﻿190 
  W. 
  TOPLEY 
  ON 
  AREAS 
  OF 
  APPARENT 
  UPHEAVAL. 
  

  

  the 
  great 
  Penine 
  escarpment, 
  towards 
  the 
  east 
  and 
  south-east. 
  In 
  this 
  

   direction 
  the 
  beds, 
  as 
  a 
  whole, 
  thin 
  out 
  *. 
  In 
  part, 
  then, 
  the 
  westerly- 
  

   rise 
  of 
  the 
  beds 
  is 
  due 
  to 
  the 
  westerly 
  thickening. 
  A 
  noteworthy 
  

   exception 
  to 
  this 
  easterly 
  and 
  south-easterly 
  dip 
  occurs 
  between 
  

   Wharfedale 
  and 
  Wensleydale, 
  where 
  the 
  beds 
  have 
  a 
  northerly 
  and 
  

   north-easterly 
  dip, 
  from, 
  what 
  Professor 
  Phillips 
  has 
  called 
  the 
  

   " 
  Wharfedale 
  Axis 
  " 
  f 
  . 
  Now 
  it 
  is 
  near 
  Wharfedale 
  tbat 
  the 
  Lower 
  

   or 
  Scar 
  Limestone 
  series 
  attains 
  its 
  maximum 
  thickness. 
  The 
  top 
  

   of 
  this 
  series 
  — 
  the 
  upper 
  limit 
  of 
  the 
  " 
  main 
  limestone 
  " 
  — 
  is 
  a 
  well- 
  

   defined 
  line 
  ; 
  and 
  by 
  it 
  Professor 
  Phillips 
  has 
  estimated 
  the 
  dips. 
  

   But 
  the 
  dip 
  of 
  this 
  bed 
  is 
  partly 
  produced 
  by 
  the 
  thinning 
  of 
  the 
  

   underlying 
  mass 
  of 
  the 
  Lower 
  Limestone 
  ; 
  therefore 
  the 
  " 
  Wharfe- 
  

   dale 
  Axis 
  " 
  is 
  partly 
  due 
  to 
  unequal 
  thickness 
  of 
  underlying 
  strata. 
  

  

  5. 
  The 
  Carboniferous 
  Hocks 
  of 
  Derbyshire. 
  — 
  The 
  rapid 
  south-east- 
  

   erly 
  attenuation 
  of 
  the 
  Millstone 
  Grit 
  and 
  Toredale 
  Eocks 
  in 
  Derby- 
  

   shire 
  is 
  well 
  known. 
  From 
  3500 
  feet 
  on 
  the 
  west 
  of 
  Sheffield 
  (between 
  

   the 
  Bradfield 
  and 
  the 
  Bivelin 
  valleys) 
  the 
  beds 
  diminish 
  to 
  1500 
  

   feet 
  a 
  few 
  miles 
  north 
  of 
  Belper, 
  a 
  distance 
  of 
  about 
  20 
  miles 
  J. 
  

  

  The 
  highest 
  bed 
  of 
  the 
  Millstone 
  Grit 
  has 
  therefore, 
  from 
  this 
  

   cause 
  alone, 
  a 
  dip 
  of 
  2000 
  feet 
  in 
  20 
  miles, 
  which 
  is 
  rather 
  more 
  than 
  

   1°. 
  What 
  further 
  proportion 
  of 
  the 
  dip 
  may 
  be 
  due 
  to 
  the 
  thinning 
  

   of 
  still 
  lower 
  beds 
  we 
  do 
  not 
  know. 
  If 
  the 
  Millstone 
  Grit 
  here 
  were 
  

   entirely 
  covered 
  up 
  by 
  Coal-measures, 
  we 
  might 
  be 
  in 
  ignorance 
  of 
  

   this 
  rapid 
  thinning, 
  and 
  we 
  should 
  probably 
  refer 
  the 
  " 
  dip 
  " 
  of 
  these 
  

   Coal-measures 
  to 
  upheaval 
  or 
  depression. 
  

  

  6. 
  The 
  Weald. 
  — 
  Perhaps 
  the 
  most 
  striking 
  and 
  most 
  important 
  

   example 
  of 
  apparent 
  upheaval 
  being 
  partly 
  due 
  to 
  thickening 
  of 
  

   strata, 
  is 
  that 
  afforded 
  by 
  the 
  Weald. 
  

  

  Up 
  to 
  the 
  year 
  1855, 
  when 
  Mr. 
  Godwin- 
  Austen 
  read 
  before 
  this 
  

   Society 
  his 
  memorable 
  paper 
  on 
  the 
  extension 
  of 
  the 
  Coal-Measures§, 
  

   no 
  one 
  doubted 
  that 
  the 
  Lower 
  Cretaceous 
  and 
  Oolitic 
  rocks 
  passed 
  

   beneath 
  the 
  London 
  basin. 
  The 
  Wealden 
  Beds 
  were 
  supposed 
  to 
  

   thin 
  away 
  somewhere, 
  but 
  to 
  be 
  replaced 
  by 
  Oolitic 
  strata, 
  the 
  

   whole 
  of 
  the 
  beds 
  under 
  the 
  Chalk 
  being 
  bent 
  into 
  a 
  synclinal 
  

   supporting 
  the 
  London 
  Tertiary 
  basin. 
  

  

  Under 
  these 
  circumstances 
  it 
  was 
  natural 
  to 
  infer 
  that 
  the 
  strata 
  

   had 
  been 
  uniformly 
  folded 
  into 
  basins 
  and 
  anticlinals, 
  and 
  that 
  the 
  

   dip 
  of 
  beds 
  exposed 
  at 
  the 
  surface 
  wa3 
  a 
  true 
  index 
  to 
  the 
  dip 
  of 
  

   those 
  below. 
  

  

  But 
  when 
  it 
  became 
  apparent 
  that 
  the 
  succession 
  was 
  incomplete, 
  

   that 
  in 
  fact 
  the 
  entire 
  Lower 
  Cretaceous 
  and 
  Jurassic 
  series 
  were 
  absent 
  

   under 
  London, 
  but 
  gradually 
  came 
  in 
  and 
  thickened 
  as 
  we 
  receded 
  

   therefrom, 
  the 
  question 
  was 
  entirely 
  changed 
  ||. 
  

  

  * 
  Prof. 
  Phillips's 
  Geology 
  of 
  Yorkshire, 
  Part 
  ii., 
  Mountain 
  Limestone 
  Dis- 
  

   trict, 
  1836, 
  pp. 
  19, 
  32, 
  41, 
  46, 
  77, 
  175-7. 
  t 
  Loc. 
  cit. 
  p. 
  137. 
  

  

  \ 
  See 
  the 
  Sections 
  by 
  Messrs. 
  Green, 
  Foster, 
  and 
  Dakyns, 
  in 
  the 
  Geology 
  of 
  

   .... 
  parts 
  of 
  Derbyshire, 
  p. 
  139, 
  Mem. 
  Geol. 
  Survey, 
  1869. 
  

  

  § 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xii. 
  p. 
  38. 
  

  

  || 
  Some 
  of 
  the 
  difficulties 
  which 
  are 
  here 
  referred 
  to 
  concerning 
  the 
  upheaval 
  

   of 
  the 
  Weald, 
  appear 
  to 
  have 
  presented 
  themselves 
  to 
  Mr. 
  J. 
  E. 
  H. 
  Peyton. 
  See 
  

   his 
  lecture 
  on 
  the 
  Boring 
  at 
  Netherfield, 
  St. 
  Leonards-on-Sea, 
  1873. 
  

  

  