﻿52 
  THEOBALD 
  : 
  GEOLOGY 
  0*" 
  PEGU. 
  

  

  Bengal, 
  appears 
  nearly 
  as 
  good 
  proof 
  of 
  the 
  stationary 
  or 
  rising 
  condition 
  

   of 
  the 
  Irrawadi 
  Delta 
  as 
  the 
  presence 
  of 
  this 
  important 
  group 
  in 
  Bengal 
  

   is 
  of 
  the 
  subsidence 
  of 
  the 
  area 
  occupied 
  by 
  it. 
  The 
  conditions 
  of 
  the 
  

   Delta 
  of 
  the 
  Irrawadi 
  correspond 
  very 
  closely, 
  however, 
  with 
  the 
  conditions 
  

   which 
  must 
  have 
  preceded 
  the 
  deposition 
  of 
  the 
  newer 
  alluvium 
  in 
  the 
  

   Gangetic 
  Delta 
  ; 
  and 
  all 
  that 
  is 
  wanted 
  besides 
  time, 
  to 
  make 
  the 
  Irrawadi 
  

   Delta 
  a 
  counterpart 
  of 
  that 
  of 
  the 
  Ganges 
  is, 
  that 
  it 
  should 
  be 
  subjected 
  

   to 
  an 
  equal 
  amount 
  of 
  subsidence 
  at 
  such 
  a 
  rate 
  as 
  to 
  allow 
  of 
  the 
  

   growth, 
  pari 
  passu, 
  of 
  the 
  newer 
  or 
  river 
  alluvium 
  over 
  the 
  surface 
  of 
  the 
  

   subsiding 
  land. 
  Of 
  this 
  there 
  is 
  no 
  trace, 
  and 
  subsidence 
  is 
  therefore 
  

   not 
  going 
  on. 
  The 
  alluvial 
  matter 
  which, 
  in 
  the 
  event 
  of 
  subsidence 
  of 
  

   the 
  delta, 
  would 
  become 
  effused 
  over 
  the 
  country, 
  building 
  it 
  up 
  at 
  top 
  

   in 
  a 
  ratio 
  approximating 
  to 
  the 
  rate 
  of 
  subsidence, 
  as 
  we 
  see 
  has 
  taken 
  

   place 
  in 
  Bengal, 
  is 
  in 
  Pegu 
  swept 
  out 
  to 
  sea, 
  and 
  being 
  spread 
  far 
  and 
  

   wide 
  in 
  the 
  troublous 
  Gulf 
  of 
  Martaban, 
  goes 
  to 
  form 
  a 
  portion 
  or 
  con- 
  

   tinuation 
  of 
  the 
  older 
  alluvial 
  bed, 
  the 
  growth 
  of 
  which, 
  though 
  checked 
  

   within 
  the 
  delta 
  by 
  its 
  elevation 
  beyond 
  the 
  waters 
  of 
  the 
  gulf, 
  yet 
  is 
  

   continued 
  beneath 
  those 
  waters, 
  and 
  follows 
  unchecked 
  the 
  ordinary 
  laws 
  

   of 
  growth 
  of 
  such 
  deposits. 
  It 
  is 
  impossible, 
  where 
  the 
  elevation 
  of 
  

   such 
  a 
  tract 
  as 
  a 
  delta 
  is 
  gradual, 
  to 
  point 
  to 
  any 
  actual 
  proof 
  of 
  such 
  

   process 
  more 
  tangible 
  or 
  satisfactory 
  than 
  that 
  above 
  given 
  ; 
  but 
  the 
  

   greater 
  inclination 
  of 
  the 
  dark 
  band 
  of 
  clay 
  previously 
  noticed 
  as 
  pre- 
  

   serving 
  a 
  greater 
  dip 
  to 
  the 
  South, 
  than 
  either 
  the 
  surface 
  of 
  the 
  land 
  

   or 
  the 
  existing 
  river, 
  is, 
  as 
  far 
  as 
  it 
  goes, 
  in 
  favour 
  of 
  an 
  elevatory 
  move- 
  

   ment 
  of 
  the 
  whole 
  country 
  whose 
  minimum 
  effect 
  is 
  felt 
  in 
  the 
  delta. 
  

   Along 
  the 
  Arakan 
  Coast, 
  the 
  elevation 
  of 
  the 
  littoral 
  concrete 
  and 
  in 
  places 
  

   corals 
  above 
  the 
  present 
  tide 
  limits, 
  all 
  point 
  in 
  the 
  same 
  direction, 
  viz., 
  

   to 
  a 
  moderate 
  elevation 
  of 
  the 
  whole 
  country 
  in 
  a 
  recent 
  period, 
  and 
  

   which 
  there 
  are 
  no 
  grounds 
  for 
  supposing 
  to 
  have 
  yet 
  ceased. 
  

  

  (b). 
  Sands 
  and 
  gravels. 
  — 
  The 
  older 
  alluvial 
  clay 
  just 
  described, 
  rests 
  

   in 
  Pegu 
  on 
  a 
  considerable 
  deposit 
  or 
  bottom 
  bed, 
  as 
  it 
  may 
  be 
  considered, 
  

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