﻿STRATA 
  OF 
  THE 
  HAMPSHIRE 
  BASIN". 
  

  

  481 
  

  

  mural 
  face 
  of 
  Headon 
  Hill. 
  Only 
  half 
  a 
  mile 
  off, 
  on 
  the 
  other 
  side 
  

   of 
  the 
  Totland-Bay 
  anticlinal, 
  a 
  similar 
  mass 
  of 
  sands 
  and 
  limestones 
  

   appears 
  in 
  "Warden 
  Cliff, 
  and, 
  dipping 
  below 
  the 
  sea-level, 
  forms 
  the 
  

   dangerous 
  reefs 
  known 
  as 
  How 
  Ledge 
  and 
  Warden 
  Point, 
  stretching 
  

   away 
  towards 
  Hurst 
  Castle. 
  Indeed 
  the 
  lower 
  part 
  of 
  this 
  series 
  

   can 
  be 
  traced 
  continuously 
  all 
  through 
  Totland 
  Bay. 
  It 
  is 
  true 
  

   that 
  in 
  Warden 
  Cliff 
  the 
  beds 
  are 
  generally 
  of 
  a 
  more 
  arenaceous 
  

   character, 
  and 
  the 
  limestone 
  bands 
  are 
  thinner 
  and 
  in 
  most 
  cases 
  

   more 
  inconstant 
  than 
  at 
  Headon 
  Hill 
  ; 
  but 
  the 
  series 
  does 
  not 
  differ 
  

   more 
  at 
  these 
  two 
  localities 
  than 
  it 
  does 
  in 
  its 
  course 
  through 
  Headon 
  

   Hill, 
  and 
  the 
  same 
  species 
  of 
  freshwater 
  Mollusca 
  abound 
  in 
  both. 
  

   Further, 
  the 
  Upper 
  Limestone, 
  that 
  of 
  How 
  Ledge, 
  is 
  seen 
  to 
  greatly 
  

   increase 
  in 
  thickness 
  as 
  we 
  trace 
  it 
  in 
  the 
  direction 
  of 
  Headon 
  Hill, 
  

   and 
  the 
  sandy 
  beds 
  to 
  become 
  more 
  calcareous. 
  

  

  Now, 
  it 
  has 
  appeared 
  to 
  myself 
  and 
  other 
  geologists 
  that 
  this 
  

   well-marked 
  mass 
  of 
  strata, 
  which 
  can 
  certainly 
  be 
  traced 
  without 
  

   interruption 
  through 
  the 
  whole 
  of 
  the 
  Headon-Hill 
  section, 
  ought 
  to 
  

   be 
  found 
  in 
  the 
  Colwell-Bay 
  section 
  ; 
  but, 
  according 
  to 
  the 
  interpre- 
  

   tation 
  of 
  Messrs. 
  Keeping 
  and 
  Tawney, 
  it 
  there 
  thins 
  away 
  to 
  an 
  

   insignificant 
  nodular 
  band 
  not 
  above 
  1 
  foot 
  4 
  inches 
  thick 
  *. 
  

  

  But 
  if 
  the 
  Headon-Hill 
  limestone 
  series 
  be 
  identified 
  with 
  that 
  

   of 
  Warden 
  Point, 
  it 
  is 
  clear 
  that 
  the 
  brackish-water 
  beds 
  of 
  Colwell 
  

   Bay 
  overlying 
  these 
  limestones 
  cannot 
  be 
  identical 
  with 
  those 
  of 
  

   Headon 
  Hill, 
  which 
  underlie 
  the 
  limestones 
  — 
  a 
  correlation 
  which 
  

   my 
  critics 
  so 
  positively 
  affirm. 
  

  

  The 
  position 
  which 
  they 
  take 
  up 
  is 
  as 
  follows 
  : 
  — 
  Rejecting 
  the 
  

   identification 
  of 
  the 
  beds 
  at 
  Warden 
  Point 
  and 
  Headon 
  Hill 
  f, 
  they 
  

   proceed 
  to 
  indicate 
  what 
  they 
  believe 
  to 
  be 
  a 
  surer 
  means 
  of 
  corre- 
  

   lation 
  between 
  the 
  Colwell-Bay 
  and 
  Headon-Hill 
  sections. 
  

