﻿Yol. 
  53.] 
  SUDBURY 
  NICKEL 
  DISTEICT 
  ( 
  CANADA). 
  47 
  

  

  granite, 
  which 
  cannot 
  be 
  genetically 
  separated 
  from 
  the 
  green- 
  

   stones. 
  The 
  geological 
  map 
  of 
  the 
  Sudbury 
  district 
  published 
  by 
  

   the 
  Canadian 
  Geological 
  Survey 
  contains 
  nearly 
  one 
  hundred 
  areas 
  

   of 
  greenstone. 
  We 
  will 
  confine 
  our 
  attention 
  to 
  a 
  very 
  small 
  

   number 
  of 
  these 
  nickeliferous 
  eruptives. 
  

  

  The 
  nickeliferous 
  rocks 
  are 
  included 
  in 
  or 
  adjoining 
  the 
  Huronian 
  

   belt 
  already 
  described. 
  They 
  commonly 
  form 
  long 
  elliptical 
  areas 
  

   whose 
  longer 
  axis 
  is 
  more 
  or 
  less 
  parallel 
  to 
  the 
  stratification 
  of 
  the 
  

   Huronian 
  rocks. 
  The 
  largest 
  of 
  these 
  areas 
  extends 
  from 
  the 
  town- 
  

   ship 
  of 
  Garson 
  south-westward 
  into 
  the 
  township 
  of 
  Creighton, 
  

   having 
  a 
  width 
  of 
  nearly 
  4 
  and 
  a 
  length 
  of 
  at 
  least 
  25 
  miles. 
  It 
  

   is 
  crossed 
  by 
  the 
  Canadian 
  Pacific 
  Railway 
  between 
  Murray 
  and 
  

   Rayside 
  Stations. 
  The 
  area 
  second 
  in 
  size 
  is 
  described 
  by 
  Bell 
  as 
  

   extending 
  from 
  the 
  township 
  of 
  Lavack 
  south-westward 
  to 
  the 
  

   township 
  of 
  Trill. 
  Its 
  length 
  is 
  at 
  least 
  18 
  miles, 
  and 
  its 
  width 
  

   between 
  3 
  and 
  4 
  miles. 
  Onaping 
  Station 
  is 
  situated 
  near 
  the 
  south- 
  

   eastern 
  border 
  of 
  this 
  eruptive 
  area. 
  As 
  the 
  former 
  eruptive 
  is 
  well 
  

   exposed 
  in 
  the 
  vicinity 
  of 
  Whitson 
  Lake, 
  it 
  will 
  be 
  convenient 
  to 
  

   refer 
  to 
  it 
  as 
  the 
  Whitson 
  Lake 
  eruptive. 
  For 
  a 
  similar 
  reason, 
  

   the 
  second 
  eruptive 
  area 
  will 
  be 
  referred 
  to 
  as 
  the 
  Windy 
  Lake, 
  

   eruptive. 
  

  

  (ii) 
  The 
  Whitson 
  Lake 
  Eruptive. 
  

  

  The 
  length 
  of 
  this 
  area 
  has 
  been 
  very 
  moderately 
  stated 
  above 
  - 
  r 
  

   there 
  is 
  good 
  reason 
  for 
  regarding 
  it 
  as 
  much 
  greater, 
  and 
  possibly 
  

   connected 
  with 
  other 
  nickeliferons 
  areas 
  which 
  are 
  . 
  now 
  mapped 
  as 
  

   separate 
  eruptives. 
  The 
  best 
  exposures 
  are 
  to 
  be 
  found 
  along 
  the 
  

   shores 
  of 
  the 
  lakes 
  lying 
  within 
  its 
  bounds, 
  and 
  in 
  the 
  cuttings 
  

   of 
  the 
  Canadian 
  Pacific 
  Railway. 
  Along 
  its 
  north-western 
  boundary 
  

   it 
  is 
  flanked 
  by 
  the 
  volcanic 
  breccia 
  previously 
  described. 
  It 
  includes 
  

   three 
  parallel 
  areas, 
  which 
  were 
  mapped 
  by 
  Bell 
  as 
  greenstone, 
  

   granite, 
  and 
  Huronian. 
  It 
  will 
  be 
  shown 
  that 
  the 
  rocks 
  which 
  

   constitute 
  these 
  three 
  terranes, 
  though 
  so 
  different 
  in 
  appearance, 
  

   are 
  genetically 
  a 
  unit, 
  that 
  they 
  are 
  eruptive 
  and 
  younger 
  than 
  the 
  

   enclosing 
  rocks, 
  and 
  that 
  in 
  their 
  apparent 
  diversity 
  they 
  may 
  

   rightly 
  be 
  referred 
  to 
  as 
  nickel-bearing 
  rocks. 
  

  

  a. 
  Exposures 
  along 
  the 
  main 
  line 
  of 
  the 
  Canadian 
  

   Pacific 
  Railway. 
  

  

  This 
  eruptive 
  is 
  well 
  exposed 
  in 
  the 
  railway- 
  cutting 
  between 
  

   Murray 
  and 
  Rayside 
  Stations. 
  Its 
  width 
  here 
  is 
  about 
  4 
  miles. 
  As- 
  

   the 
  rock 
  is 
  freshest 
  towards 
  the 
  centre 
  of 
  the 
  area, 
  it 
  will 
  be 
  ad- 
  

   visable 
  to 
  consider 
  in 
  detail 
  specimens 
  collected 
  there 
  ; 
  then 
  to 
  study 
  

   in 
  order 
  the 
  specimens 
  collected 
  between 
  the 
  fresh 
  central 
  or 
  type- 
  

   rock 
  and 
  the 
  Murray 
  Mines 
  contact, 
  and 
  finally 
  the 
  specimens 
  from 
  

   the 
  north-western 
  half, 
  beginning 
  at 
  the 
  centre, 
  and 
  proceeding 
  

   towards 
  the 
  north-western 
  contact 
  near 
  Rayside 
  Station. 
  

  

  The 
  Type-rock. 
  — 
  About 
  1J 
  mile 
  north-west 
  of 
  Murray 
  Mines, 
  

  

  