﻿466 
  

  

  -ME. 
  S. 
  S. 
  BUCKMAN 
  ON 
  THE 
  

  

  80 
  far 
  I 
  can 
  speak 
  almost 
  entirely 
  from 
  my 
  own 
  knowledge 
  of 
  

   the 
  various 
  localities. 
  To 
  continue 
  the 
  subject 
  : 
  — 
  Dr. 
  AYright 
  * 
  

   notices 
  that 
  near 
  Burford, 
  and 
  in 
  the 
  north-eastern 
  parts 
  of 
  the 
  

   Northleach 
  district 
  of 
  the 
  Cotteswolds, 
  the 
  Pa 
  rkinsoni- 
  zone 
  rests 
  

   upon 
  the 
  Upper 
  Lias. 
  Mr. 
  Hudlestonf 
  says 
  that 
  further 
  east- 
  

   wards, 
  namely, 
  at 
  Hook 
  Norton, 
  in 
  Oxfordshire, 
  the 
  Parkinsoni-zone 
  

   rests 
  on 
  the 
  Murchisonce-zone 
  and 
  that 
  there 
  is 
  therefore 
  a 
  hiatus. 
  

  

  In 
  a 
  section 
  of 
  the 
  Northampton 
  district, 
  very 
  kindly 
  sent 
  to 
  me 
  

   by 
  Mr. 
  Thompson, 
  an 
  " 
  Unconformity 
  " 
  is 
  said 
  to 
  exist 
  between 
  the 
  

   Lower 
  Estuarine 
  series 
  (Northampton 
  Sand, 
  Murchisonce- 
  or 
  Opa- 
  

   linum-zone 
  ?) 
  and 
  the 
  Upper 
  Estuarine 
  series 
  (Great 
  Oolite). 
  

  

  At 
  Rockingham, 
  Stamford, 
  and 
  Grantham 
  Prof. 
  Judd 
  J 
  depicts 
  

   the 
  Upper 
  Estuarine 
  series 
  (Great 
  Oolite 
  1 
  resting 
  upon 
  the 
  Lincoln- 
  

   shire 
  Limestone 
  of 
  the 
  Inferior 
  Oolite. 
  In 
  Middle 
  and 
  North 
  Lin- 
  

   colnshire 
  he 
  shows 
  the 
  Great- 
  Oolite 
  Limestone 
  resting 
  on 
  the 
  

   Lincolnshire 
  Limestone. 
  Now 
  he 
  places 
  the 
  Lincolnshire 
  Limestone 
  

   in 
  the 
  Soiverbyi-zone, 
  but 
  at 
  the 
  same 
  time 
  on 
  the 
  level 
  of 
  the 
  

   "Oolite-Marl'' 
  (page 
  8). 
  In 
  the 
  latter 
  case, 
  the 
  Lincolnshire 
  

   Limestone 
  would 
  be 
  in 
  the 
  Murchisonce-zone, 
  according 
  to 
  my 
  views, 
  

   and 
  this 
  is 
  Mr. 
  Hudleston's 
  opinion 
  of 
  its 
  proper 
  position 
  {op. 
  cit. 
  

   p. 
  72). 
  Therefore 
  we 
  have 
  the 
  same 
  hiatus 
  at 
  the 
  top 
  of 
  the 
  

   Murchisonce-zone, 
  only 
  that 
  it 
  is 
  now 
  much 
  greater, 
  owing 
  to 
  the 
  

   absence 
  of 
  all 
  the 
  upper 
  beds 
  of 
  the 
  Inferior 
  Oolite. 
  

  

  In 
  the 
  Yorkshire 
  basin 
  we 
  have 
  the 
  Humphriesianum-zone 
  (Scar- 
  

   borough 
  Limestone) 
  resting 
  upon 
  the 
  Murchisonce-zone 
  (Hudleston, 
  

   op. 
  cit. 
  page 
  75), 
  so 
  that 
  here, 
  too, 
  we 
  have 
  a 
  palaeontological 
  hiatus 
  

   (the 
  Sauzei-zone 
  and 
  the 
  Concavum-beds 
  being 
  absent), 
  though 
  there 
  

   is 
  no 
  mention 
  of 
  any 
  lithological 
  one. 
  

  

  I 
  have 
  therefore 
  shown 
  that 
  over 
  nearly 
  the 
  whole 
  of 
  the 
  English 
  

   Inferior-Oolite 
  area, 
  and 
  especially 
  where 
  the 
  zones 
  can 
  best 
  be 
  

   distinguished, 
  there 
  already 
  exists 
  a 
  well-marked, 
  ready-made 
  line 
  

   of 
  division, 
  due 
  to 
  the 
  absence, 
  generally, 
  of 
  the 
  Humphriesianum- 
  

   zone, 
  but 
  very 
  often 
  to 
  the 
  absence 
  of 
  other 
  zones 
  also. 
  In 
  some 
  

   cases 
  this 
  hiatus 
  is 
  marked 
  stratigraphically 
  by 
  the 
  presence 
  of 
  a 
  

   bored 
  bed, 
  by 
  the 
  under 
  rock 
  being 
  pitted 
  or 
  covered 
  with 
  oysters, 
  

   and 
  by 
  other 
  signs 
  of 
  a 
  cessation 
  of 
  deposition 
  ; 
  but 
  in 
  other 
  cases 
  

   a 
  long 
  interval 
  may 
  not 
  be 
  marked 
  in 
  this 
  way, 
  and 
  the 
  two 
  periods 
  

   may 
  be 
  actually 
  cemented 
  together 
  into 
  one 
  stone 
  (see 
  page 
  447), 
  so 
  

   that 
  we 
  again 
  find 
  lithological 
  features 
  to 
  be 
  unreliable. 
  

  

  Dr. 
  Vacek, 
  who 
  has 
  worked 
  this 
  matter 
  out 
  very 
  extensively 
  in 
  

   connexion 
  with 
  his 
  proposal 
  to 
  include 
  the 
  Murchisonce-zone 
  in 
  the 
  

   Lias, 
  finds, 
  upon 
  the 
  continent, 
  a 
  very 
  extensive 
  hiatus 
  between 
  the 
  

   Murchisonce- 
  and 
  so-called 
  Sowerbyi-zones. 
  Possibly 
  this 
  Soiverbyi- 
  

   zone, 
  in 
  its 
  strict 
  sense, 
  is 
  more 
  correctly 
  on 
  the 
  horizon 
  of 
  our 
  Sauzei- 
  

   zone 
  ; 
  and 
  in 
  that 
  case 
  it 
  seems 
  to 
  me 
  that 
  our 
  Concavum-zone 
  is 
  

   possibly 
  the 
  stratum 
  the 
  absence 
  of 
  which 
  the 
  hiatus 
  represents. 
  

  

  Eugene 
  Deslongschamps 
  (op. 
  cit. 
  p. 
  94) 
  shows 
  that 
  this 
  hiatus, 
  

  

  * 
  " 
  Subdivisions 
  of 
  the 
  Inferior 
  Oolite," 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xvi. 
  p. 
  18 
  

   (1860). 
  

  

  t 
  "Gasteropoda 
  of 
  the 
  Inferior 
  Oolite," 
  Palceont. 
  Soc. 
  1887, 
  p. 
  71. 
  

  

  \ 
  Memoirs 
  of 
  Geological 
  Survey, 
  " 
  Geology 
  of 
  Eutland," 
  plate 
  i. 
  (vertical 
  

   sections). 
  

  

  