﻿4 
  ME. 
  H. 
  T. 
  BROWN 
  ON 
  THE 
  PEEMIAN" 
  

  

  Which 
  leaves 
  no 
  doubt 
  that 
  Professor 
  Hull's 
  surmise 
  as 
  to 
  the 
  Per- 
  

   mian 
  age 
  of 
  at 
  least 
  some 
  of 
  these 
  beds 
  is 
  quite 
  correct. 
  

  

  Whilst 
  engaged 
  in 
  mapping 
  the 
  Coal-measures 
  and 
  overlying 
  rocks 
  

   on 
  the 
  north-western 
  boundary 
  of 
  the 
  Coal-field 
  between 
  Bretby 
  

   and 
  Gresley, 
  I 
  obtained 
  many 
  indications 
  of 
  the 
  brecciated 
  series 
  

   cropping 
  out 
  at 
  the 
  base 
  of 
  the 
  Trias. 
  These 
  small 
  patches 
  were, 
  

   for 
  the 
  most 
  part, 
  discovered 
  by 
  the 
  constant 
  use 
  of 
  a 
  small 
  hand- 
  

   borer, 
  consisting 
  of 
  a 
  light 
  jointed 
  steel 
  rod, 
  armed 
  at 
  the 
  end 
  with 
  

   an 
  auger 
  about 
  | 
  inch 
  in 
  diameter. 
  

  

  The 
  surface 
  appearances 
  very 
  often 
  afford 
  no 
  indications 
  of 
  the 
  

   existence 
  of 
  the 
  breccias 
  and 
  their 
  associated 
  rocks 
  ; 
  but 
  by 
  adopting 
  

   this 
  method, 
  which 
  is 
  easily 
  and 
  rapidly 
  carried 
  out 
  in 
  the 
  field 
  if 
  one 
  

   has 
  a 
  little 
  assistance, 
  I 
  have 
  been 
  able 
  to 
  discover 
  the 
  existence 
  of 
  

   the 
  rocks 
  in 
  question 
  in 
  many 
  places 
  hitherto 
  unsuspected, 
  and 
  to 
  

   delineate 
  their 
  boundaries 
  with 
  absolute 
  accuracy 
  on 
  a 
  large 
  scale 
  

   map. 
  

  

  In 
  tracing 
  the 
  beds 
  by 
  these 
  means 
  from 
  north 
  to 
  south, 
  I 
  have 
  

   found 
  the 
  intercalation 
  of 
  the 
  breccias 
  between 
  the 
  Trias 
  and 
  the 
  

   Carboniferous 
  so 
  extremely 
  uncertain, 
  and 
  their 
  more 
  or 
  less 
  complete 
  

   overlap 
  by 
  the 
  Punter 
  so 
  frequent 
  and 
  abrupt, 
  that 
  the 
  facts 
  are 
  not 
  

   capable 
  of 
  being 
  satisfactorily 
  explained 
  by 
  anything 
  short 
  of 
  an 
  

   unconformity 
  between 
  the 
  brecciated 
  series 
  and 
  the 
  Bunter. 
  

  

  Better 
  proof 
  of 
  this 
  unconformity 
  is 
  afforded 
  by 
  certain 
  sections 
  

   which 
  are 
  to 
  be 
  seen 
  on 
  the 
  western 
  boundary 
  of 
  the 
  visible 
  coal- 
  

   field, 
  at 
  the 
  Newhall 
  Park 
  Colliery, 
  about 
  one 
  mile 
  north 
  of 
  Gresley 
  

   station 
  *. 
  

  

  Here, 
  in 
  a 
  railway-cutting 
  about 
  150 
  yards 
  in 
  length, 
  running 
  

   in 
  a 
  direction 
  approximately 
  E.S.E. 
  and 
  W.N.W., 
  the 
  Nether 
  Main 
  

   Coal 
  comes 
  into 
  view 
  near 
  the 
  colliery-shaft, 
  with 
  an 
  apparent 
  

   easterly 
  dip 
  of 
  13°. 
  The 
  coal-seam 
  does 
  not 
  quite 
  reach 
  the 
  surface, 
  

   but 
  is 
  cut 
  off 
  by 
  a 
  fault 
  with 
  a 
  downthrow 
  of 
  36 
  feet 
  to 
  the 
  west, 
  thus 
  

   causing 
  a 
  repetition 
  of 
  the 
  coal 
  outcrop 
  about 
  70 
  yards 
  further 
  west. 
  

   At 
  this 
  point 
  the 
  Nether 
  Coal 
  is 
  covered 
  with 
  a 
  few 
  feet 
  of 
  brightly 
  

   coloured 
  and 
  strongly 
  variegated 
  red, 
  yellow, 
  and 
  white 
  clays, 
  

   rapidly 
  giving 
  place, 
  further 
  west, 
  to 
  a 
  bed 
  of 
  dull 
  reel 
  breccia. 
  This 
  

   breccia 
  consists 
  of 
  large 
  and 
  small 
  angular 
  and 
  subangular 
  frag- 
  

   ments 
  of 
  rock, 
  imbedded 
  in 
  a 
  red 
  calcareous 
  matrix. 
  In 
  places 
  it 
  is 
  

   consolidated, 
  but 
  near 
  the 
  surface 
  forms 
  a 
  loose 
  rubbly 
  mass 
  showing 
  

   little 
  or 
  no 
  signs 
  of 
  stratification. 
  

  

  The 
  following 
  sketch 
  (fig. 
  1) 
  indicates 
  the 
  position 
  of 
  the 
  beds 
  

   on 
  the 
  south 
  side 
  of 
  the 
  cutting. 
  On 
  the 
  opposite 
  side 
  of 
  the 
  railway 
  

   the 
  breccias 
  are 
  to 
  be 
  seen 
  resting, 
  apparently 
  horizontally, 
  upon 
  an 
  

   eroded 
  surface 
  of 
  light-coloured 
  Coal-measure 
  clay 
  which 
  appears 
  to 
  

   dip 
  13° 
  E.S.E. 
  The 
  line 
  of 
  junction 
  of 
  the 
  two 
  series 
  of 
  beds 
  is 
  

   marked 
  by 
  a 
  thin 
  band 
  of 
  coal-smut, 
  the 
  triturated 
  remains 
  of 
  a 
  

   portion 
  of 
  the 
  Nether 
  Coal 
  which 
  cropped 
  out 
  at 
  this 
  spot 
  on 
  the 
  old 
  

   Permian 
  beach. 
  

  

  In 
  the 
  underground 
  workings 
  of 
  the 
  colliery 
  the 
  breccias 
  were 
  

  

  * 
  The 
  beds 
  here 
  described 
  do 
  not 
  appear 
  in 
  our 
  one-inch 
  Survey 
  map. 
  

  

  