﻿6 
  1 
  THEOBALD 
  '. 
  GEOLOGY 
  OF 
  PEGU. 
  

  

  South-west 
  too 
  of 
  Tamagon 
  on 
  the 
  Puday 
  stream, 
  and 
  thence 
  as 
  far 
  as 
  

   the 
  Myouk-naweng 
  stream, 
  fossil- 
  wood 
  is 
  abundant 
  ; 
  though 
  from 
  the 
  

   great 
  denudation 
  the 
  bed 
  has 
  here 
  undergone, 
  the 
  logs 
  are 
  more 
  broken 
  

   than 
  elsewhere, 
  though 
  often 
  four 
  feet 
  or 
  so 
  in 
  length. 
  

  

  This 
  wood 
  is 
  generally 
  well 
  silicified, 
  though 
  subject 
  to 
  decompose 
  

   from 
  absorbing 
  atmospheric 
  water, 
  whereby 
  the 
  more 
  or 
  less 
  hyaline 
  silica 
  

   is 
  converted 
  into 
  the 
  opaque 
  and 
  earthy 
  hydrate, 
  which 
  readily 
  disinte- 
  

   grates 
  and 
  crumbles 
  away. 
  Prior 
  to 
  silicification, 
  however, 
  the 
  wood 
  had 
  

   to 
  a 
  considerable 
  extent 
  become 
  decayed, 
  probably 
  from 
  long 
  immersion 
  in 
  

   water. 
  We 
  may 
  conjecture 
  that 
  the 
  trunks 
  of 
  trees 
  in 
  question 
  floated 
  

   about 
  till 
  waterlogged 
  in 
  shallow 
  lakes, 
  in 
  which, 
  on 
  sinking, 
  they 
  

   became 
  mineralized 
  through 
  the 
  agency 
  of 
  springs 
  holding 
  silica 
  in 
  

   solution 
  ; 
  and 
  it 
  seems 
  not 
  improbable 
  to 
  connect 
  the 
  existence 
  of 
  such 
  

   springs 
  with 
  the 
  volcanic 
  activity 
  which 
  we 
  know 
  prevailed 
  about 
  this 
  

   time, 
  as 
  indicated 
  by 
  the 
  extinct 
  volcanic 
  vent 
  of 
  Puppadoung. 
  Some 
  

   unusually 
  well 
  preserved 
  specimens 
  of 
  this 
  wood 
  from 
  the 
  Prome 
  district 
  

   were 
  taken 
  home 
  by 
  me 
  in 
  1867, 
  and 
  examined 
  microscopically 
  at 
  the 
  

   British 
  Museum 
  (by, 
  if 
  I 
  remember 
  rightly, 
  M. 
  Carruthers), 
  but 
  

   from 
  the 
  decomposition 
  of 
  the 
  wood 
  prior 
  to 
  its 
  silieification, 
  and 
  the 
  

   consequent 
  obliteration 
  of 
  much 
  of 
  its 
  finer 
  structure, 
  all 
  that 
  could 
  be 
  

   pronounced 
  regarding 
  its 
  nature 
  was, 
  that 
  the 
  wood 
  was 
  exogenous 
  and 
  

   not 
  a 
  conifer, 
  as 
  I 
  had 
  surmised 
  might 
  be 
  the 
  case. 
  Dr. 
  Buckland 
  

   thought 
  the 
  wood 
  resembled 
  tamarind 
  wood, 
  though 
  on 
  what 
  grounds 
  

   he 
  does 
  not 
  state. 
  The 
  Burmese 
  consider 
  the 
  fossil-wood 
  to 
  be 
  identical 
  

   with 
  the 
  ' 
  Enjin' 
  tree 
  still 
  living 
  in 
  the 
  district, 
  and 
  some 
  of 
  it 
  they 
  

   refer 
  to 
  the 
  ' 
  Thiyah' 
  (skorea 
  oblusa) 
  ; 
  but 
  as 
  far 
  as 
  I 
  can 
  judge, 
  there 
  is 
  

   but 
  one 
  species 
  of 
  fossil 
  exogenous 
  wood 
  in 
  Pegu. 
  Endogenous 
  wood 
  is 
  

   unknown 
  to 
  me, 
  as 
  derived 
  from 
  this 
  bed. 
  I 
  have 
  seen 
  rolled 
  frag- 
  

   ments 
  of 
  it, 
  very 
  rarely, 
  from 
  the 
  modern 
  Irrawadi 
  gravels, 
  which 
  may 
  

   have 
  been 
  derived 
  either 
  from 
  this 
  bed 
  or 
  one 
  of 
  the 
  lower 
  beds 
  of 
  this 
  

   group 
  ; 
  but 
  in 
  Pegu, 
  fossil 
  endogenous 
  wood 
  is 
  undoubtedly 
  very 
  scarce. 
  

  

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