﻿AGE 
  OF 
  THE 
  EARTH 
  — 
  CHAMBERLIN 
  AND 
  OTHERS. 
  251 
  

  

  phere 
  of 
  the 
  earth. 
  15 
  The 
  first 
  source 
  brought 
  one 
  type 
  of 
  solutions, 
  

   the 
  second 
  another, 
  and 
  the 
  third 
  added 
  water 
  that 
  was 
  essentially 
  

   fresh. 
  Under 
  this 
  view 
  it 
  is 
  obvious 
  that 
  until 
  this 
  complex 
  of 
  

   sources 
  and 
  variations 
  has 
  been 
  worked 
  out 
  the 
  present 
  rate 
  of 
  acces- 
  

   sion 
  has 
  no 
  claims 
  to 
  be 
  regarded 
  as 
  a 
  trustworthy 
  divisor 
  for 
  ascer- 
  

   taining 
  the 
  total 
  period 
  of 
  activity. 
  

  

  There 
  are 
  also 
  two 
  rather 
  radically 
  different 
  methods 
  of 
  dealing 
  

   with 
  the 
  geo-chemical 
  evolution 
  of 
  the 
  ocean. 
  These 
  are 
  not 
  neces- 
  

   sarily 
  connected 
  with 
  the 
  preceding 
  differences 
  of 
  view, 
  but 
  as 
  a 
  

   matter 
  of 
  fact 
  they 
  are 
  closely 
  associated 
  with 
  them. 
  

  

  The 
  first 
  of 
  these 
  — 
  associated 
  with 
  the 
  older 
  cosmological 
  view 
  — 
  

   takes 
  (a) 
  for 
  its 
  start 
  the 
  concept 
  of 
  a 
  universal 
  crust 
  acted 
  upon 
  

   from 
  without 
  by 
  an 
  atmosphere 
  and 
  hydrosphere, 
  (5) 
  for 
  its 
  middle 
  

   factor 
  the 
  streams, 
  and 
  (c) 
  for 
  its 
  end 
  products 
  the 
  sediments 
  and 
  

   the 
  ocean. 
  The 
  matter 
  in 
  the 
  sediments 
  and 
  in 
  the 
  ocean 
  taken 
  to- 
  

   gether 
  are 
  supposed 
  to 
  match 
  the 
  loss 
  of 
  the 
  crust 
  by 
  decomposition 
  

   and 
  wear. 
  Under 
  this 
  view 
  any 
  real 
  failure 
  to 
  so 
  match 
  is 
  a 
  dis- 
  

   crepancy 
  to 
  be 
  accounted 
  for. 
  In 
  the 
  special 
  problem 
  in 
  hand 
  the 
  

   sodium 
  in 
  the 
  ocean, 
  together 
  with 
  the 
  sodium 
  that 
  remains 
  in 
  the 
  

   sediments, 
  should 
  match 
  the 
  sodium 
  once 
  in 
  the 
  denuded 
  rocks 
  of 
  

   the 
  crust. 
  So, 
  also, 
  the 
  other 
  elements 
  of 
  the 
  crust 
  should 
  appear 
  

   in 
  due 
  proportion 
  in 
  the 
  sediments 
  and 
  the 
  ocean. 
  It 
  is 
  recognized 
  

   in 
  the 
  cases 
  of 
  calcium, 
  magnesium, 
  potassium, 
  silica, 
  and 
  other 
  ele- 
  

   ments 
  that 
  there 
  are 
  reversals 
  of 
  action 
  by 
  which 
  these 
  elements 
  go 
  

   back 
  into 
  the 
  solid 
  state 
  as 
  new 
  sediments, 
  but 
  it 
  is 
  held 
  that 
  sodium 
  

   does 
  not 
  return 
  to 
  the 
  solid 
  state 
  in 
  the 
  sediments 
  in 
  a 
  similar 
  

   chemico-physical 
  cyclic 
  way, 
  to 
  any 
  appreciable 
  degree. 
  Thus 
  the 
  

   sodium 
  now 
  in 
  the 
  ocean 
  is 
  held 
  to 
  represent 
  the 
  accumulation 
  of 
  

   all 
  the 
  geologic 
  ages, 
  and 
  this 
  total 
  accumulation 
  divided 
  by 
  the 
  

   rate 
  at 
  which 
  the 
  present 
  streams 
  are 
  carrying 
  sodium 
  down 
  to 
  the 
  

   sea 
  is 
  held 
  to 
  give 
  the 
  age 
  of 
  the 
  ocean, 
  barring 
  some 
  corrections 
  to 
  

   be 
  noted 
  later. 
  The 
  crux 
  of 
  the 
  whole 
  issue 
  of 
  age 
  lies 
  in 
  the 
  

   validity 
  of 
  these 
  concepts, 
  particularly 
  the 
  irreversibility 
  of 
  the 
  

   sodium. 
  

  

  The 
  other 
  view 
  is 
  far 
  less 
  simple. 
  It 
  looks 
  upon 
  the 
  hydrosphere, 
  

   of 
  which 
  the 
  ocean 
  is 
  the 
  chief 
  concentration, 
  as 
  only 
  the 
  liquid 
  phase 
  

   of 
  a 
  solid-liquid-gaseous 
  cycle 
  through 
  which 
  the 
  earth 
  substances 
  

   are 
  passing. 
  It 
  is 
  held 
  that 
  the 
  earth 
  is 
  perpetually 
  undergoing 
  self- 
  

   metamorphism 
  in 
  all 
  its 
  parts. 
  This 
  metamorphism 
  takes 
  place 
  in 
  a 
  

   multitude 
  of 
  ways, 
  each 
  unit 
  doing 
  its 
  part, 
  in 
  its 
  own 
  place, 
  in 
  its 
  

   own 
  way, 
  and 
  at 
  its 
  own 
  rate. 
  Each 
  unit 
  passes 
  through 
  its 
  own 
  

   cycles 
  of 
  liquid-solid-gaseous 
  states 
  according 
  as 
  its 
  nature, 
  its 
  con- 
  

   tacts, 
  and 
  conditions 
  determine. 
  Its 
  career 
  is 
  wholly 
  dependent 
  on 
  

   its 
  own 
  succession 
  of 
  conditions, 
  and 
  is 
  only 
  affected 
  by 
  what 
  other 
  

  

  15 
  "The 
  origin 
  of 
  the 
  earth," 
  The 
  University 
  of 
  Chicago 
  Press 
  (1916), 
  pp. 
  19-21. 
  

  

  