﻿GENERAL 
  STRATIGRAPHY. 
  33 
  

  

  III. 
  — 
  General 
  Stratigraphy. 
  

  

  I 
  will 
  now 
  preface 
  my 
  description 
  of 
  the 
  particular 
  groups 
  met 
  

   with 
  in 
  Pegu, 
  with 
  some 
  remarks 
  on 
  the 
  general 
  geological 
  constitution 
  

   of 
  the 
  valley 
  of 
  the 
  Irrawadi, 
  more 
  particularly 
  as 
  it 
  has 
  reacted 
  on 
  

   the 
  physical 
  configuration 
  of 
  the 
  surface; 
  Reference 
  may 
  also 
  be 
  made 
  

   to 
  previously 
  published 
  notices 
  by 
  myself, 
  in 
  the 
  Records 
  of 
  the 
  

   Geological 
  Survey 
  of 
  India, 
  Vol. 
  II, 
  page 
  79 
  ; 
  Vol. 
  Ill, 
  pages 
  17 
  and 
  

   72 
  ; 
  Vol. 
  IV, 
  page 
  33 
  ; 
  Vol. 
  V, 
  pages 
  79 
  and 
  120. 
  

  

  The 
  geological 
  history 
  of 
  Pegu 
  and 
  the 
  country 
  adjoining 
  it 
  (for 
  

   the 
  two 
  must 
  to 
  some 
  extent 
  be 
  included 
  in 
  any 
  general 
  and 
  com- 
  

   prehensive 
  review 
  of 
  the 
  past), 
  is 
  extremely 
  simple 
  as 
  regards 
  its 
  grander 
  

   and 
  more 
  cardinal 
  features, 
  a 
  simplicity 
  to 
  some 
  extent 
  indicated 
  and 
  

   portrayed 
  in 
  the 
  general 
  geographical 
  features 
  of 
  the 
  province 
  as 
  

   already 
  described; 
  and 
  what 
  is 
  true 
  of 
  the 
  lower 
  portion 
  of 
  the 
  

   Irrawadi 
  valley 
  will, 
  no 
  doubt, 
  largely 
  apply 
  to 
  the 
  upper 
  portion 
  also, 
  

   which 
  at 
  present 
  is 
  very 
  little 
  known, 
  save 
  in 
  the 
  immediate 
  vicinity 
  

   of 
  the 
  river. 
  

  

  In 
  both 
  the 
  Eastern 
  and 
  Western 
  Yomah, 
  we 
  have 
  an 
  instance 
  

   pure 
  and 
  simple, 
  as 
  far 
  as 
  possible, 
  of 
  the 
  formation 
  of 
  a 
  great 
  mountain 
  

   chain 
  through 
  the 
  direct 
  operation 
  of 
  lateral 
  pressure 
  ; 
  causing 
  a 
  fold- 
  

   ing 
  and, 
  as 
  a 
  result 
  therefrom, 
  an 
  elevation 
  of 
  the 
  sedimentary 
  beds, 
  

   along 
  a 
  line 
  or 
  lines 
  of 
  least 
  resistance, 
  which 
  lines, 
  or 
  the 
  principal 
  

   among 
  them, 
  coincide 
  in 
  direction 
  with 
  the 
  axes 
  of 
  the 
  mountain 
  

   chains 
  so 
  produced 
  ; 
  and 
  we 
  have 
  very 
  generally 
  wanting 
  in 
  the 
  "Western 
  

   or 
  Arakan 
  Yomah, 
  and 
  completely 
  so 
  in 
  the 
  Eastern 
  or 
  Pegu 
  Yomah, 
  

   any 
  complex 
  system 
  of 
  faulting 
  on 
  a 
  large 
  scale, 
  or 
  intrusion 
  of 
  igneous 
  

   rocks, 
  whether 
  in 
  a 
  solid 
  or 
  fluid 
  condition, 
  which 
  adds 
  such 
  an 
  element 
  

   of 
  complexity 
  to 
  the 
  historical 
  record 
  of 
  the 
  genesis 
  of 
  such 
  chains 
  

   as 
  the 
  Alps. 
  

  

  As 
  a 
  conjoint 
  result, 
  with 
  the 
  production 
  of 
  an 
  anticlinal 
  fold, 
  is 
  

   the 
  simultaneous 
  production 
  of 
  a 
  synclinal 
  trough 
  ; 
  and 
  in 
  this 
  dynami- 
  

   e 
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  221 
  ) 
  

  

  