﻿PEGU 
  GROUP. 
  85 
  

  

  The 
  channel 
  of 
  the 
  Irrawadi 
  here 
  intervenes, 
  causing 
  a 
  break 
  between 
  

   the 
  section 
  above 
  given 
  and 
  its 
  continuation 
  in 
  the 
  opposite 
  bank. 
  Whilst, 
  

   however, 
  the 
  precise 
  thickness 
  of 
  beds 
  represented 
  by 
  the 
  gap 
  thus 
  caused 
  

   cannot 
  be 
  determined, 
  it 
  is 
  certain 
  that 
  the 
  beds 
  which 
  come 
  next 
  in 
  

   sequence, 
  below 
  the 
  town 
  of 
  Prome, 
  present 
  the 
  same 
  facies 
  as 
  regard 
  

   their 
  fossils 
  as 
  those 
  opposite 
  the 
  town, 
  and 
  that 
  the 
  whole 
  may 
  fairly 
  

   be 
  classed 
  on 
  the 
  evidence 
  of 
  their 
  included 
  fossils, 
  as 
  one 
  group. 
  Con- 
  

   sidering 
  that 
  the 
  present 
  bed 
  of 
  the 
  Irrawadi 
  toward 
  the 
  frontier 
  seems 
  

   to 
  mark 
  a 
  line 
  of 
  weakness, 
  disturbance 
  and 
  crushing, 
  as 
  evinced 
  by 
  

   the 
  condition 
  of 
  the 
  strata 
  at 
  many 
  places 
  in 
  its 
  bed, 
  it 
  is 
  not 
  necessary 
  

   to 
  assume 
  any 
  very 
  high 
  figure 
  as 
  the 
  thickness 
  of 
  the 
  beds 
  represented 
  

   by 
  the 
  gap 
  ; 
  but 
  for 
  any 
  exact 
  estimate 
  there 
  exist 
  no 
  data 
  whatever. 
  

   The 
  most 
  important 
  beds 
  in 
  the 
  section, 
  however, 
  which, 
  I 
  think, 
  must 
  

   intervene 
  at 
  this 
  place, 
  are 
  some 
  very 
  fossiliferous 
  blue 
  shales 
  which 
  in 
  

   the 
  Records 
  (Vol. 
  II, 
  part 
  4, 
  page 
  80,) 
  I 
  have 
  termed 
  Kama 
  clay, 
  from 
  its 
  

   being 
  fairly 
  exhibited 
  on 
  the 
  bank 
  of 
  the 
  Irrawadi 
  under 
  the 
  important 
  

   town 
  of 
  Kama 
  18 
  miles 
  above 
  Prome. 
  They 
  are 
  also 
  seen 
  in 
  many 
  

   spots 
  East 
  of 
  the 
  Irrawadi, 
  and 
  may 
  be 
  generally 
  detected 
  at 
  once 
  by 
  the 
  

   numerous 
  well-preserved 
  fossils 
  they 
  contain, 
  though 
  in 
  other 
  respects 
  

   they 
  much 
  resemble 
  the 
  unfossiliferous 
  Sitsyahn 
  shales 
  at 
  the 
  base 
  of 
  the 
  

   group. 
  Blue 
  shales 
  appear 
  to 
  have 
  been 
  largely 
  formed 
  in 
  these 
  seas 
  

   during 
  the 
  whole 
  of 
  the 
  Tertiary 
  period 
  (without 
  going 
  earlier), 
  as 
  they 
  

   occur 
  largely 
  throughout 
  the 
  Nummulitic 
  group, 
  largely 
  at 
  the 
  base 
  of 
  

   the 
  newer 
  Tertiary 
  group 
  immediately 
  succeeding 
  to 
  the 
  Nummulitic 
  

   limestone, 
  and 
  higher 
  again 
  in 
  the 
  series, 
  in 
  the 
  case 
  of 
  the 
  Kama 
  clay 
  

   in 
  question, 
  which 
  latest 
  extensive 
  development 
  of 
  the 
  shale 
  is 
  far 
  richer 
  

   •than 
  the 
  others 
  in 
  organic 
  remains. 
  The 
  character 
  of 
  the 
  deposit 
  is 
  one 
  

   of 
  deep, 
  still 
  water, 
  favorable 
  to 
  the 
  tranquil 
  accumulation 
  of 
  the 
  finest 
  

   sediment, 
  embedding 
  foraminifera 
  and 
  minute 
  and 
  well-preserved 
  pelecy- 
  

   poda 
  in 
  the 
  positions 
  and 
  attitudes 
  occupied 
  by 
  them 
  during 
  life. 
  The 
  

   number 
  of 
  species, 
  however, 
  is 
  not 
  large, 
  nor 
  are 
  the 
  individuals 
  so 
  

  

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