﻿Intrusive 
  rocks. 
  147 
  

  

  which 
  are 
  here 
  seen 
  in 
  contact 
  with 
  that 
  rock. 
  At 
  Nattoung, 
  Axial 
  

   beds 
  are 
  passed 
  over, 
  which 
  are 
  probably 
  lower 
  in 
  the 
  series 
  than 
  those 
  

   to 
  the 
  North, 
  and 
  are 
  continued 
  some 
  distance 
  up 
  the 
  base 
  of 
  the 
  hill 
  

   when 
  serpentine 
  comes 
  in 
  and 
  forms 
  the 
  entire 
  summit. 
  Viewed 
  from 
  

   a 
  distance, 
  Nattoung 
  seems 
  an 
  ordinary 
  conical-shaped 
  hill, 
  with 
  nothing 
  

   particular 
  to 
  distinguish 
  it, 
  but 
  it 
  is 
  in 
  reality 
  inaccessibly 
  scarped 
  on 
  

   three 
  sides 
  and 
  can 
  only 
  be 
  ascended 
  on 
  one 
  side 
  by 
  a 
  most 
  precipitous 
  

   path. 
  It 
  is 
  certain, 
  however, 
  that 
  it 
  marks 
  the 
  termination 
  of 
  the 
  

   serpentine 
  to 
  the 
  South, 
  as 
  no 
  fragments 
  of 
  that 
  rock 
  find 
  their 
  way 
  

   into 
  the 
  Thanni 
  stream 
  which 
  flows 
  but 
  a 
  little 
  to 
  the 
  South. 
  In 
  the 
  

   Thanni 
  stream 
  and 
  on 
  the 
  road 
  South 
  from 
  Alaydoung 
  village, 
  which 
  

   runs 
  over 
  Nummulitic 
  rocks 
  a 
  little 
  way 
  out 
  from 
  the 
  Axial 
  boundary, 
  

   no 
  alteration 
  whatever 
  is 
  perceptible 
  in 
  the 
  newer 
  groups, 
  though 
  they 
  

   have 
  undergone 
  much 
  disturbance 
  and 
  mechanical 
  violence. 
  A 
  few 
  

   miles 
  South 
  of 
  Nattoung 
  and 
  about 
  two 
  miles 
  West 
  of 
  Laidi 
  on 
  the 
  Thanni 
  

   stream 
  occur 
  the 
  two 
  small 
  hills 
  of 
  Thytsi-doung 
  and 
  Hnor-doung.* 
  

   These 
  are 
  both 
  small 
  peaks 
  of 
  serpentine 
  capping 
  altered 
  strata, 
  which 
  

   I 
  formerly 
  regarded 
  as 
  belonging 
  to 
  the 
  Axial 
  group, 
  but 
  which 
  are 
  now 
  

   included 
  in 
  the 
  Negrais 
  group. 
  

  

  These 
  patches 
  are 
  insignificant 
  in 
  extent 
  and 
  separated 
  by 
  altered 
  

   rocks, 
  but 
  midway 
  between 
  these 
  a 
  very 
  small 
  patch 
  of 
  serpentine 
  

   occurs 
  a 
  few 
  yards 
  only 
  in 
  diameter. 
  Thytsidoung 
  is 
  the 
  last 
  of 
  the 
  

   more 
  considerable 
  outbursts 
  of 
  serpentine 
  at 
  this 
  locality 
  ; 
  but 
  a 
  little 
  

   further 
  south, 
  a 
  little 
  serpentine 
  is 
  seen 
  on 
  one 
  of 
  the 
  low 
  hills 
  North 
  

   of 
  the 
  Booyoo 
  stream, 
  but 
  its 
  extent 
  is 
  very 
  limited. 
  It 
  is 
  very 
  probably 
  

  

  * 
  Near 
  this 
  hill 
  my 
  colleague 
  Mr. 
  Fedden 
  has 
  noticed 
  a 
  little 
  " 
  Trap." 
  After 
  examining 
  

   the 
  spot, 
  however, 
  I 
  felt 
  unwilling 
  to 
  consider 
  the 
  rock 
  as 
  distinct 
  from 
  those 
  around 
  it, 
  

   though 
  I 
  was 
  in 
  doubt 
  whether 
  to 
  regard 
  it 
  as 
  connected 
  with 
  the 
  serpentine, 
  or 
  with 
  the 
  

   altered 
  Negrais 
  group, 
  and 
  the 
  result 
  of 
  the 
  close 
  proximity 
  of 
  the 
  serpentine 
  to 
  some 
  of 
  the 
  

   more 
  homogeneous 
  shales 
  of 
  that 
  age. 
  It 
  has 
  much 
  the 
  appearance 
  of 
  a 
  trap, 
  but 
  there 
  

   is 
  little 
  of 
  it 
  seen, 
  and 
  hearing 
  in 
  mind 
  the 
  massive 
  potstone-like 
  aspect 
  assumed 
  hy 
  

   some 
  shale 
  heds 
  along 
  the 
  serpentine 
  junction, 
  I 
  am 
  inclined 
  to 
  regard 
  it 
  rather 
  as 
  a 
  

   product 
  of 
  metamorphism, 
  resulting 
  from 
  the 
  serpentine, 
  than 
  as 
  a 
  properly 
  intrusive 
  trap. 
  

  

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