﻿JUEASSIC 
  CLAYS 
  OF 
  LINCOLNSHIRE. 
  

  

  553 
  

  

  shire, 
  are 
  found 
  in 
  both 
  localities. 
  Further, 
  the 
  fossils 
  of 
  the 
  clays 
  

   of 
  Worlaby 
  assign 
  them 
  to 
  a 
  higher 
  horizon 
  than 
  the 
  selenitiferous 
  

   clays. 
  

  

  From 
  the 
  above 
  observations 
  it 
  will 
  be 
  seen 
  that 
  the 
  selenitiferous 
  

   clays 
  are 
  succeeded 
  in 
  the 
  southern 
  part 
  of 
  the 
  district 
  under 
  con- 
  

   sideration 
  by 
  clays 
  containing 
  Ostrea 
  deltoidea 
  in 
  abundance 
  ; 
  whilst 
  

   further 
  north, 
  and 
  probably 
  at 
  a 
  slightly 
  higher 
  horizon, 
  there 
  

   occurs 
  a 
  band 
  of 
  clay 
  with 
  ironstone 
  concretions 
  and 
  iron-pyrites, 
  

   in 
  which 
  Amm. 
  decvpiens 
  is 
  fairly 
  common. 
  

  

  The 
  third 
  zone 
  includes 
  the 
  clays 
  in 
  the 
  pits 
  of 
  Baumber, 
  Langton, 
  

   Market 
  Rasen, 
  and 
  Holton-le-Moor 
  Station, 
  all 
  of 
  which 
  have 
  been 
  

   fully 
  described 
  by 
  Prof. 
  Blake 
  *. 
  There 
  is 
  but 
  little 
  to 
  add 
  to 
  his 
  

   account 
  of 
  these 
  sections. 
  The 
  clays 
  in 
  the 
  brickyard 
  \ 
  mile 
  west- 
  

   south-west 
  of 
  Hatton 
  (called 
  Langton 
  by 
  Prof. 
  Blake) 
  yielded 
  the 
  

   following 
  species 
  in 
  addition 
  to 
  those 
  recorded 
  by 
  him 
  : 
  — 
  

  

  Ammonites 
  decipiens, 
  Sow. 
  

   Cerithium 
  multiplicatum, 
  Blake. 
  

   Anomia, 
  sp. 
  

   Ostrea 
  gibbosa, 
  Les. 
  

  

  lseviuscula, 
  Sow. 
  

  

  Area 
  longipunctata, 
  Blake. 
  

  

  Pholadornya 
  acuticosta, 
  Sow. 
  

  

  Protei, 
  Ag. 
  

  

  Pholadidea 
  compressa, 
  Sow. 
  

   Cardium 
  striatulum, 
  Sow. 
  

   Corbula 
  fallax, 
  Cont. 
  

   Deshayesia, 
  Bnv. 
  

  

  The 
  fauna 
  of 
  the 
  clays 
  of 
  Langton 
  presents 
  a 
  close 
  affinity 
  with 
  

   that 
  of 
  Market 
  Rasen 
  and 
  also 
  of 
  Baumber. 
  Ammonites 
  alternans, 
  

   which 
  is 
  very 
  rare 
  in 
  the 
  clays 
  below, 
  is 
  very 
  common 
  in 
  this 
  zone, 
  

   and 
  may 
  be 
  regarded 
  as 
  its 
  characteristic 
  fossil. 
  The 
  fauna 
  is 
  much 
  

   richer 
  than 
  that 
  of 
  any 
  other 
  zones 
  of 
  the 
  Kimeridge 
  Clay, 
  over 
  

   50 
  species 
  being 
  recorded 
  from 
  the 
  above-mentioned 
  localities 
  alone. 
  

  

  The 
  fourth 
  and 
  uppermost 
  zone 
  of 
  these 
  clays 
  is 
  that 
  which 
  

   occurs 
  in 
  pits 
  near 
  Horncastle 
  t. 
  At 
  present 
  only 
  two 
  pits 
  are 
  open, 
  

   and 
  these 
  show 
  dark 
  clays 
  with 
  septarian 
  nodules. 
  These 
  clays 
  

   are 
  distinguished 
  from 
  those 
  of 
  the 
  underlying 
  zone 
  principally 
  by 
  

   the 
  absence 
  in 
  them 
  of 
  Amm. 
  alternans, 
  and 
  also 
  by 
  the 
  fossils 
  being 
  

   less 
  numerous 
  and 
  badly 
  preserved. 
  

  

  The 
  clays 
  occurring 
  between 
  the 
  Oxford 
  Clay 
  and 
  Upper 
  Kime- 
  

   ridge 
  in 
  Lincolnshire 
  may 
  be 
  divided 
  therefore 
  into 
  the 
  following 
  

   four 
  zones, 
  arranged 
  in 
  descending 
  order 
  : 
  — 
  

  

  4. 
  Clays 
  with 
  Lower 
  Kimeridge 
  fossils, 
  in 
  which 
  Amm. 
  alternans 
  

  

  is 
  absent. 
  

   3. 
  Clays 
  in 
  which 
  Amm. 
  alternans 
  is 
  common. 
  

   2. 
  Clays 
  crowded 
  with 
  Ostrea 
  deltoidea. 
  

   1. 
  Selenitiferous 
  clays 
  with 
  Ostrea 
  deltoidea 
  and 
  Gryphcea 
  

  

  dilatata. 
  

  

  Nearly 
  the 
  whole 
  of 
  these 
  four 
  zones 
  of 
  clays 
  has 
  been 
  mapped 
  by 
  

   Prof. 
  Blake 
  % 
  an 
  d 
  the 
  Geological 
  Survey 
  § 
  as 
  Lower 
  Kimeridge. 
  

   Prof. 
  Blake 
  subdivides 
  his 
  Lower 
  Kimeridge 
  of 
  Lincolnshire 
  into 
  

   six 
  zones, 
  but 
  his 
  arrangement 
  differs 
  somewhat 
  from 
  that 
  adopted 
  

   in 
  this 
  paper. 
  The 
  clays 
  in 
  the 
  cutting 
  east 
  of 
  Brigg 
  are 
  regarded 
  

  

  * 
  Op. 
  cit. 
  pp. 
  207, 
  208. 
  

   \ 
  Op. 
  cit. 
  p. 
  202. 
  

  

  t 
  Blake, 
  op. 
  cit. 
  p. 
  205. 
  

   § 
  Sheet 
  83. 
  

  

  