﻿176 
  Adams, 
  JBarlow 
  and 
  Ells 
  — 
  Canadian 
  Laurentian. 
  

  

  The 
  northwestern 
  half 
  of 
  the 
  more 
  restricted 
  area 
  at 
  present 
  

   under 
  consideration 
  is 
  underlain 
  by 
  Fundamental 
  Gneiss, 
  pre- 
  

   senting 
  the 
  characters 
  described 
  above. 
  A 
  smaller 
  area 
  of 
  the 
  

   same 
  gneiss 
  occurs 
  at 
  the 
  southwestern 
  corner 
  of 
  the 
  area, 
  in 
  

   the 
  townships 
  of 
  Lutterworth, 
  Snowdon 
  and 
  Glamorgan, 
  while 
  

   in 
  the 
  southern 
  and 
  southeastern 
  portions 
  of 
  the 
  area 
  there 
  are 
  

   other 
  occurrences, 
  which, 
  however, 
  present 
  a 
  more 
  normally 
  

   granitic 
  character. 
  

  

  The 
  southeastern 
  portion 
  of 
  the 
  area 
  is 
  underlain 
  by 
  rocks 
  of 
  

   the 
  so-called 
  Hastings 
  Series, 
  consisting 
  chiefly 
  of 
  thinly-bedded 
  

   limestones, 
  dolomites, 
  etc., 
  cut 
  through 
  by 
  great 
  intrusions 
  of 
  

   gabbro-diorite 
  and 
  granite. 
  These 
  limestones 
  and 
  dolomites 
  

   are 
  usually 
  flne-grained 
  and 
  bluish 
  or 
  greyish 
  in 
  color, 
  with 
  thin 
  

   interstratitied 
  layers, 
  holding 
  sheaf-like 
  bundles 
  of 
  hornblende 
  

   crystals. 
  As 
  compared 
  with 
  the 
  limestones 
  of 
  the 
  Grenville 
  

   series 
  they 
  are 
  comparatively 
  unaltered. 
  They 
  form 
  beyond 
  all 
  

   doubt 
  a 
  true 
  sedimentary 
  series, 
  and 
  in 
  the 
  southeastern 
  corner 
  

   of 
  the 
  area 
  are 
  associated 
  with 
  conglomerates 
  or 
  breccias 
  of 
  

   undoubtedly 
  clastic 
  origin. 
  Between 
  the 
  great 
  area 
  of 
  Funda- 
  

   mental 
  Gneiss 
  in 
  the 
  northwest, 
  and 
  the 
  Hastings 
  series 
  in 
  the 
  

   southeast 
  of 
  the 
  sheet, 
  there 
  lies 
  an 
  irregular-shaped 
  belt 
  of 
  

   rocks, 
  presenting 
  the 
  characters 
  of 
  the 
  typical 
  Grenville 
  series 
  

   as 
  above 
  described, 
  the 
  limestones 
  having 
  in 
  all 
  cases 
  the 
  form 
  

   of 
  coarsely 
  crystalline, 
  white 
  or 
  pinkish 
  marbles, 
  although 
  

   more 
  or 
  less 
  impure. 
  The 
  strike 
  of 
  the 
  foliation 
  of 
  the 
  Gren- 
  

   ville 
  series 
  follows 
  in 
  a 
  general 
  way 
  the 
  boundaries 
  of 
  the 
  

   Fundamental 
  Gneiss, 
  and 
  is 
  seen 
  in 
  an 
  especially 
  distinct 
  man- 
  

   ner 
  to 
  wrap 
  itself 
  around 
  the 
  long 
  and 
  narrow 
  development 
  of 
  

   the 
  gneiss 
  exposed 
  in 
  the 
  southwest 
  corner 
  of 
  the 
  area. 
  Iso- 
  

   lated 
  masses 
  of 
  the 
  limestone 
  and 
  gneiss 
  characteristic 
  of 
  the 
  

   Grenville 
  series 
  are 
  also 
  found 
  in 
  the 
  form 
  of 
  outlying 
  patches 
  

   about 
  its 
  margin, 
  as 
  for 
  instance 
  in 
  the 
  townships 
  of 
  Lutter- 
  

   worth 
  and 
  Stanhope. 
  The 
  relations 
  of 
  the 
  Grenville 
  series 
  to 
  

   the 
  Fundamental 
  gneiss 
  are 
  such 
  as 
  to 
  suggest 
  that 
  in 
  the 
  for- 
  

   mer 
  we 
  have 
  a 
  sedimentary 
  series 
  later 
  in 
  date 
  than 
  the 
  Funda- 
  

   mental 
  Gneiss, 
  which 
  has 
  sunk 
  down 
  into 
  and 
  been 
  invaded 
  by 
  

   intrusions 
  of 
  the 
  latter 
  series 
  when 
  this 
  was 
  in 
  a 
  semi-molten 
  or 
  

   plastic 
  condition. 
  The 
  limestones, 
  while 
  themselves 
  rendered 
  

   more 
  or 
  less 
  plastic 
  by 
  the 
  same 
  heat 
  which 
  softened 
  the 
  lower 
  

   gneisses, 
  do 
  not 
  show 
  any 
  distinct 
  evidence 
  of 
  absorption 
  or 
  

   solution 
  by 
  the 
  invading 
  rocks, 
  unless 
  some 
  of 
  the 
  highly 
  gar- 
  

   netiferous 
  gneisses 
  usually 
  associated 
  with 
  the 
  limestones 
  are 
  

   formed 
  by 
  a 
  commingling 
  of 
  the 
  two 
  rocks. 
  Masses 
  of 
  the 
  

   highly 
  crystalline 
  limestone 
  or 
  marble 
  in 
  some 
  cases 
  lie 
  quite 
  

   isolated 
  in 
  what 
  are, 
  to 
  all 
  appearances, 
  the 
  lower 
  gneisses, 
  as 
  

   if 
  they 
  had 
  been 
  separated 
  from 
  the 
  parent 
  mass, 
  and 
  had 
  

   passed 
  outward 
  or 
  downward 
  into 
  the 
  gneissic 
  magma. 
  

  

  The 
  contact 
  of 
  the 
  Fundamental 
  Gneiss 
  and 
  the 
  Grenville 
  

   series 
  would 
  appear 
  therefore 
  to 
  be 
  a 
  contact 
  of 
  intrusion, 
  in 
  

   very 
  many 
  cases 
  at 
  least. 
  

  

  