﻿4 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  series 
  for 
  the 
  larger, 
  and 
  group 
  for 
  the 
  smaller 
  division 
  ; 
  but 
  it 
  was 
  

   not 
  a 
  matter 
  of 
  great 
  importance. 
  

  

  In 
  the 
  course 
  of 
  the 
  discussion, 
  various 
  speakers 
  pointed 
  out, 
  by 
  way 
  

   of 
  illustration, 
  what 
  they 
  would 
  include 
  under 
  these 
  different 
  heads 
  ; 
  

   and 
  it 
  was 
  clear 
  that 
  there 
  was 
  very 
  much 
  to 
  be 
  done 
  before 
  any 
  

   equivalent 
  value 
  could 
  be 
  attached 
  to 
  the 
  subdivisions 
  of 
  different 
  

   ages, 
  or 
  of 
  the 
  same 
  general 
  age, 
  in 
  widely 
  separated 
  areas. 
  

  

  The 
  English 
  Committee 
  had 
  commenced 
  work 
  upon 
  this 
  question, 
  

   and 
  he 
  had 
  laid 
  before 
  the 
  Congress 
  the 
  Reports 
  of 
  the 
  Subcom- 
  

   mittees 
  which 
  had 
  furnished 
  him 
  with 
  the 
  results 
  of 
  their 
  inquiries, 
  

   as 
  well 
  as 
  some 
  special 
  Reports 
  forwarded 
  to 
  him 
  by 
  individuals. 
  

   The 
  Congress 
  did 
  not, 
  however, 
  pass 
  on 
  to 
  the 
  discussion 
  of 
  these 
  

   matters 
  ; 
  but 
  the 
  manner 
  in 
  which 
  the 
  English 
  Committee 
  were 
  

   organizing 
  their 
  work 
  met 
  with 
  the 
  approval 
  of 
  the 
  Congress, 
  and 
  

   a 
  vote 
  was 
  passed 
  that 
  the 
  other 
  countries 
  should 
  adopt 
  a 
  similar 
  

   plan, 
  and 
  form 
  subcommittees 
  for 
  the 
  investigation 
  of 
  the 
  several 
  

   groups. 
  He 
  was 
  further 
  unofficially 
  requested 
  to 
  get 
  the 
  Reports 
  

   printed 
  as 
  soon 
  as 
  possible, 
  in 
  order 
  to 
  facilitate 
  discussion, 
  and 
  with 
  

   a 
  view 
  to 
  arriving 
  at 
  an 
  understanding 
  upon 
  the 
  simpler 
  questions 
  

   before 
  the 
  next 
  Meeting 
  of 
  the 
  Congress. 
  This 
  was 
  appointed 
  to 
  be 
  

   held 
  at 
  Berlin 
  in 
  1884. 
  The 
  following 
  Congress 
  will 
  be 
  held 
  in 
  

   England. 
  

  

  Dr. 
  T. 
  Stekrt 
  Hunt 
  gave 
  some 
  account 
  of 
  the 
  pre-Cambrian 
  or 
  

   Eozoic 
  rocks 
  of 
  Europo 
  as 
  compared 
  with 
  those 
  of 
  North 
  America. 
  He 
  

   had 
  on 
  several 
  occasions 
  studied 
  the 
  former, 
  both 
  on 
  the 
  continent 
  

   and 
  in 
  the 
  British 
  Isles, 
  especially 
  with 
  Dr. 
  Hicks 
  in 
  Wales 
  in 
  1878. 
  

   In 
  North 
  America 
  the 
  recognized 
  base 
  is 
  a 
  highly 
  granitoid 
  gneiss, 
  

   without 
  observed 
  limestones, 
  which 
  he 
  has 
  called 
  the 
  Ottawa 
  gneiss, 
  

   overlain, 
  probably 
  unconformably, 
  by 
  the 
  Grenville 
  series 
  of 
  Logan, 
  

   consisting 
  chiefly 
  of 
  granitoid 
  gneisses, 
  with 
  crystalline 
  limestones 
  

   and 
  quartzites. 
  These 
  two 
  divisions 
  made 
  up 
  the 
  Laurentian 
  of 
  

   Canada, 
  and 
  correspond 
  respectively 
  to 
  the 
  Lewisian 
  and 
  the 
  Dime- 
  

   tian 
  of 
  Hicks. 
  Resting 
  in 
  discordance 
  on 
  the 
  Laurentian 
  we 
  find 
  

   areas 
  of 
  the 
  jNorian 
  or 
  Labrador 
  series 
  (Upper 
  Laurentian 
  of 
  Logan), 
  

   chiefly 
  made 
  up 
  of 
  anortholite 
  rocks, 
  granitoid 
  or 
  gneissoid 
  in 
  tex- 
  

   ture, 
  with 
  some 
  true 
  gneisses. 
  The 
  Huronian 
  is 
  seen 
  to 
  rest 
  uncon- 
  

   formably 
  on 
  the 
  Laurentian, 
  fragments 
  of 
  which 
  abound 
  in 
  the 
  

   Huronian 
  conglomerates. 
  To 
  the 
  lower 
  portion 
  of 
  the 
  Huronian 
  

   the 
  speaker 
  had 
  formerly 
  referred 
  a 
  great 
  series 
  of 
  petrosilex 
  or 
  

   hallerlinta 
  rocks, 
  described 
  as 
  inchoate 
  gneisses, 
  passing 
  into 
  petro- 
  

   silex-porphyries, 
  occasionally 
  interstratifled 
  with 
  quartzites. 
  This 
  

   series, 
  in 
  many 
  places 
  wanting 
  both 
  in 
  Europe 
  and 
  America, 
  he 
  is 
  

   now 
  satisfied 
  forms 
  an 
  underlying 
  unconformable 
  group— 
  the 
  Arvo- 
  

   nian 
  of 
  Hicks. 
  Above 
  the 
  Huronian 
  is 
  the 
  great 
  Montalban 
  series, 
  

   consisting 
  of 
  grey 
  tender 
  gneisses 
  and 
  quartzose-schists, 
  both 
  

   abounding 
  in 
  muscovite, 
  occasionally 
  with 
  hornblendic 
  rocks. 
  The 
  

   Pebidian 
  of 
  Hicks 
  includes 
  both 
  the 
  Huronian 
  and 
  the 
  Montalban 
  ; 
  

   to 
  which 
  latter 
  belong, 
  according 
  to 
  the 
  speaker, 
  certain 
  gneisses 
  

   and 
  mica-schists 
  both 
  in 
  Scotland 
  and 
  in 
  Ireland, 
  as 
  he 
  had 
  manv 
  

  

  