﻿1864.] 
  HULL 
  AND 
  GREEN 
  MILLSTONE-GRIT. 
  261 
  

  

  Then 
  follows 
  another 
  very 
  sharp 
  saddle 
  formed 
  of 
  the 
  Yoredale 
  

   Quartzites, 
  and 
  beyond 
  this 
  the 
  Biddulph 
  Trough, 
  containing 
  here 
  the 
  

   Lower 
  Coal-measures, 
  and 
  bounded 
  by 
  bold 
  ridges 
  of 
  the 
  Millstone- 
  

   grit. 
  Here 
  again 
  the 
  third 
  grit 
  makes 
  the 
  most 
  marked 
  feature 
  ; 
  it 
  

   forms 
  Cloud 
  Hill, 
  the 
  extreme 
  northerly 
  point 
  of 
  the 
  basin, 
  from 
  the 
  

   top 
  of 
  which 
  the 
  long 
  lines 
  of 
  its 
  escarpment 
  may 
  be 
  followed 
  by 
  the 
  

   eye 
  to 
  Mow 
  Cop 
  on 
  the 
  west, 
  and 
  by 
  Knipersley 
  towards 
  Bagnall 
  on 
  

   the 
  east. 
  

  

  Penological 
  details. 
  Yoredale 
  Rocks. 
  — 
  We 
  have 
  here 
  first 
  to 
  notice 
  

   the 
  nature 
  of 
  the 
  Yoredale 
  Qnartzites 
  on 
  the 
  sharp 
  anticlinals 
  of 
  Gun 
  

   Hill 
  and 
  Biddulph 
  Moor. 
  As 
  was 
  the 
  case 
  on 
  Bosley 
  Minn, 
  the 
  

   sandstones 
  are 
  very 
  hard, 
  close-grained, 
  subcrystalline 
  quartz-rocks. 
  

   The 
  quarries 
  on 
  Gun 
  Hill 
  show 
  the 
  actual 
  turn 
  of 
  the 
  beds 
  : 
  from 
  

   their 
  shattered 
  state 
  it 
  is 
  clear 
  that 
  they 
  must 
  have 
  undergone 
  great 
  

   violence; 
  the 
  surfaces 
  of 
  the 
  beds 
  and 
  a 
  series 
  of 
  vertical 
  joints 
  

   running 
  parallel 
  to 
  the 
  dip 
  are 
  often 
  marked 
  by 
  " 
  slickenside," 
  show- 
  

   ing 
  that 
  in 
  some 
  cases 
  a 
  bed 
  must 
  have 
  slipped 
  upon 
  the 
  one 
  imme- 
  

   diately 
  below 
  it. 
  On 
  the 
  Biddulph 
  Anticlinal 
  the 
  rise 
  of 
  the 
  beds 
  is 
  

   very 
  sharp 
  on 
  either 
  side 
  : 
  they 
  have 
  in 
  places 
  been 
  reversed, 
  so 
  as 
  to 
  

   dip 
  into 
  the 
  hill. 
  In 
  both 
  these 
  cases, 
  then, 
  we 
  again 
  find 
  a 
  sub- 
  

   crystalline 
  structure 
  in 
  the 
  rock, 
  accompanied 
  by 
  signs 
  of 
  violent 
  

   disturbance. 
  The 
  Yoredale 
  Grit, 
  as 
  has 
  been 
  already 
  mentioned, 
  is 
  

   found 
  in 
  force 
  about 
  Longnor 
  : 
  on 
  the 
  west 
  side 
  of 
  the 
  Goyt 
  Trough 
  

   it 
  is 
  present, 
  but 
  has 
  become 
  much 
  thinner 
  ; 
  while 
  it 
  is 
  altogether 
  

   wanting 
  round 
  the 
  edges 
  of 
  the 
  Biddulph 
  Trough. 
  

  

  Millstone 
  Grit. 
  — 
  A 
  complete 
  section 
  of 
  this 
  series 
  is 
  given 
  on 
  either 
  

   side 
  of 
  the 
  Goyt 
  Trough, 
  and 
  to 
  this 
  we 
  will 
  for 
  the 
  present 
  confine 
  

   our 
  attention, 
  leaving 
  the 
  grits 
  of 
  the 
  Biddulph 
  Trough 
  to 
  be 
  taken 
  

   in 
  hand 
  by-and-by. 
  

  

  The 
  fifth 
  or 
  lowest 
  bed 
  is 
  somewhat 
  changeable 
  in 
  its 
  character, 
  

   but 
  occurs 
  mostly 
  as 
  a 
  fine-grained 
  sandstone, 
  not 
  very 
  thick-bedded, 
  

   with 
  shale 
  -partings. 
  

  

  The 
  fourth 
  is 
  largely 
  quarried 
  beneath 
  The 
  Roaches 
  : 
  it 
  is 
  there 
  a 
  

   close-grained, 
  thick-bedded 
  grit, 
  and 
  it 
  makes 
  a 
  good 
  escarpment 
  ; 
  

   but, 
  like 
  the 
  fifth, 
  it 
  seems 
  to 
  be 
  very 
  changeable 
  in 
  its 
  nature. 
  

   Upon 
  the 
  whole, 
  these 
  beds 
  are 
  perhaps 
  slightly 
  thinner 
  than 
  at 
  

   Buxton. 
  

  

  The 
  third 
  bed 
  is 
  still 
  coarse 
  and 
  massive, 
  often 
  a 
  conglomerate, 
  

   of 
  about 
  the 
  same 
  thickness 
  as 
  at 
  Buxton. 
  The 
  little 
  coal 
  lying 
  on 
  

   the 
  top 
  of 
  the 
  bed 
  has 
  been 
  worked 
  in 
  one 
  place. 
  

  

  It 
  will 
  be 
  seen 
  from 
  the 
  section 
  (fig. 
  7) 
  that 
  the 
  second 
  bed 
  is 
  

   wanting. 
  It 
  may 
  be 
  followed 
  southwards 
  along 
  the 
  western 
  edge 
  

   of 
  the 
  Goyt 
  Trough, 
  without 
  any 
  sensible 
  decrease 
  in 
  thickness, 
  to 
  

   the 
  little 
  hamlet 
  of 
  Hallgreave 
  ; 
  it 
  is 
  there 
  cut 
  through 
  by 
  one 
  of 
  the 
  

   feeders 
  of 
  the 
  River 
  Dane, 
  and 
  consists 
  of 
  100 
  feet 
  or 
  more 
  of 
  flaggy 
  

   sandstone. 
  Our 
  next 
  section 
  of 
  this 
  bed 
  is 
  about 
  two 
  miles 
  to 
  the 
  

   east, 
  in 
  the 
  River 
  Dane 
  at 
  Gradbatch, 
  where, 
  about 
  halfway 
  between 
  

   the 
  Rough 
  Rock 
  and 
  the 
  third 
  grit, 
  we 
  find 
  about 
  30 
  or 
  40 
  feet 
  of 
  

   thin-bedded 
  flags 
  much 
  mixed 
  up 
  with 
  shale. 
  This 
  is 
  the 
  last 
  

   certain 
  trace 
  we 
  have 
  of 
  the 
  second 
  grit, 
  though 
  for 
  some 
  miles 
  

  

  