﻿ROCKS 
  OF 
  THE 
  LEICESTERSHIRE 
  COAL-FIELD. 
  23 
  

  

  described 
  as 
  consisting 
  of 
  " 
  light 
  green 
  and 
  indurated 
  slate, 
  grits 
  of 
  

   various 
  colours 
  and 
  textures, 
  dark 
  brown 
  and 
  purple 
  sandstones, 
  

   often 
  micaceous 
  ; 
  chert, 
  felspar, 
  trap 
  (?), 
  and 
  quartz." 
  At 
  Packington 
  

   the 
  breccia 
  is 
  stated 
  to 
  be 
  principally 
  composed 
  of 
  slate. 
  

  

  More 
  recently 
  Mr. 
  W. 
  S. 
  Gresley, 
  F.G.S., 
  has 
  published 
  (Proc. 
  Geol. 
  

   Soc. 
  1884-85, 
  p. 
  96, 
  and 
  « 
  Midland 
  Naturalist,' 
  vol. 
  ix.) 
  a 
  very 
  com- 
  

   plete 
  account 
  of 
  certain 
  haematite 
  nodules 
  which 
  occur 
  in 
  the 
  breccias 
  

   of 
  some 
  localities 
  in 
  the 
  district 
  ; 
  and 
  he 
  briefly 
  refers 
  to 
  the 
  other 
  

   fragments 
  associated 
  with 
  the 
  haematite 
  as 
  consisting 
  of 
  sandstones 
  

   of 
  various 
  colours, 
  vein-quartz 
  enclosing 
  greenish 
  slate, 
  quartzite 
  

   Moulders 
  and 
  pebbles, 
  pudding-stone, 
  granitic 
  rocks, 
  red 
  and 
  green 
  

   clay-slate, 
  igneous 
  rocks, 
  coarse 
  jasper, 
  horn 
  stone, 
  chert, 
  lumps 
  of 
  

   siliceous 
  and 
  of 
  red, 
  earthy, 
  cone-in-cone 
  formation, 
  and 
  pebbles 
  of 
  

   indurated 
  clay 
  and 
  slaty 
  rocks. 
  

  

  Professor 
  Bonney 
  examined 
  Mr. 
  Gresley's 
  specimens 
  and 
  gave 
  

   an 
  account 
  of 
  their 
  microscopical 
  characters 
  in 
  his 
  Presidential 
  Ad- 
  

   dress 
  to 
  Section 
  C 
  of 
  the 
  British 
  Association 
  in 
  1886. 
  A 
  few 
  of 
  

   the 
  specimens 
  were 
  found 
  to 
  be 
  distinctly 
  referable 
  to 
  the 
  Charnwood 
  

   series; 
  but 
  the 
  one 
  which 
  is 
  most 
  fully 
  described 
  is 
  a 
  hard 
  con- 
  

   glomerate, 
  doubtless 
  the 
  "pudding-stone" 
  of 
  Mr. 
  Gresley, 
  which 
  

   Prof. 
  Bonney 
  considers 
  to 
  be 
  made 
  up 
  of 
  material 
  in 
  part 
  originally 
  

   derived 
  from 
  the 
  Charnwood 
  series, 
  and 
  in 
  part 
  from 
  volcanic 
  vents 
  

   of 
  a 
  later 
  age 
  and 
  unknown 
  locality. 
  

  

  The 
  unsatisfactory 
  state 
  of 
  our 
  knowledge 
  of 
  the 
  rock-fragments 
  

   of 
  the 
  breccias 
  is 
  sufficiently 
  indicated 
  by 
  the 
  somewhat 
  conflicting 
  

   statements 
  just 
  cited, 
  and 
  it 
  therefore 
  appeared 
  to 
  me 
  that 
  a 
  pro- 
  

   longed 
  and 
  detailed 
  study 
  of 
  these 
  fragments 
  was 
  desirable, 
  and 
  

   might 
  lead, 
  not 
  only 
  to 
  a 
  certain 
  correlation 
  of 
  the 
  beds 
  with 
  the 
  

   Permians 
  of 
  surrounding 
  districts, 
  but 
  also 
  to 
  a 
  knowledge 
  of 
  the 
  

   physical 
  conditions 
  under 
  which 
  these 
  beds 
  were 
  deposited, 
  and 
  of 
  

   the 
  source 
  from 
  which 
  the 
  sediment 
  was 
  derived. 
  It 
  seemed, 
  in 
  

   fact, 
  an 
  excellent 
  opportunity 
  of 
  applying 
  the 
  principles 
  laid 
  down 
  

   in 
  the 
  Address 
  referred 
  to 
  above, 
  and 
  summarized 
  by 
  Prof. 
  Bonney 
  as 
  

   " 
  the 
  application 
  of 
  microscopic 
  analysis 
  to 
  discovering 
  the 
  physical 
  

   geography 
  of 
  bygone 
  ages." 
  

  

  I 
  may 
  state 
  that 
  it 
  would 
  have 
  been 
  absolutely 
  impossible 
  for 
  me 
  

   to 
  have 
  carried 
  this 
  portion 
  of 
  my 
  subject 
  to 
  a 
  successful 
  issue 
  had 
  

   it 
  not 
  been 
  for 
  the 
  generous 
  and 
  constant 
  assistance 
  of 
  Prof. 
  Bonney, 
  

   who 
  has, 
  from 
  the 
  outset, 
  taken 
  the 
  greatest 
  possible 
  interest 
  in 
  my 
  

   work 
  and 
  has 
  at 
  all 
  times 
  placed 
  at 
  my 
  disposal 
  his 
  wide 
  knowledge 
  

   of 
  rocks 
  and 
  of 
  their 
  microscopical 
  examination. 
  To 
  Prof. 
  Lapworth 
  

   I 
  am 
  also 
  much 
  indebted 
  for 
  assistance 
  in 
  identifying 
  some 
  of 
  my 
  

   rock-specimens 
  with 
  those 
  of 
  his 
  own 
  classical 
  district 
  of 
  ISuneaton. 
  

  

  Owing 
  to 
  the 
  possibility 
  of 
  accidentally 
  including 
  rock-specimens 
  

   from 
  the 
  Drift, 
  if 
  the 
  fragments 
  for 
  systematic 
  study 
  are 
  obtained 
  

   from 
  the 
  outcrop 
  of 
  the 
  thin 
  band 
  of 
  Permian 
  beds, 
  it 
  is 
  essential 
  

   that 
  they 
  should 
  be 
  taken 
  from 
  cleanly-cut 
  sections 
  if 
  we 
  are 
  to 
  

   avoid 
  a 
  source 
  of 
  error 
  from 
  which, 
  I 
  believe, 
  some 
  of 
  the 
  observations 
  

   of 
  previous 
  workers 
  are 
  not 
  wholly 
  free. 
  This 
  necessary 
  condition 
  

   limits 
  the 
  choice 
  of 
  localites 
  to 
  the 
  following 
  spots, 
  from 
  each 
  of 
  

  

  