﻿22 
  ME. 
  H. 
  T. 
  BEOWN 
  ON 
  THE 
  PEEMIAN 
  

  

  The 
  following 
  is 
  an 
  analysis 
  of 
  the 
  calcareous 
  portion 
  of 
  the 
  matrix 
  

   from 
  a 
  specimen 
  from 
  Xewhall 
  Park 
  * 
  : 
  — 
  

  

  Calcium 
  carbonate 
  8*51 
  

  

  Magnesium 
  carbonate 
  5*04 
  

  

  Hydrated 
  ferrous 
  oxide 
  (FeH 
  2 
  2 
  ) 
  3-57 
  

  

  Ferric 
  oxide 
  (Fe,0 
  3 
  ) 
  -83 
  

  

  Silica, 
  soluble 
  in" 
  dilute 
  HC1 
  1-12 
  

  

  Insoluble 
  residue 
  80-93 
  

  

  100-00 
  

  

  The 
  ferrous 
  salt 
  of 
  the 
  matrix 
  on 
  exposure 
  is 
  oxidized 
  to 
  ferric 
  

   hydrate, 
  thus 
  causing 
  the 
  whole 
  rock 
  to 
  assume 
  a 
  deep 
  red 
  colour, 
  

   which 
  stains 
  the 
  exterior 
  of 
  the 
  brecciated 
  fragments. 
  

  

  When 
  a 
  bed 
  of 
  breccia 
  is 
  traced 
  for 
  a 
  short 
  distance 
  horizontally 
  

   it 
  is 
  never 
  found 
  to 
  be 
  very 
  persistent, 
  but 
  dovetails 
  into 
  sandy 
  and 
  

   marly 
  beds, 
  just 
  as 
  do 
  many 
  of 
  the 
  beds 
  of 
  breccia 
  in 
  the 
  fine 
  sections 
  at 
  

   the 
  base 
  of 
  the 
  Trias 
  on 
  the 
  south 
  coast 
  of 
  Devonshire. 
  But 
  although 
  

   individual 
  beds 
  may 
  die 
  out 
  quickly, 
  their 
  places 
  are 
  taken 
  by 
  other 
  

   brecciated 
  bands 
  on 
  the 
  same 
  or 
  slightly 
  different 
  horizons 
  ; 
  so 
  that 
  

   the 
  breccia, 
  as 
  a 
  distinct 
  feature 
  in 
  the 
  Permian 
  rocks, 
  may 
  be 
  traced 
  

   over 
  a 
  considerable 
  portion 
  of 
  the 
  coal-field. 
  There 
  is, 
  however, 
  

   most 
  undoubtedl}' 
  a 
  general 
  tendency, 
  when 
  the 
  Permians 
  are 
  traced 
  

   within 
  the 
  above 
  area 
  from 
  south 
  to 
  north, 
  for 
  the 
  more 
  brecciated 
  

   members 
  of 
  the 
  series 
  to 
  die 
  out 
  northward, 
  whilst 
  the 
  marly 
  'portions 
  

   for 
  the 
  most 
  part 
  thicken 
  in 
  that 
  direction. 
  At 
  Packington, 
  for 
  in- 
  

   stance, 
  the 
  breccias 
  are 
  well 
  developed 
  and 
  the 
  fragments 
  are 
  large 
  

   and 
  angular 
  ; 
  whilst 
  four 
  miles 
  to 
  the 
  north-north-west, 
  at 
  Swadlin- 
  

   cote, 
  the 
  brecciated 
  bands 
  are 
  thinner 
  and 
  the 
  included 
  fragments 
  

   somewhat 
  less 
  angular 
  ; 
  and 
  about 
  two 
  miles 
  still 
  further 
  to 
  the 
  north, 
  

   near 
  the 
  Hartshorn 
  brook, 
  we 
  find 
  but 
  very 
  meagre 
  representatives 
  of 
  

   the 
  breccias, 
  whilst 
  at 
  Bepton 
  Pocks, 
  but 
  a 
  mile 
  and 
  a 
  half 
  north-east 
  

   of 
  this 
  latter 
  spot, 
  the 
  breccias 
  are 
  entirely 
  absent. 
  On 
  the 
  other 
  

   hand, 
  the 
  marls, 
  of 
  which 
  at 
  Swadlincote 
  there 
  are 
  only 
  15 
  feet, 
  at 
  

   Pepton 
  Pocks 
  have 
  thickened 
  out 
  to 
  from 
  60 
  to 
  70 
  feet. 
  The 
  great 
  

   importance 
  of 
  these 
  facts 
  will 
  be 
  evident 
  when 
  we 
  come 
  to 
  consider 
  

   the 
  origin 
  of 
  the 
  sediment 
  which 
  makes 
  up 
  the 
  Permian 
  rocks 
  of 
  the 
  

   district 
  under 
  consideration. 
  

  

  (3) 
  The 
  Bock-eeagmexts 
  or 
  the 
  Beeccias. 
  

  

  The 
  accounts 
  hitherto 
  published 
  of 
  the 
  rock-fragments 
  contained 
  

   in 
  the 
  Permian 
  breccias 
  of 
  the 
  Leicestershire 
  Coal-field 
  are 
  very 
  

   incomplete. 
  The 
  Pev. 
  W. 
  H. 
  Coleman, 
  in 
  his 
  ' 
  Outlines 
  of 
  the 
  

   Geology 
  of 
  Leicestershire 
  ' 
  (p. 
  26), 
  states 
  ie 
  that 
  they 
  consist 
  of 
  

   Silurian 
  and 
  Carboniferous 
  rocks, 
  associated 
  with 
  pebbles 
  of 
  basalt 
  

   and 
  other 
  Trappean 
  rocks, 
  all 
  of 
  which 
  appear 
  to 
  have 
  travelled 
  from 
  

   the 
  W., 
  for 
  no 
  fragments 
  referable 
  to 
  the 
  Charnwood 
  rocks 
  are 
  to 
  

   be 
  found 
  among 
  them." 
  In 
  the 
  Survey 
  Memoir 
  (p. 
  59) 
  they 
  are 
  

  

  * 
  I 
  am 
  indebted 
  to 
  Mr. 
  J. 
  G. 
  Wells 
  for 
  this 
  analysis. 
  

  

  