﻿^>0 
  MR. 
  T. 
  L. 
  WALKER 
  ON 
  THE 
  [Feb. 
  1 
  897, 
  

  

  greenstone 
  ; 
  garnet 
  and 
  biotite 
  are 
  the 
  chief 
  new 
  minerals, 
  while 
  

   the 
  whole 
  rock 
  has 
  been 
  rendered 
  quite 
  crystalline. 
  

  

  Copper 
  Cliff 
  Mine 
  is 
  also 
  situated 
  on 
  a 
  very 
  narrow 
  eruptive 
  stock. 
  

   The 
  greenstone 
  is 
  so 
  much 
  altered 
  that 
  its 
  original 
  nature 
  is 
  quite 
  

   concealed. 
  The 
  microscope 
  shows 
  that 
  uralite, 
  a 
  little 
  secondary 
  

   hornblende, 
  plagioclase, 
  free 
  quartz, 
  and 
  a 
  little 
  micropegmatite 
  are 
  

   'the 
  chief 
  constituents. 
  This 
  rock 
  is 
  thus 
  seen 
  to 
  be 
  much 
  more 
  acid 
  

   than 
  that 
  examined 
  at 
  any 
  of 
  the 
  other 
  nickel 
  mines. 
  

  

  Worthington 
  Mine 
  is 
  connected 
  with 
  an 
  eruptive 
  which 
  is 
  not 
  

   more 
  than 
  50 
  yards 
  wide 
  where 
  the 
  ' 
  Soo 
  ' 
  branch 
  of 
  the 
  Canadian 
  

   Pacific 
  Railway 
  crosses 
  it 
  at 
  Worthington 
  Station. 
  The 
  rock 
  is 
  very 
  

   schistose, 
  and 
  greenish-grey 
  in 
  colour. 
  Some 
  of 
  the 
  fresher 
  specimens 
  

   might 
  be 
  called 
  actinolite-schist, 
  while 
  others 
  are 
  largely 
  changed 
  to 
  

   a 
  fine 
  aggregate 
  of 
  talc, 
  which 
  contains 
  only 
  a 
  few 
  slender 
  actinolite- 
  

   crystals. 
  Pyrrhotite-grains 
  are 
  richly 
  scattered 
  through 
  the 
  rock. 
  

  

  There 
  are 
  a 
  few 
  areas 
  of 
  hornblende-schist 
  in 
  the 
  Sudbury 
  district, 
  

   but 
  it 
  is 
  difficult 
  to 
  determine 
  whether 
  they 
  should 
  be 
  regarded 
  as 
  

   crystalline 
  schists 
  and 
  proper 
  members 
  of 
  the 
  Huronian, 
  or 
  as 
  altered 
  

   greenstones. 
  One 
  of 
  the 
  largest 
  and 
  most 
  accessible 
  of 
  these 
  areas 
  

   is 
  cut 
  by 
  the 
  main 
  line 
  of 
  the 
  Canadian 
  Pacific 
  Railway, 
  about 
  

   3 
  miles 
  west 
  of 
  Sudbury. 
  The 
  rock 
  is 
  rather 
  compact, 
  distinctly 
  

   schistose, 
  and 
  nearly 
  black 
  in 
  colour. 
  The 
  microscope 
  shows 
  that 
  

   it 
  is 
  composed 
  of 
  long, 
  slender 
  crystals 
  of 
  bluish-green 
  hornblende, 
  

   a 
  smaller 
  quantity 
  of 
  quartz 
  and 
  water-clear 
  grains 
  of 
  felspar. 
  

  

  Narrowly 
  elliptical 
  quartz-grains 
  form 
  parallel 
  chains 
  of 
  inclusions 
  

   in 
  the 
  hornblende-crystals. 
  These 
  inclusions 
  occupy 
  a 
  definite 
  plane, 
  

   which, 
  from 
  the 
  following 
  observations, 
  appears 
  to 
  be 
  the 
  positive 
  

   orthodome 
  -f-Poo 
  . 
  (The 
  face 
  usually 
  marked 
  p 
  is 
  here 
  taken 
  to 
  be 
  

   the 
  basis 
  oP) 
  : 
  — 
  

  

  (i) 
  In 
  sections 
  of 
  hornblende-individuals 
  the 
  inclusion-chains 
  

   are 
  at 
  right 
  angles 
  to 
  the 
  cleavage 
  — 
  hence 
  they 
  lie 
  in 
  a 
  

   plane 
  of 
  the 
  orthodiagonal 
  zone, 
  

   (ii) 
  The 
  maximum 
  extinction 
  for 
  sections 
  parallel 
  to 
  oo 
  5? 
  oo 
  

   is 
  13° 
  55'. 
  Such 
  sections 
  show 
  that 
  the 
  chains 
  of 
  inclu- 
  

   sions 
  form 
  an 
  angle 
  of 
  75° 
  with 
  the 
  cleavage, 
  and 
  an 
  

  

  angle 
  of 
  89° 
  with 
  the 
  axis 
  of 
  elasticity 
  VY 
  . 
  

  

  (iii) 
  Sections 
  with 
  smaller 
  angles 
  of 
  extinction 
  give 
  larger 
  

   angles 
  between 
  the 
  cleavage 
  and 
  the 
  inclusion-chains. 
  

  

  Similar 
  disjointing 
  of 
  blade-like 
  crystals 
  by 
  pressure 
  is 
  observed 
  in 
  

   many 
  minerals, 
  particularly 
  in 
  the 
  piedmontite 
  of 
  Japanese 
  pied- 
  

   montite-sehists. 
  Parting 
  of 
  hornblende-crystals 
  along 
  +P00 
  has 
  

   been 
  observed 
  by 
  Cross 
  in 
  actinolite-schists 
  from 
  Britanny, 
  and 
  also 
  

   less 
  perfectly 
  in 
  green 
  schists 
  from 
  Zermatt 
  in 
  Switzerland. 
  

  

  The 
  same 
  amphibolite-area 
  may 
  be 
  examined 
  about 
  | 
  mile 
  north 
  

   •of 
  Copper 
  CJiff 
  Mine. 
  The 
  nickel-bearing 
  rocks 
  at 
  Stobie 
  Mine 
  

   resemble 
  these 
  amphibolites, 
  and 
  it 
  is 
  possible 
  that 
  they 
  are 
  all 
  

   .connected. 
  

  

  