﻿42 
  THEOBALD 
  ." 
  GEOLOGY 
  OP 
  PEGU. 
  

  

  regur 
  and 
  trap, 
  than 
  that 
  many 
  trap 
  rocks 
  in 
  India 
  do 
  as 
  a 
  matter 
  of 
  

   fact 
  decompose 
  into 
  regur, 
  though 
  of 
  course 
  many 
  do 
  not, 
  the 
  result 
  

   being 
  simply 
  dependent 
  on 
  the 
  composition 
  of 
  the 
  trap 
  in 
  question; 
  and 
  

   hence, 
  of 
  course, 
  the 
  fact 
  of 
  much 
  trap 
  decomposing 
  into 
  quite 
  a 
  different 
  

   soil 
  was 
  quite 
  in 
  unison 
  with 
  the 
  admission 
  than 
  any 
  rock, 
  even 
  though 
  

   non-trappean 
  in 
  character, 
  might 
  give 
  rise 
  to 
  regur 
  if 
  its 
  composition 
  was 
  

   such 
  as 
  to 
  yield 
  the 
  requisite 
  elements. 
  The 
  fact 
  of 
  the 
  existence 
  of 
  

   hundreds 
  of 
  square 
  miles 
  of 
  regur 
  where 
  no 
  trap 
  is 
  now 
  known, 
  though 
  not 
  

   without 
  force, 
  has 
  never 
  appeared 
  to 
  me 
  so 
  conclusive 
  as 
  to 
  some 
  of 
  my 
  

   colleagues, 
  since 
  the 
  decomposition 
  and 
  removal 
  of 
  the 
  trap 
  is 
  antecedently 
  

   involved, 
  in 
  the 
  very 
  genesis 
  of 
  regur 
  (from 
  trap) 
  ; 
  and 
  it 
  is 
  only 
  conse- 
  

   quently 
  in 
  the 
  great 
  trap 
  regions, 
  and 
  on 
  their 
  skirts, 
  that 
  the 
  actual 
  

   derivation 
  can 
  be 
  ordinarily 
  witnessed 
  of 
  one 
  from 
  the 
  other. 
  I 
  cannot 
  

   here 
  do 
  better 
  than 
  quote 
  from 
  the 
  Gazetteer 
  of 
  the 
  Central 
  Provinces, 
  

   the 
  views 
  so 
  succinctly 
  expressed 
  on 
  the 
  subject 
  by 
  Dr. 
  Oldham, 
  under 
  

   the 
  head 
  f 
  Regur/ 
  page 
  XLVII 
  : 
  " 
  E-egur 
  can 
  then 
  be 
  formed 
  wherever 
  

   a 
  truly 
  argillaceous 
  soil 
  is 
  formed, 
  and 
  its 
  general, 
  but 
  by 
  no 
  means 
  

   universal 
  absence 
  over 
  the 
  metamorphic 
  and 
  other 
  rocks, 
  is 
  easily 
  ac- 
  

   counted 
  for 
  by 
  the 
  fact 
  that 
  these 
  rocks 
  for 
  the 
  most 
  part 
  yield 
  sandy, 
  

   not 
  clayey 
  soils/' 
  

  

  It 
  remains, 
  however, 
  that 
  as 
  a 
  matter 
  of 
  fact, 
  it 
  would 
  seem 
  that 
  

   the 
  trap 
  rocks 
  of 
  India 
  have 
  more 
  largely 
  and 
  directly 
  contributed 
  to 
  the 
  

   formation 
  of 
  regur, 
  than 
  any 
  other 
  description 
  of 
  rocks, 
  whence, 
  the 
  too 
  

   hasty 
  assumption 
  that 
  all 
  regur 
  was 
  derived 
  from 
  trap. 
  Dr. 
  Oldham 
  

   again 
  remarks 
  {Joe. 
  cit) 
  — 
  "The 
  color 
  of 
  this 
  soil, 
  often 
  a 
  deep 
  and 
  well 
  

   marked 
  black, 
  with 
  every 
  variation 
  from 
  this 
  to 
  a 
  brownish 
  black, 
  would 
  

   appear 
  to 
  be 
  solely 
  due 
  to 
  an 
  admixture 
  of 
  vegetable 
  (organic) 
  matter 
  

   in 
  a 
  soil 
  originally 
  very 
  clayey." 
  This 
  doubtless 
  is 
  often, 
  perhaps 
  gene- 
  

   rally 
  the 
  case, 
  but 
  a 
  series 
  of 
  analysis 
  are, 
  I 
  think, 
  required 
  to 
  show 
  that 
  to 
  

   no 
  other 
  cause 
  than 
  this 
  is 
  the 
  dark 
  color 
  due, 
  since 
  the 
  massive 
  trap 
  roc^ 
  

   weathers 
  black 
  on 
  the 
  surface, 
  which 
  must 
  be 
  due 
  not 
  to 
  the 
  presence 
  in 
  

   ( 
  230 
  ) 
  

  

  