 
  general 
  Government 
  and 
  from 
  its 
  officials 
  engaged 
  in 
  investigations 
  

   bearing 
  on 
  the 
  question 
  in 
  hand. 
  

  

  