﻿60 
  PKOCEEDTNGS 
  OP 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  Post-Secondary 
  rocks, 
  and 
  the 
  third 
  was 
  a 
  fresh 
  subject 
  of 
  dis- 
  

   cussion 
  — 
  the 
  origin 
  and 
  history 
  of 
  the 
  crystalline 
  schists 
  — 
  brought 
  

   forward 
  by 
  the 
  Organizing 
  Committee 
  and 
  treated 
  in 
  a 
  novel 
  manner, 
  

   by 
  obtaining 
  and 
  printing 
  beforehand 
  dissertations 
  from 
  several 
  

   specialists. 
  On 
  none 
  of 
  the 
  subjects 
  named 
  was 
  there 
  any 
  attempt 
  

   to 
  arrive 
  at 
  a 
  decision 
  : 
  there 
  was 
  simply 
  a 
  discussion. 
  It 
  may 
  be 
  

   added 
  that, 
  whereas 
  in 
  one 
  of 
  the 
  stratigraphical 
  questions 
  — 
  the 
  

   Cambrian 
  and 
  Silurian 
  — 
  there 
  was 
  some 
  approach 
  to 
  a 
  general 
  

   agreement 
  about 
  the 
  principal 
  facts, 
  and 
  in 
  the 
  other 
  a 
  majority 
  of 
  

   the 
  speakers 
  were 
  in 
  favour 
  of 
  a 
  particular 
  view, 
  the 
  subject 
  of 
  the 
  

   crystalline 
  schists 
  was 
  left 
  as 
  chaotic 
  as 
  ever, 
  or 
  as, 
  according 
  to 
  

   some 
  of 
  the 
  disputants, 
  were 
  the 
  conditions 
  of 
  the 
  geological 
  era 
  

   when 
  the 
  schists 
  themselves 
  were 
  formed. 
  So 
  far 
  the 
  discussion 
  has 
  

   scarcely 
  tended 
  towards 
  unification 
  of 
  either 
  nomenclature 
  or 
  views 
  ; 
  

   the 
  Neoneptunists 
  still 
  stand 
  widely 
  apart 
  from 
  the 
  Neoplutonists 
  ; 
  

   nor 
  does 
  there 
  appear 
  to 
  be 
  any 
  prospect 
  of 
  agreement 
  between 
  those 
  

   who 
  pin 
  their 
  faith 
  on 
  gradual 
  chemical 
  or 
  hydrothermic 
  action 
  and 
  

   those 
  who 
  believe 
  in 
  violent 
  movements 
  of 
  the 
  earth's 
  crust, 
  or 
  

   between 
  those 
  who 
  contend 
  that 
  the 
  ' 
  Urgneiss 
  ' 
  could 
  only 
  have 
  

   been 
  deposited 
  in 
  the 
  Archaean 
  era 
  and 
  in 
  the 
  depths 
  of 
  the 
  

   primaeval 
  ocean, 
  and 
  those 
  who 
  urge 
  that 
  gneiss 
  absolutely 
  undis- 
  

   tinguishable 
  from 
  its 
  pre-Cambrian 
  type 
  has 
  been 
  formed 
  in 
  all 
  

   geological 
  epochs, 
  and 
  may 
  be 
  forming 
  at 
  the 
  present 
  day 
  under 
  

   favourable 
  circumstances 
  of 
  heat 
  and 
  pressure. 
  

  

  The 
  discussion 
  on 
  Tertiary 
  classification, 
  too, 
  was 
  almost 
  confined 
  

   to 
  one 
  point 
  — 
  the 
  distinction 
  of 
  the 
  Quaternary 
  as 
  an 
  era 
  apart 
  from 
  

   the 
  Tertiary. 
  The 
  important 
  question 
  as 
  to 
  whether 
  some 
  better 
  

   classification 
  could 
  not 
  be 
  adopted 
  than 
  that 
  into 
  Eocene, 
  Oligocene, 
  

   Miocene, 
  and 
  Pliocene, 
  the 
  limits 
  of 
  the 
  different 
  systems, 
  and 
  the 
  

   desirability 
  of 
  subdivision, 
  at 
  all 
  events 
  in 
  the 
  case 
  of 
  the 
  Eocene, 
  

   were 
  scarcely 
  mentioned. 
  

  

  Besides 
  the 
  papers 
  on 
  crystalline 
  schists 
  and 
  the 
  second 
  edition, 
  

   with 
  the 
  preface, 
  of 
  the 
  British 
  Sub-Committees' 
  reports 
  on 
  clas- 
  

   sification 
  and 
  nomenclature, 
  there 
  was 
  presented 
  to 
  the 
  London 
  

   Congress 
  a 
  series 
  of 
  reports 
  by 
  American 
  Sub-Committees 
  on 
  the 
  

   classification 
  of 
  the 
  sedimentary 
  formations 
  of 
  North 
  America. 
  The 
  

   importance 
  of 
  this 
  work 
  is 
  due 
  primarily 
  to 
  the 
  fact 
  that 
  it 
  does 
  not 
  

   refer 
  to 
  the 
  portion 
  of 
  the 
  world 
  that 
  has 
  of 
  necessity 
  been 
  accepted 
  

   as 
  the 
  standard 
  of 
  comparison 
  for 
  the 
  geological 
  scale 
  ; 
  and, 
  secondly, 
  

   to 
  the 
  circumstance 
  that 
  much 
  of 
  the 
  information 
  has 
  been 
  accu- 
  

   mulated 
  very 
  recently, 
  and 
  has 
  not 
  found 
  its 
  way 
  into 
  text- 
  books. 
  

  

  