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  Adams, 
  Ba/rlow 
  and 
  Ells 
  — 
  Canadian 
  Laurentian. 
  

  

  and 
  that 
  the 
  explanation 
  of 
  these 
  relations 
  as 
  given 
  above 
  is 
  

   correct, 
  the 
  Laurentian 
  system 
  of 
  Logan 
  will 
  resolve 
  itself 
  into 
  

   an 
  enormous 
  area 
  of 
  the 
  Fundamental 
  Gneiss, 
  which 
  is 
  essen- 
  

   tially 
  of 
  igneous 
  origin 
  and 
  which 
  there 
  is 
  every 
  reason 
  to 
  

   believe 
  forms 
  part 
  of 
  the 
  downward 
  extension 
  of 
  the 
  original 
  

   crust 
  of 
  our 
  planet, 
  perhaps 
  many 
  times 
  remelted 
  and 
  certainly 
  

   in 
  many 
  places 
  penetrated 
  by 
  enormous 
  intrusions 
  of 
  later 
  date 
  ; 
  

   into 
  which 
  Fundamental 
  Gneiss, 
  when 
  in 
  a 
  softened 
  condition, 
  

   there 
  have 
  sunk 
  portions 
  of 
  an 
  overling 
  series, 
  consisting 
  

   chiefly 
  of 
  limestones. 
  

  

  Farther 
  east, 
  in 
  that 
  portion 
  of 
  the 
  province 
  of 
  Quebec 
  

   where 
  the 
  Grenville 
  series 
  was 
  first 
  studied 
  by 
  Logan, 
  the 
  

   rocks 
  of 
  the 
  Hastings 
  series 
  proper 
  have 
  not 
  been 
  recognized. 
  

   The 
  Lower 
  Paleozoic 
  strata 
  rest 
  directly 
  upon 
  the 
  Grenville 
  

   series 
  and 
  would 
  cover 
  up 
  the 
  Hastings 
  series 
  to 
  the 
  south 
  

   should 
  it 
  extend 
  as 
  far 
  east 
  as 
  this. 
  The 
  limestones 
  of 
  the 
  

   Grenville 
  series, 
  moreover, 
  here 
  extend 
  much 
  farther 
  back 
  

   from 
  the 
  edge 
  of 
  the 
  protaxisin 
  bands 
  and 
  streaks 
  conforming 
  to 
  

   the 
  strike 
  of 
  the 
  underlying 
  gneissic 
  rocks, 
  so 
  that 
  the 
  origin 
  

   of 
  the 
  series 
  and 
  its 
  relations 
  to 
  the 
  Fundamental 
  Gneiss 
  is 
  not 
  

   so 
  clearly 
  indicated. 
  When, 
  however, 
  its 
  relations 
  here 
  are 
  

   interpreted 
  in 
  the 
  light 
  of 
  the 
  Ontario 
  occurrences, 
  there 
  seems 
  

   to 
  be 
  no 
  reason 
  why 
  the 
  same 
  explanation 
  might 
  not 
  be 
  offered 
  

   to 
  account 
  for 
  its 
  origin 
  also. 
  The 
  bands 
  of 
  limestone, 
  which 
  

   often 
  vary 
  in 
  thickness 
  from 
  place 
  to 
  place, 
  and 
  are 
  frequently 
  

   interrupted 
  in 
  their 
  course 
  or 
  abruptly 
  cut 
  off, 
  might 
  be 
  con- 
  

   sidered 
  as 
  having 
  taken 
  their 
  form 
  from 
  long 
  folds 
  in 
  the 
  series 
  

   from 
  which 
  they 
  were 
  derived 
  as 
  it 
  settled 
  down 
  into 
  the 
  

   magma 
  beneath, 
  or 
  as 
  having 
  been 
  separated 
  by 
  great 
  lateral 
  

   intrusions 
  of 
  the 
  gneissic 
  magma. 
  Their 
  original 
  shape 
  and 
  

   character 
  has, 
  however, 
  without 
  doubt 
  been 
  greatly 
  altered 
  by 
  

   the 
  enormous 
  movements 
  to 
  which 
  both 
  series 
  of 
  rocks 
  have 
  

   been 
  subsequently 
  subjected. 
  

  

  If 
  again 
  this 
  proves 
  to 
  be 
  the 
  true 
  explanation 
  of 
  the 
  rela- 
  

   tions 
  of 
  these 
  series, 
  the 
  Grenville 
  series 
  will 
  cease 
  to 
  be 
  an 
  

   anomaly 
  among 
  our 
  Archaean 
  formations 
  and 
  will, 
  so 
  far 
  as 
  its 
  

   mode 
  of 
  occurrence 
  is 
  concerned, 
  bear 
  the 
  same 
  relation 
  to 
  

   the 
  Fundamental 
  Gneiss 
  as 
  the 
  Huronian 
  does 
  farther 
  west 
  in 
  

   the 
  Lake 
  Superior 
  and 
  Huron 
  district, 
  as 
  shown 
  by 
  Lawson 
  

   and 
  Barlow; 
  the 
  similarity 
  in 
  position, 
  however, 
  not 
  imply- 
  

   ing 
  identity 
  in 
  age. 
  

  

  The 
  recognition 
  of 
  the 
  Grenville 
  series 
  as 
  consisting 
  of 
  a 
  

   series 
  of 
  sedimentary 
  rocks, 
  largely 
  limestones, 
  invaded 
  by 
  

   igneous 
  material 
  which 
  now 
  makes 
  up 
  by 
  far 
  the 
  greater 
  por- 
  

   tion 
  of 
  the 
  series 
  and 
  consists 
  largely 
  of 
  extravasations 
  of 
  the 
  

   Fundamental 
  Gneiss, 
  is 
  now 
  pretty 
  certainly 
  established 
  by 
  the 
  

   field 
  evidence. 
  Its 
  recognition 
  as 
  a 
  portion 
  of 
  the 
  Hastings 
  

   series 
  which 
  has 
  been 
  intensely 
  metamorphosed, 
  will 
  probably 
  

   be 
  more 
  clearly 
  established 
  as 
  the 
  field 
  work 
  progresses. 
  Since 
  

   subordinate 
  areas 
  of 
  the 
  Grenville 
  series 
  also 
  occur 
  to 
  the 
  

  

  