﻿108 
  THEOBALD 
  : 
  GEOLOGY 
  OF 
  PEGU. 
  

  

  ling. 
  Just 
  below 
  the 
  spot 
  where 
  the 
  above-mentioned 
  small 
  stream 
  

   enters 
  the 
  Irrawadi, 
  the 
  lowest 
  bed 
  seen 
  is 
  exposed 
  on 
  the 
  river 
  bank 
  

   and 
  within 
  a 
  few 
  yards 
  of 
  the 
  Penthaling 
  fault, 
  which 
  is, 
  however, 
  

   quite 
  masked 
  by 
  recent 
  sedimentary 
  deposits. 
  This 
  lowest 
  bed 
  is 
  a 
  

   soft 
  sandstone, 
  dipping 
  70° 
  to 
  South-south-west, 
  or 
  directly 
  away 
  from 
  

   the 
  fault, 
  which 
  strikes 
  nearly 
  West 
  -north-west 
  from 
  the 
  river 
  ; 
  and 
  it 
  

   contains 
  numerous 
  specimens 
  of 
  a 
  coral 
  {flabellum) 
  , 
  also 
  seen 
  abundant- 
  

   ly 
  opposite 
  Prome, 
  and 
  marking 
  a 
  high 
  position 
  in 
  the 
  newer 
  Tertiary 
  

   group. 
  Above 
  this 
  sandstone 
  stratigraphically, 
  there 
  comes 
  in 
  a 
  thick 
  series 
  

   of 
  sands 
  and 
  conglomerates 
  which 
  I 
  am 
  inclined 
  to 
  refer 
  to 
  the 
  lowest 
  

   portion 
  of 
  the 
  fossil-wood 
  group. 
  One 
  of 
  the 
  highest 
  beds 
  seen 
  close 
  

   to 
  the 
  lime-kilns 
  above 
  Penthaling 
  village 
  is 
  a 
  thick 
  bed 
  of 
  conglo- 
  

   merate. 
  This 
  conglomerate 
  is 
  very 
  hard, 
  pebbly, 
  and 
  ferruginous, 
  the 
  in- 
  

   cluded 
  pebbles 
  being 
  covered 
  with 
  a 
  dark 
  glaze. 
  It 
  is 
  almost 
  devoid 
  of 
  

   fossils, 
  but 
  I 
  have 
  detected 
  mammalian 
  bones 
  in 
  it, 
  though 
  such 
  are 
  ex- 
  

   tremely 
  rare. 
  Near 
  Penthaling 
  it 
  dips 
  West-by-south, 
  but 
  as 
  we 
  ap- 
  

   proach 
  the 
  Lime-hill 
  along 
  the 
  river 
  bank, 
  the 
  lower 
  beds 
  veer 
  gra- 
  

   dually 
  round 
  from 
  West-by-south 
  (dip) 
  , 
  through 
  South-west, 
  to 
  South- 
  

   south-west 
  ; 
  which 
  dip 
  would 
  seem 
  to 
  be 
  the 
  result 
  of 
  the 
  mechanical 
  

   intrusion 
  of 
  the 
  mass 
  of 
  the 
  Lime-hill 
  brought 
  up 
  along 
  the 
  previously 
  

   mentioned 
  Penthaling 
  fault. 
  

  

  The 
  Lime-hill 
  proper, 
  or 
  main 
  ridge, 
  is 
  a 
  barn-shaped 
  mass 
  of 
  Num- 
  

   mulitic 
  strata 
  brought 
  up 
  by 
  faults 
  through 
  the 
  newer 
  Tertiary 
  beds 
  

   which 
  form 
  the 
  surrounding 
  country. 
  The 
  hill 
  impinges 
  on 
  the 
  Irra- 
  

   wadi, 
  but 
  the 
  Nummulitics 
  do 
  not 
  come 
  down 
  to 
  the 
  bank, 
  being 
  faulted 
  

   off 
  from 
  it 
  by 
  the 
  interposition 
  of 
  a 
  narrow 
  band 
  of 
  the 
  sandstones 
  

   of 
  the 
  newer 
  group. 
  On 
  the 
  summit 
  of 
  the 
  hill, 
  Nummulitic 
  limestone 
  

   occurs 
  in 
  situ 
  in 
  sundry 
  spots, 
  and 
  on 
  its 
  southern 
  slopes 
  either 
  in 
  situ 
  

   or 
  in 
  masses 
  undergoing 
  removal 
  by 
  ordinary 
  denudation. 
  Standing 
  

   near 
  the 
  river 
  at 
  the 
  mouth 
  of 
  the 
  small 
  valley 
  which 
  intervenes 
  between 
  

   this 
  and 
  the 
  Penthaling 
  ridge, 
  an 
  enormous 
  block 
  of 
  this 
  limestone 
  is 
  

  

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