  

  At 
  the 
  east 
  end 
  of 
  Headon 
  Hill, 
  a 
  little 
  above 
  Widdick 
  Chine, 
  the 
  

   authors 
  find 
  a 
  series 
  of 
  brackish-water 
  beds, 
  which 
  they 
  profess 
  

   themselves 
  to 
  be 
  able 
  to 
  identify, 
  without 
  the 
  smallest 
  possibility 
  of 
  

   error, 
  with 
  the 
  well-known 
  brackish-water 
  beds 
  of 
  Colwell 
  Bay. 
  

   More 
  than 
  this, 
  they 
  assert 
  that 
  the 
  series 
  of 
  beds 
  at 
  these 
  two 
  

  

  * 
  These 
  authors 
  (loc. 
  cit. 
  p. 
  90) 
  have 
  endeavoured 
  to 
  establish 
  a 
  curious 
  tit 
  

   quoque 
  argument. 
  They 
  say 
  that 
  if 
  they 
  make 
  a 
  limestone 
  27 
  feet 
  in 
  thickness 
  

   thin 
  out 
  to 
  1 
  foot 
  8 
  inches 
  in 
  a 
  distance 
  of 
  1 
  mile 
  92B 
  yards, 
  I 
  have 
  made 
  the 
  

   same 
  bed 
  thin 
  out 
  to 
  5 
  feet, 
  and 
  ultimately 
  to 
  3 
  feet, 
  in 
  a 
  distance 
  of 
  \\ 
  mile. 
  

   But 
  in 
  this, 
  as 
  in 
  many 
  other 
  points, 
  my 
  critics 
  have 
  quite 
  misunderstood 
  my 
  

   views 
  ; 
  for 
  I 
  have 
  not 
  identified 
  the 
  How-Ledge 
  limestone, 
  but 
  the 
  whole 
  mass 
  

   of 
  limestones 
  and 
  sands 
  of 
  Warden 
  Point, 
  with 
  the 
  similar 
  series 
  in 
  Headon 
  Hill. 
  

  

  t 
  The 
  officers 
  of 
  the 
  Geological 
  Survey 
  have, 
  in 
  their 
  memoir 
  ' 
  On 
  the 
  Tertiary 
  

   Fluvio 
  marine 
  Formation 
  in 
  the 
  Isle 
  of 
  Wight' 
  (p. 
  132), 
  and 
  in 
  their 
  general 
  

   memoir 
  'On 
  the 
  Geology 
  of 
  the 
  Isle 
  of 
  Wight' 
  (p. 
  62), 
  deliberately 
  expressed 
  

   their 
  opinion 
  that 
  the 
  correlation 
  of 
  the 
  limestones 
  at 
  Warden 
  Point 
  and 
  

   Headon 
  Hill 
  is 
  the 
  true 
  one. 
  Messrs. 
  Keeping 
  and 
  Tawney 
  state 
  these 
  repeated 
  

   observations 
  to 
  be 
  "an 
  oversight 
  or 
  clerical 
  error." 
  Dr. 
  Wright's 
  equally 
  dis- 
  

   tinct 
  statement 
  they 
  in 
  the 
  same 
  way 
  characterize 
  as 
  " 
  a 
  mistake." 
  The 
  fact 
  is, 
  

   that 
  the 
  officers 
  of 
  the 
  Geological 
  Survey 
  have 
  expressed 
  in 
  their 
  different 
  

   writings 
  three 
  quite 
  irreconcilable 
  views. 
  I 
  have 
  adopted 
  one 
  of 
  these, 
  Messrs. 
  

   Keeping 
  and 
  Tawney 
  another 
  ; 
  but 
  I 
  am 
  quite 
  at 
  a 
  loss 
  to 
  understand 
  the 
  

   grounds 
  on 
  which 
  these 
  authors 
  claim 
  to 
  be 
  regarded 
  as 
  the 
  defenders 
  of 
  legi- 
  

   timate 
  authority. 
  

  

  