﻿PROCEEDINGS 
  OP 
  THE 
  GEOLOGICAL 
  SOCIETY, 
  7 
  

  

  The 
  final 
  Eeport 
  was 
  drawn 
  up 
  at 
  York, 
  and 
  was 
  submitted 
  to 
  the 
  

   Congress 
  at 
  Bologna. 
  This 
  Eeport 
  has 
  been 
  printed 
  in 
  the 
  ' 
  Geolo- 
  

   gical 
  Magazine 
  ' 
  (Dec. 
  ii. 
  vol. 
  viii. 
  p. 
  557, 
  1881). 
  A 
  brief 
  account 
  

   of 
  the 
  Committee's 
  work 
  was 
  read 
  before 
  Section 
  C, 
  and 
  is 
  printed 
  

   in 
  abstract 
  in 
  the 
  British 
  Association 
  Eeport. 
  

  

  The 
  object 
  of 
  the 
  Congress 
  in 
  discussing 
  this 
  question 
  is 
  to 
  secure, 
  

   if 
  possible, 
  a 
  greater 
  uniformity 
  than 
  heretofore 
  in 
  the 
  geological 
  

   maps 
  of 
  various 
  countries 
  ; 
  and 
  to 
  this 
  end 
  it 
  has 
  recommended 
  tho 
  

   adoption 
  of 
  a 
  scheme 
  of 
  colours 
  and 
  signs, 
  which 
  it 
  is 
  hoped 
  may 
  be 
  

   used, 
  with 
  but 
  little 
  modification, 
  by 
  all 
  nations. 
  There 
  is 
  no 
  in- 
  

   tention 
  of 
  even 
  recommending 
  the 
  adoption 
  of 
  this 
  scheme 
  by 
  Sur- 
  

   veys 
  now 
  in 
  progress, 
  maps 
  of 
  which 
  have 
  been 
  partly 
  published 
  on 
  

   any 
  other 
  system. 
  But 
  for 
  general 
  maps, 
  which 
  may 
  hereafter 
  be 
  

   published, 
  it 
  may 
  well 
  be 
  used, 
  and 
  perhaps 
  also 
  for 
  some 
  national 
  

   surveys. 
  The 
  Italian 
  Survey 
  is 
  about 
  to 
  publish 
  its 
  maps, 
  and 
  hopes 
  

   to 
  adopt 
  the 
  scheme 
  recommended 
  by 
  the 
  Congress. 
  The 
  Indian 
  

   Survey, 
  being 
  about 
  to 
  issue 
  a 
  connected 
  series 
  of 
  maps, 
  would 
  like 
  

   to 
  do 
  the 
  same. 
  The 
  United-States 
  Geological 
  Survey 
  is 
  also 
  now 
  

   engaged 
  in 
  the 
  consideration 
  of 
  this 
  question. 
  

  

  The 
  recommendations 
  finally 
  adopted, 
  as 
  regards 
  colour, 
  were 
  as 
  

   follows 
  : 
  — 
  

  

  Groups 
  or 
  Systems. 
  Colours. 
  

  

  Crystalline 
  rocks 
  of 
  Pre-Cambrian 
  age. 
  . 
  Bright 
  rose-carmine. 
  

  

  Crystalline 
  rocks 
  of 
  unknown 
  age 
  Pale 
  rose-carmine. 
  

  

  t, 
  , 
  f 
  (Question 
  reserved 
  for 
  

  

  Palaeozolc 
  ••• 
  \ 
  Map 
  Committee.) 
  

  

  Trias 
  Yiolet. 
  

  

  Lias 
  Dark 
  blue. 
  

  

  Jurassic 
  Blue. 
  

  

  Cretaceous 
  Green. 
  

  

  Tertiary 
  Yellow. 
  

  

  Eruptive 
  rocks 
  (Question 
  reserved.) 
  

  

  The 
  subdivisions 
  of 
  groups 
  or 
  systems 
  should 
  be 
  shown 
  by 
  various 
  

   shades 
  of 
  the 
  colour 
  adopted, 
  the 
  darker 
  shades 
  denoting 
  the 
  older 
  

   beds. 
  Coloured 
  lines 
  or 
  u 
  reserves 
  " 
  of 
  white 
  can 
  also 
  be 
  employed 
  

   when 
  the 
  map 
  is 
  printed 
  in 
  colours. 
  

  

  The 
  letter 
  denoting 
  the 
  group 
  or 
  system 
  should 
  be 
  the 
  initial 
  

   Eoman 
  capital 
  of 
  its 
  name, 
  most 
  of 
  these 
  names 
  being 
  now 
  in 
  

   almost 
  universal 
  use. 
  The 
  letter 
  of 
  the 
  smaller 
  divisions 
  (series, 
  

   stages, 
  and 
  beds) 
  should 
  be 
  the 
  small 
  initial 
  letter 
  of 
  the 
  name. 
  

   Still 
  smaller 
  subdivisions 
  should 
  be 
  marked 
  by 
  figures, 
  the 
  lowest- 
  

   being 
  denoted 
  by 
  1. 
  

  

  Examples 
  : 
  — 
  

  

  Silurian 
  S. 
  

  

  „ 
  Ludlow 
  , 
  SI. 
  

  

  Lower 
  Ludlow 
  SI 
  1 
  , 
  

  

  )? 
  

  

  