﻿38 
  THEOBALD 
  : 
  GEOLOGY 
  OP 
  PEGU. 
  

  

  strata 
  seen 
  on 
  the 
  Western 
  side 
  of 
  the 
  range 
  was 
  confined 
  to 
  that 
  

   side 
  by 
  the 
  limitation 
  of 
  the 
  basin 
  of 
  deposition 
  by 
  the 
  range 
  in 
  question; 
  

   as 
  such 
  a 
  supposition 
  is 
  opposed 
  to 
  the 
  general 
  physical 
  features 
  and 
  

   history 
  of 
  the 
  entire 
  area 
  whereof 
  that 
  portion 
  of 
  the 
  range 
  at 
  present 
  

   in 
  question 
  forms 
  but 
  a 
  very 
  small 
  portion. 
  There 
  is 
  no 
  evidence 
  

   whatever 
  in 
  favor 
  of 
  the 
  idea 
  (a 
  strong 
  presumption, 
  however, 
  existing 
  

   against 
  it) 
  that 
  whereas 
  the 
  entire 
  series 
  of 
  deposits 
  from 
  the 
  Eocene 
  

   upwards 
  accumulated 
  in 
  a 
  broad 
  basin 
  of 
  deposition, 
  not 
  broken 
  up 
  by 
  

   the 
  formation 
  of 
  any 
  such 
  mountain 
  barrier 
  as 
  the 
  Arakan 
  "Range 
  till 
  a 
  

   subsequent 
  period, 
  yet 
  that 
  any 
  such 
  barrier 
  or 
  surface 
  of 
  deposition 
  

   as 
  would 
  be 
  requisite 
  to 
  account 
  for 
  the 
  restriction 
  of 
  the 
  Cretaceous 
  

   ^roup 
  to 
  the 
  limits 
  it 
  now 
  occupies 
  should 
  have 
  existed, 
  without 
  any 
  

   other 
  trace 
  of 
  its 
  existence 
  save 
  the 
  feature 
  under 
  notice, 
  which 
  seems 
  

   most 
  naturally 
  accounted 
  for 
  by 
  a 
  master-fault. 
  

  

  I 
  have 
  attempted 
  to 
  represent 
  in 
  a 
  diagrammatic 
  section 
  the 
  view 
  

   of 
  the 
  general 
  structural 
  features 
  (See 
  PL 
  I), 
  but 
  it 
  is 
  not 
  in 
  Pegu, 
  that 
  

   the 
  unravelling 
  of 
  the 
  relations 
  of 
  these 
  groups 
  to 
  each 
  other, 
  can 
  be 
  

   looked 
  for; 
  nor, 
  from 
  the 
  nature 
  of 
  the 
  country, 
  can 
  much 
  more 
  be 
  

   expected 
  to 
  the 
  North 
  in 
  Arakan, 
  where, 
  if 
  the 
  rocks 
  are 
  better 
  deve- 
  

   loped, 
  the 
  nature 
  of 
  the 
  ground 
  is 
  no 
  less 
  opposed 
  to 
  investigation 
  than 
  

  

  in 
  Pegu. 
  

  

  It 
  is 
  among 
  these 
  Triassic 
  rocks 
  that 
  the 
  largest 
  development 
  of 
  

   serpentine 
  occurs 
  ; 
  but 
  it 
  is 
  not 
  confined 
  to 
  them, 
  and 
  is 
  met 
  with 
  among 
  

   beds 
  classed 
  by 
  me 
  as 
  Negrais, 
  possibly 
  indicating 
  an 
  age 
  for 
  these 
  

   outbreaks 
  not 
  older 
  than 
  the 
  earliest 
  Tertiaries. 
  A 
  reference 
  to 
  the 
  map 
  

   will, 
  however, 
  best 
  serve 
  to 
  convey 
  an 
  idea 
  of 
  their 
  general 
  disposition 
  

   in 
  the 
  province. 
  

  

  In 
  the 
  Eastern 
  Yomah, 
  no 
  intrusive 
  rock 
  of 
  any 
  sort 
  occurs, 
  the 
  

   trappean 
  bed 
  near 
  Zen 
  and 
  elsewhere 
  not 
  falling 
  within 
  that 
  category, 
  

   though 
  in 
  hand-specimens 
  pieces 
  of 
  that 
  rock 
  might 
  readily 
  be 
  mistaken 
  

   for 
  an 
  intrusive 
  rock. 
  The 
  remarkable 
  occurrence 
  of 
  an 
  outcrop 
  of 
  

   trachyte 
  in 
  the 
  Bassein 
  district 
  will 
  be 
  described 
  in 
  another 
  place. 
  

  

  ( 
  220 
  ) 
  

  

  