﻿NEGKAIS 
  EOCKS. 
  119 
  

  

  as 
  well 
  as 
  to 
  chemical 
  alteration. 
  This 
  latter 
  is 
  displayed 
  in 
  the 
  

   numerous 
  veins 
  of 
  fibrous 
  calcite 
  and 
  fibrous 
  quartz 
  which 
  traverse 
  

   the 
  rock, 
  the 
  former 
  attaining- 
  a 
  thickness 
  of 
  a 
  couple 
  of 
  inches, 
  the 
  

   latter 
  rarely 
  attaining 
  half 
  an 
  inch. 
  Some 
  of 
  the 
  shale 
  where 
  the 
  veins 
  

   are 
  most 
  numerous 
  is 
  of 
  a 
  deep 
  black 
  color 
  and 
  very 
  hard 
  and 
  glossy, 
  and 
  

   I 
  can 
  convey 
  no 
  better 
  idea 
  of 
  the 
  lumps 
  of 
  this 
  rock 
  scattered 
  along" 
  

   the 
  shore 
  than 
  by 
  comparing 
  them 
  to 
  lumps 
  of 
  black 
  putty, 
  which 
  they 
  

   precisely 
  resemble. 
  A 
  little 
  nodular 
  soapstone 
  is 
  also 
  found 
  scattered 
  

   here 
  and 
  there, 
  and 
  the 
  occurrence 
  of 
  this 
  mineral, 
  together 
  with 
  its 
  

   invariable 
  associate, 
  the 
  fibrous 
  vein-quartz, 
  points 
  to 
  this 
  being 
  a 
  focus 
  

   for 
  that 
  peculiar 
  metamorphism 
  which 
  has 
  so 
  generally 
  affected 
  this 
  group. 
  

   These 
  shales 
  constitute 
  the 
  low 
  ridge, 
  which 
  here 
  forms 
  the 
  axis 
  of 
  the 
  

   range, 
  where 
  crossed 
  by 
  the 
  pass 
  leading 
  to 
  Ywot-pa, 
  but 
  on 
  which, 
  

   from 
  its 
  forest-clad 
  nature, 
  little 
  is 
  seen 
  of 
  the 
  rocks 
  passed 
  over. 
  It 
  is 
  

   here 
  that 
  the 
  " 
  mud 
  volcano" 
  of 
  the 
  charts 
  of 
  this 
  coast 
  is 
  situated, 
  a 
  

   complete 
  misnomer, 
  as 
  it 
  has 
  no 
  connection 
  with 
  volcanic 
  action 
  properly 
  

   so 
  called, 
  and 
  neither 
  lava, 
  ashes, 
  nor 
  other 
  volcanic 
  rocks 
  are 
  seen 
  about 
  it. 
  

  

  This 
  " 
  mud 
  volcano" 
  is 
  situated 
  on 
  the 
  hill 
  side, 
  where 
  it 
  rapidly 
  

   slopes 
  down 
  to 
  the 
  shore, 
  and 
  within 
  a 
  stone's 
  throw 
  of 
  the 
  sea. 
  A 
  narrow 
  

   footpath 
  exists 
  along 
  the 
  coast 
  here, 
  on 
  the 
  East 
  of 
  which 
  at 
  one 
  spot 
  a 
  

   small 
  mound 
  of 
  loose 
  pulverulent 
  shale 
  rises 
  a 
  few 
  feet 
  in 
  height, 
  and 
  about 
  

   thirty 
  feet 
  at 
  most 
  in 
  diameter, 
  over 
  which 
  any 
  one 
  might 
  walk 
  without 
  

   having 
  his 
  attention 
  arrested 
  by 
  any 
  peculiarity. 
  This 
  mound 
  is 
  the 
  

   " 
  mud 
  volcano/' 
  A 
  very 
  similar 
  instance 
  is 
  seen 
  near 
  the 
  shore 
  near 
  

   Ngan-khyoung, 
  and 
  my 
  remarks 
  on 
  one 
  will 
  be 
  equally 
  applicable 
  to 
  

   both. 
  This 
  mound 
  consists 
  of 
  a 
  greenish 
  shale, 
  very 
  much 
  comminuted 
  

   and 
  mixed 
  with 
  fragments 
  of 
  veins 
  of 
  calcite, 
  from 
  the 
  thickness 
  of 
  

   cardboard 
  to 
  one 
  or 
  two 
  inches. 
  These 
  fragments 
  have 
  evidently 
  resulted 
  

   from 
  the 
  spontaneous 
  dehiscence 
  of 
  the 
  compact 
  shale 
  they 
  originally 
  tra- 
  

   versed 
  ; 
  and 
  this 
  is 
  seen 
  in 
  the 
  constitution 
  of 
  the 
  thicker 
  veins, 
  which 
  are 
  

   formed 
  by 
  the 
  union 
  and 
  anastomosis 
  of 
  numerous 
  smaller 
  veins, 
  wherein 
  

  

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