﻿476 
  PEOP. 
  J. 
  W. 
  JTJDD 
  ON 
  THE 
  EOCENE 
  AND 
  OLIGOCENE 
  

  

  by 
  a 
  deposit 
  of 
  most 
  unmistakably 
  marine 
  origin 
  having 
  a 
  thickness 
  

   of 
  nearly 
  100 
  feet. 
  So 
  far 
  as 
  I 
  have 
  been 
  able 
  to 
  discover, 
  there 
  is 
  

   no 
  appearance 
  whatever 
  of 
  a 
  gradual 
  passage 
  between 
  these 
  fresh- 
  

   water 
  and 
  marine 
  series 
  of 
  beds, 
  the 
  lowest 
  portion 
  of 
  the 
  

   latter 
  abounding 
  in 
  marine 
  Mollusca, 
  Bryozoa, 
  and 
  even 
  Corals. 
  The 
  

   break 
  between 
  the 
  Headon 
  and 
  Brockenhurst 
  beds 
  appears 
  to 
  be 
  

   a 
  complete 
  one. 
  

  

  Messrs. 
  Keeping 
  and 
  Tawney 
  state 
  that 
  they 
  found 
  this 
  marine 
  

   series 
  to 
  lie 
  upon 
  an 
  eroded 
  surface 
  of 
  the 
  underlying 
  Headon 
  beds*. 
  

   This 
  fact 
  is 
  in 
  marked 
  agreement 
  with 
  the 
  sudden 
  change 
  in 
  the 
  

   nature 
  of 
  the 
  fauna. 
  At 
  Roydon 
  I 
  have 
  found 
  an 
  equally 
  abrupt 
  

   transition 
  from 
  the 
  freshwater 
  beds 
  of 
  the 
  Headon 
  to 
  the 
  marine 
  

   ones 
  of 
  the 
  Brockenhurst. 
  

  

  The 
  lowest 
  15 
  feet 
  of 
  these 
  beds, 
  which 
  are 
  of 
  an 
  argillaceous 
  cha- 
  

   racter, 
  contain 
  the 
  most 
  numerous 
  fossils 
  ; 
  and 
  these 
  can 
  be 
  collected 
  

   in 
  great 
  numbers 
  at 
  low 
  water 
  during 
  spring 
  tides. 
  In 
  the 
  suc- 
  

   ceeding 
  45 
  feet 
  of 
  strata, 
  which 
  are 
  of 
  a 
  sandy 
  nature, 
  marine 
  fossils 
  

   (and 
  only 
  marine 
  fossils) 
  arc 
  found, 
  and 
  such 
  species 
  as 
  occur 
  agree 
  

   entirely 
  with 
  those 
  found 
  in 
  the 
  underlying 
  argillaceous 
  beds. 
  The 
  

   highest 
  beds 
  consist 
  of 
  sands 
  and 
  clays 
  40 
  feet 
  in 
  thickness, 
  in 
  which 
  

   marine 
  fossils 
  become 
  more 
  numerous 
  ; 
  at 
  the 
  top 
  of 
  the 
  series 
  there 
  

   is 
  an 
  admixture 
  of 
  marine 
  and 
  freshwater 
  forms, 
  indicating 
  a 
  gradual 
  

   passage 
  into 
  the 
  overlying 
  freshwater 
  beds. 
  

  

  Now, 
  with 
  regard 
  to 
  the 
  age 
  of 
  this 
  marine 
  series 
  there 
  is 
  fortu- 
  

   nately 
  no 
  room 
  for 
  doubt. 
  There 
  occurs 
  in 
  the 
  New 
  Forest 
  a 
  series 
  

   of 
  marine 
  strata 
  which 
  Yon 
  Konen, 
  Duncan, 
  and 
  after 
  them 
  many 
  

   other 
  authors 
  have 
  identified 
  with 
  the 
  Tongrian 
  of 
  Belgium 
  and 
  the 
  

   Lower 
  Oligocene 
  of 
  Northern 
  Germany. 
  The 
  identity 
  of 
  the 
  fauna 
  

   found 
  in 
  this 
  marine 
  series 
  of 
  Whitecliff 
  Bay 
  with 
  that 
  found 
  in 
  the 
  

   New-Forest 
  bed 
  has 
  been 
  pointed 
  out 
  by 
  the 
  Rev. 
  0. 
  Fisher, 
  Messrs. 
  

   Codrington 
  and 
  Jenkins, 
  and 
  has 
  been 
  amply 
  confirmed 
  by 
  the 
  col- 
  

   lections 
  made 
  by 
  Messrs. 
  Keeping 
  and 
  Tawney. 
  

  

  This 
  continuous 
  marine 
  series 
  of 
  Whitecliff 
  Bay 
  Messrs. 
  Keeping 
  

   and 
  Tawney 
  propose 
  to 
  break 
  up 
  into 
  four 
  divisions. 
  To 
  the 
  lowest 
  

   two 
  feet 
  they 
  give 
  the 
  name 
  of 
  " 
  the 
  Brockenhurst 
  zone 
  ;" 
  and 
  the 
  

   next 
  12 
  feet 
  they 
  call 
  " 
  the 
  Hoy 
  don 
  zone." 
  These 
  two 
  divisions 
  

   they 
  unite 
  to 
  form 
  the 
  ' 
  : 
  Brockenhurst 
  beds." 
  The 
  next 
  division, 
  

   " 
  the 
  /SVmf/^«?^oZ«^^7t-sand, 
  , 
  ' 
  42 
  feet 
  thick, 
  they 
  admit 
  contains 
  a 
  

   number 
  of 
  distinctive 
  Brockenhurst 
  forms 
  ; 
  but 
  the 
  highest 
  division, 
  

   15 
  feet 
  thick, 
  they 
  follow 
  the 
  Geological 
  Survey 
  in 
  calling 
  " 
  the 
  

   Venns-'bed 
  :" 
  and 
  the 
  whole 
  marine 
  series, 
  including 
  the 
  overlying 
  19 
  

   feet 
  of 
  sands, 
  they 
  group 
  as 
  the 
  Middle 
  Headon. 
  

  

  According 
  to 
  the 
  view 
  propounded 
  by 
  those 
  authors 
  the 
  Brocken- 
  

   hurst 
  zone 
  is 
  a 
  thin, 
  highly 
  fossiliferous 
  deposit, 
  2 
  feet 
  thick 
  at 
  

   Whitecliff 
  Bay, 
  and 
  varying 
  from 
  a 
  few 
  inches 
  to 
  a 
  foot 
  in 
  thickness 
  

   at 
  the 
  Brockenhurst 
  cutting. 
  Yet 
  at 
  Roydon 
  brickyard, 
  less 
  than 
  

   two 
  miles 
  away 
  from 
  Brockenhurst, 
  this 
  zone 
  is 
  stated 
  to 
  be 
  altogether 
  

   absent, 
  nor 
  could 
  any 
  trace 
  of 
  it 
  be 
  found 
  at 
  Hordwell, 
  Headon. 
  or 
  

  

  * 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xxxvii. 
  (1881) 
  p. 
  109. 
  

  

  