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  THEOBALD: 
  GEOLOGY 
  OF 
  PEGU. 
  

  

  XIV. 
  — 
  Intensive 
  Rocks. 
  

   Under 
  the 
  head 
  of 
  l 
  intrusive 
  rocks', 
  serpentine 
  is 
  the 
  only 
  one 
  which 
  

   anywhere 
  attains 
  any 
  considerable 
  development 
  in 
  Pegu; 
  and 
  with 
  it 
  

   I 
  shall 
  consider 
  the 
  curious 
  steatite 
  veins 
  of 
  the 
  Arakan 
  range, 
  not 
  

   because 
  they 
  are 
  themselves 
  of 
  intrusive 
  origin, 
  but 
  because 
  it 
  seems 
  not 
  

   improbable 
  that 
  they 
  may 
  be 
  the 
  result 
  of 
  those 
  forces 
  chemical 
  or 
  

   metamorphic 
  which 
  attended, 
  whether 
  as 
  cause 
  or 
  effect, 
  the 
  intrusion 
  

   of 
  serpentine 
  among 
  the 
  rocks 
  of 
  the 
  Arakan 
  raDge. 
  

  

  The 
  occurrence 
  of 
  a 
  bedded 
  trappean 
  rock 
  has 
  already 
  been 
  noticed 
  

   among 
  the 
  Miocene 
  rocks 
  of 
  Eastern 
  Prome, 
  but 
  being 
  a 
  regularly 
  

   intercalated 
  member 
  of 
  that 
  group, 
  I 
  shall 
  not 
  farther 
  advert 
  to 
  it 
  here. 
  

  

  Trachyte. 
  — 
  About 
  four 
  miles, 
  or 
  rather 
  less, 
  East-by-north 
  from 
  the 
  

   small 
  village 
  of 
  Byangyee 
  on 
  the 
  Bassein 
  river, 
  some 
  fourteen 
  miles 
  South 
  

   of 
  Ngaputau, 
  occurs 
  a 
  large 
  mass 
  of 
  rock 
  known 
  to 
  the 
  Burmese 
  of 
  the 
  

   neighbourhood 
  by 
  the 
  name 
  of 
  ' 
  Chouk-talon/ 
  or 
  ' 
  the 
  single 
  stone/ 
  

   which 
  marks 
  the 
  site 
  of 
  a 
  hidden 
  treasure, 
  according 
  to 
  these 
  imagi- 
  

   native 
  and 
  credulous 
  people. 
  This 
  rock, 
  which 
  has 
  the 
  appearance 
  of 
  

   a 
  very 
  irregularly 
  shaped 
  and 
  imperfectly 
  rounded 
  boulder, 
  of 
  hardly 
  less 
  

   than 
  6 
  feet 
  in 
  its 
  greatest 
  diameter, 
  consists 
  of 
  a 
  greenish 
  purplish 
  tra- 
  

   chyte 
  weathering 
  to 
  a 
  dark 
  brown 
  color, 
  and 
  containing 
  small 
  crystals 
  of 
  

   glassy 
  felspar 
  and 
  olivine. 
  Considering 
  the 
  dimensions 
  of 
  this 
  rock, 
  and 
  

   that 
  nothing 
  like 
  it 
  is 
  anywhere 
  known 
  in 
  the 
  province, 
  one 
  would 
  be, 
  

   in 
  a 
  more 
  Northerly 
  latitude, 
  tempted 
  to 
  regard 
  it 
  as 
  an 
  erratic, 
  though 
  

   in 
  that 
  case 
  we 
  should 
  undoubtedly 
  be 
  led 
  to 
  expect 
  some 
  other 
  compa- 
  

   nion 
  blocks 
  likewise; 
  but 
  this 
  explanation 
  will 
  clearly 
  not 
  serve 
  here. 
  

   This 
  ' 
  Chouk-talon' 
  fragment 
  is 
  exposed 
  in 
  the 
  bed 
  of 
  a 
  small 
  stream, 
  

   the 
  only 
  rocks 
  seen 
  in 
  which 
  are 
  the 
  unaltered 
  shales 
  and 
  sandstones 
  

   of 
  the 
  uppermost 
  division 
  of 
  the 
  Nummulitic 
  group. 
  These 
  beds 
  are 
  

   seen 
  dipping 
  at 
  low 
  angles 
  in 
  close 
  proximity 
  to 
  the 
  block 
  of 
  trachyte 
  

   and 
  seemingly 
  unaltered, 
  or 
  not 
  very 
  appreciably 
  so. 
  What 
  the 
  trachyte 
  

   rests 
  on 
  is 
  not 
  seen, 
  owing 
  to 
  its 
  base 
  being 
  surrounded 
  with 
  the 
  

  

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