﻿1864.] 
  HULL 
  AND 
  GREEN 
  MILLSTONE-GRIT. 
  247 
  

  

  As 
  to 
  the 
  lower 
  boundary 
  there 
  is 
  luckily 
  but 
  one 
  opinion. 
  The 
  

   fourth 
  grit 
  is 
  in 
  Lancashire 
  the 
  thickest, 
  coarsest, 
  and 
  most 
  massive 
  

   of 
  all 
  the 
  gritstones 
  ; 
  and 
  the 
  sandstones 
  below 
  it 
  are 
  all 
  thinner- 
  

   bedded 
  and 
  finer 
  in 
  grain. 
  It 
  makes, 
  therefore, 
  a 
  natural 
  base 
  to 
  a 
  

   series 
  whose 
  character 
  is 
  indicated 
  by 
  its 
  name, 
  and 
  as 
  such 
  it 
  has 
  

   always 
  been 
  looked 
  upon 
  by 
  all 
  authors, 
  from 
  Farey* 
  downwards. 
  

  

  In 
  the 
  south 
  of 
  the 
  district, 
  however, 
  the 
  bed 
  falls 
  off 
  in 
  character, 
  

   and 
  is 
  at 
  last 
  represented 
  by 
  two 
  sandstones, 
  with 
  a 
  thin 
  bed 
  of 
  

   chale 
  between 
  them. 
  Looking 
  at 
  these 
  beds 
  by 
  themselves, 
  there 
  is 
  

   nothing 
  to 
  entitle 
  them 
  to 
  be 
  called 
  Millstone 
  -grit 
  at 
  all 
  ; 
  and 
  it 
  is 
  not 
  

   from 
  their 
  own 
  importance, 
  but 
  only 
  as 
  the 
  representative 
  of 
  the 
  

   more 
  striking 
  masses 
  in 
  the 
  north, 
  that 
  they 
  can 
  claim 
  the 
  prestige 
  

   of 
  marking 
  the 
  base 
  of 
  the 
  formation. 
  An 
  observer 
  who 
  looked 
  

   only 
  at 
  a 
  district 
  where 
  the 
  fourth 
  grit 
  wears 
  so 
  feeble 
  a 
  form, 
  .and 
  

   had 
  not 
  traced 
  it 
  step 
  by 
  step 
  up 
  to 
  its 
  full 
  development, 
  would 
  

   be 
  likely 
  to 
  take 
  the 
  lowest 
  coarse 
  grit 
  in 
  the 
  neighbourhood 
  for 
  the 
  

   base 
  of 
  the 
  formation 
  ; 
  and 
  into 
  this 
  mistake 
  Farey 
  seems 
  at 
  times 
  

   to 
  have 
  naturally 
  fallen, 
  and 
  to 
  have 
  looked 
  upon 
  the 
  third 
  grit 
  of 
  

   Combs 
  Moss, 
  for 
  instance, 
  as 
  the 
  equivalent 
  of 
  the 
  Kinder 
  Scout 
  

   bed, 
  because 
  each 
  was 
  the 
  lowest 
  coarse 
  grit 
  in 
  the 
  country 
  roundf 
  . 
  

  

  The 
  fourth 
  grit 
  thins 
  away 
  altogether 
  before 
  reaching 
  the 
  borders 
  

   of 
  the 
  North 
  Staffordshire 
  Coal-fields, 
  and 
  the 
  bed 
  above 
  is 
  then 
  

   taken 
  for 
  the 
  base 
  of 
  the 
  Millstone 
  series. 
  

  

  § 
  4. 
  Yoredale 
  Rocks. 
  

  

  Between 
  the 
  lowest 
  grit 
  and 
  the 
  Mountain-limestone 
  lies 
  a 
  group 
  

   of 
  shales 
  and 
  sandstones, 
  with 
  thin 
  limestones 
  at 
  the 
  bottom, 
  the 
  

   Yoredale 
  Rocks 
  of 
  Professor 
  Phillips. 
  

  

  These 
  beds, 
  in 
  the 
  country 
  we 
  are 
  describing, 
  admit 
  of 
  the 
  follow- 
  

   ing 
  threefold 
  division 
  : 
  — 
  

  

  (A.) 
  Shales 
  with 
  a 
  thick 
  bed 
  of 
  sandstone 
  (the 
  "Shale-grit" 
  of 
  

   Farey 
  J), 
  and 
  perhaps 
  a 
  few 
  thin 
  limestones. 
  

  

  (B.) 
  Sandstones, 
  for 
  the 
  most 
  part 
  thin-bedded 
  and 
  close-grained, 
  

   with 
  black 
  shales. 
  This 
  group 
  we 
  shall 
  speak 
  of 
  as 
  the 
  " 
  Yore- 
  

   dale 
  Quartzites." 
  

  

  (C.) 
  Black 
  shales, 
  with 
  thin, 
  black, 
  earthy 
  limestones 
  towards 
  the 
  

   bottom 
  §. 
  

  

  Were 
  it 
  not 
  that 
  the 
  Kinder 
  Scout 
  Grit 
  makes 
  so 
  natural 
  and 
  so 
  

   generally 
  received 
  a 
  base 
  to 
  the 
  Millstone 
  -grit, 
  the 
  first 
  of 
  these 
  

   groups 
  might 
  well 
  have 
  been 
  placed 
  in 
  that 
  formation 
  rather 
  than 
  

   among 
  the 
  Yoredale 
  Eocks. 
  The 
  sandstone, 
  though 
  fine-grained, 
  is 
  

  

  * 
  Hist, 
  of 
  Derbyshire, 
  vol. 
  i. 
  p. 
  220. 
  t 
  Ibid. 
  p. 
  170. 
  

  

  X 
  As 
  we 
  speak 
  of 
  the 
  whole 
  group 
  as 
  the 
  Yoredale 
  Rocks, 
  we 
  shall 
  call 
  this 
  bed 
  

   the 
  " 
  Yoredale 
  Grit." 
  

  

  § 
  Farey, 
  in 
  his 
  account 
  of 
  the 
  Yoredale 
  Eocks, 
  mentions 
  what 
  he 
  calls 
  <hree 
  

   "anomalies" 
  as 
  occurring 
  in 
  them: 
  a 
  bed 
  of 
  fine 
  sandstone, 
  the 
  Shale 
  Grit; 
  

   beds 
  of 
  hard 
  eank-like 
  sandstone 
  ; 
  and 
  thin 
  beds 
  of 
  dark-blue 
  or 
  black 
  limestone 
  

   (Hist, 
  of 
  Derbyshire, 
  p. 
  228). 
  These 
  three 
  " 
  anomalies" 
  form 
  the 
  distinguishing 
  

   features 
  of 
  the 
  three 
  groups 
  in 
  the 
  above 
  scheme. 
  

  

  VOL. 
  XX. 
  PART 
  I. 
  S 
  

  

  