﻿26 
  

  

  MR. 
  H. 
  T. 
  BROWN 
  OX 
  THE 
  PERMIAX 
  

  

  viridite, 
  a 
  kind 
  of 
  palagonite 
  (?), 
  &c. 
  being 
  produced. 
  One 
  of 
  the 
  

   specimens 
  contains 
  a 
  few 
  fragments 
  of 
  quartz, 
  probably 
  water-worn. 
  

   The 
  rock 
  has, 
  no 
  doubt, 
  been 
  washed 
  down 
  from 
  a 
  basic 
  lava. 
  It 
  

   resembles 
  very 
  closely 
  some 
  of 
  the 
  fragments 
  in 
  the 
  coarse 
  breccia 
  

   at 
  the 
  base 
  of 
  the 
  Hartshill 
  quartzite, 
  and 
  doubtless 
  belongs 
  to 
  the 
  

   Caldecote 
  Series. 
  

  

  Volcanic 
  Ash. 
  — 
  The 
  breccias 
  of 
  localities 
  (1), 
  (2), 
  and 
  (3) 
  have 
  

   yielded 
  a 
  few 
  large 
  and 
  fairly 
  well-rounded 
  fragments 
  of 
  this 
  nature, 
  

   and 
  of 
  these 
  I 
  have 
  had 
  two 
  prepared 
  for 
  the 
  microscope. 
  The 
  first 
  

   proves 
  to 
  be 
  a 
  rock 
  which 
  originally 
  was 
  a 
  fine-grained 
  volcanic 
  

   ash 
  chiefly 
  composed 
  of 
  " 
  dust,'"' 
  i. 
  e. 
  chips 
  of 
  glass, 
  crystals, 
  &c. 
  

   rather 
  than 
  scoria. 
  The 
  lava 
  would 
  be 
  a 
  trachyte. 
  It 
  has 
  been 
  

   consolidated 
  and 
  chemically 
  changed, 
  the 
  felspar 
  crystals 
  being 
  re- 
  

   placed 
  by 
  secondary 
  products, 
  and 
  a 
  filmy 
  micaceous 
  mineral 
  de- 
  

   veloped. 
  

  

  The 
  second 
  specimen 
  may 
  perhaps 
  be 
  described 
  as 
  an 
  argillite. 
  

   the 
  materials 
  of 
  which 
  are 
  largely 
  derived 
  from 
  volcanic 
  (trachj-tic) 
  

   dust. 
  It 
  has 
  not 
  been 
  subsequently 
  modified 
  to 
  the 
  same 
  extent 
  as 
  

   the 
  rock 
  just 
  described. 
  Professor 
  Lapworth 
  has 
  pointed 
  out 
  to 
  me 
  

   that 
  this 
  rock 
  resembles 
  very 
  closely 
  the 
  ashes 
  of 
  the 
  Caldecote 
  

   Series 
  occurring 
  in 
  the 
  Old 
  Tunnel, 
  and 
  that 
  the 
  other 
  specimen 
  

   may 
  also 
  with 
  certainty 
  be 
  referred 
  to 
  the 
  same 
  series. 
  

  

  Igneous 
  Mocks. 
  — 
  Most 
  of 
  the 
  fragments 
  of 
  igneous 
  rock 
  are 
  very 
  

   much 
  decomposed, 
  but 
  the 
  following 
  are 
  recognizable 
  : 
  — 
  

  

  Felsites. 
  — 
  A 
  few 
  fragments 
  from 
  localities 
  (1), 
  (2), 
  and 
  (6). 
  These 
  

   are 
  occasionally 
  scoriaceous 
  and 
  slightly 
  porphyritic. 
  A 
  specimen 
  

   from 
  Packington, 
  which 
  is 
  compact 
  and 
  minutely 
  porphyritic, 
  is 
  

   probably 
  an 
  old 
  andesite, 
  or 
  basic 
  sanidine 
  (? 
  trachyte). 
  From 
  the 
  

   same 
  locality 
  I 
  have 
  also 
  obtained 
  a 
  quart 
  z-felsite, 
  which 
  is 
  distinctly 
  

   cleaved. 
  

  

  In 
  Series 
  (5), 
  that 
  of 
  the 
  Hartshorn-Brook 
  section, 
  there 
  are 
  a 
  

   large 
  number 
  of 
  fragments 
  of 
  a 
  rock 
  which, 
  from 
  the 
  appearance 
  of 
  

   the 
  hand 
  -specimens, 
  might 
  be 
  described 
  as 
  a 
  crushed 
  quartz-felsite. 
  

   ^Microscopical 
  examination 
  shows 
  that 
  the 
  crushing 
  has 
  resulted 
  in 
  

   the 
  development 
  of 
  a 
  filmy 
  micaceous 
  mineral 
  giving 
  a 
  rather 
  bril- 
  

   liant 
  colour 
  at 
  about 
  -A5 
  with 
  the 
  crossed 
  nicols. 
  There 
  are 
  no 
  

   porphyritic 
  felspars 
  now 
  recognizable. 
  The 
  grains 
  of 
  quartz 
  appear 
  

   to 
  be 
  of 
  "early 
  consolidation," 
  and 
  to 
  have 
  been 
  slightly 
  enlarged 
  

   when 
  the 
  mass 
  finally 
  cooled. 
  The 
  matrix 
  exhibits 
  a 
  minute 
  devi- 
  

   trification-structure. 
  The 
  rock 
  may 
  be 
  a 
  modified 
  fine-grained 
  tuff, 
  

   but 
  is 
  more 
  likely 
  a 
  modified 
  igneous 
  rock 
  (obsidian). 
  Both 
  from 
  

   macros 
  copical 
  and 
  microscopical 
  appearances 
  Professor 
  Bonney 
  con- 
  

   siders 
  that 
  it 
  belongs 
  to 
  the 
  Peldar-Sharpley 
  group 
  of 
  rocks 
  in 
  

   Charnwood. 
  

  

  Besides 
  the 
  above 
  we 
  have, 
  in 
  No. 
  6, 
  the 
  Polesworth 
  breccia, 
  

   amongst 
  the 
  less 
  decomposed 
  fragments, 
  several 
  which 
  Professor 
  

   Bonney 
  is 
  inclined 
  to 
  consider 
  porphyritic 
  andesites, 
  belonging 
  to 
  

   the 
  Ccddecote 
  Series. 
  

  

  Diorites. 
  — 
  The 
  breccias 
  both 
  of 
  Packington 
  and 
  of 
  Xewhall 
  Park 
  

   Colliery 
  contain 
  more 
  or 
  less 
  decomposed 
  fragments 
  of 
  a 
  rock 
  which 
  

  

  