﻿PLIOCENE 
  PERIOD 
  IN 
  ENGLAND. 
  705 
  

  

  Foreland*, 
  at 
  Portland 
  f 
  , 
  and 
  at 
  Sili 
  Bay 
  in 
  South 
  Wales 
  J. 
  Gravel 
  

   and 
  sand 
  is 
  spread 
  over 
  the 
  low 
  ground 
  which, 
  beginning 
  at 
  Brighton, 
  

   extends 
  westwards 
  over 
  a 
  gradually 
  widening 
  area 
  between 
  the 
  

   coast 
  and 
  the 
  South 
  Downs, 
  in 
  Sheet 
  9, 
  into 
  apparent 
  inosculation 
  

   with 
  the 
  gravel 
  at 
  a 
  nearly 
  corresponding 
  level 
  which 
  occurs 
  through 
  

   the 
  south 
  of 
  Sheets 
  11 
  and 
  15, 
  and 
  to 
  which 
  I 
  have 
  already 
  adverted 
  

   in 
  connexion 
  with 
  the 
  Bournemouth 
  plateau 
  in 
  tracing 
  the 
  emergence 
  

   from 
  the 
  great 
  depression 
  (see 
  ante, 
  p. 
  688). 
  This 
  sand, 
  in 
  which 
  he 
  

   found 
  marine 
  shells, 
  an 
  Echinoderm, 
  a 
  Cirriped, 
  and 
  some 
  Eorami- 
  

   nifera, 
  all 
  of 
  species 
  living 
  in 
  the 
  British 
  Channel, 
  Mr. 
  Prestwich 
  has 
  

   regarded 
  as 
  of 
  the 
  age 
  of 
  the 
  Brighton 
  beach 
  § 
  ; 
  but 
  as 
  the 
  places 
  where 
  

   he 
  describes 
  it, 
  viz. 
  Avisford 
  and 
  Bourne 
  Common 
  (from 
  the 
  former 
  of 
  

   which 
  he 
  obtained 
  these 
  organic 
  remains), 
  are 
  respectively, 
  he 
  says, 
  

   at 
  100 
  and 
  140 
  feet 
  elevation 
  above 
  0. 
  D., 
  and 
  the 
  Brighton 
  beach 
  

   is 
  only 
  from 
  10 
  to 
  12 
  feet 
  above 
  the 
  existing 
  one||, 
  I 
  fail 
  to 
  see 
  this, 
  

   especially 
  as 
  these 
  places 
  are 
  about 
  midway 
  between 
  that 
  beach 
  and 
  

   the 
  one 
  at 
  the 
  Eoreland 
  or 
  Eastern 
  end 
  of 
  the 
  Isle 
  of 
  Wight, 
  

   described 
  by 
  Mr. 
  Codrington 
  (and 
  shown 
  in 
  fig. 
  LV., 
  copied 
  from 
  

   his 
  figure), 
  where 
  the 
  top 
  of 
  the 
  shingle 
  at 
  the 
  cliffs' 
  base 
  is 
  at 
  

   only 
  60 
  feet 
  above 
  0. 
  D. 
  %. 
  All 
  these 
  beaches 
  appear 
  to 
  me 
  to 
  have 
  

   been 
  formed 
  during 
  a 
  pause 
  in 
  the 
  rise 
  from 
  the 
  depression 
  I 
  have 
  

   been 
  tracing, 
  when 
  the 
  land 
  became 
  stationary, 
  and 
  the 
  gravel 
  g 
  

   described 
  in 
  Stage 
  VII. 
  accumulated 
  ; 
  for 
  it 
  seems 
  to 
  me 
  an 
  impossi- 
  

   bility 
  that 
  cliffs 
  in 
  yielding 
  strata, 
  such 
  as 
  the 
  chalk 
  of 
  the 
  

   Brighton 
  one, 
  or 
  the 
  marl 
  of 
  the 
  Eoreland 
  one, 
  can 
  survive 
  a 
  sub- 
  

   mergence 
  — 
  the 
  action 
  of 
  the 
  sea 
  during 
  which 
  must 
  inevitably 
  be 
  to 
  

   plane 
  them 
  off 
  ; 
  while 
  during 
  emergence 
  cliffs 
  cannot 
  form, 
  because 
  

   the 
  sea 
  is 
  receding. 
  It 
  is 
  therefore 
  only 
  at 
  the 
  upper 
  limit 
  of 
  a 
  

   submergence, 
  or 
  during 
  a 
  stationary 
  period, 
  that 
  such 
  cliffs 
  can 
  be 
  

   formed 
  ; 
  and 
  these, 
  unless 
  protected 
  (as 
  the 
  cliffs 
  in 
  question 
  have 
  

   been 
  by 
  becoming 
  buried 
  under 
  a 
  peculiar 
  formation), 
  would 
  be 
  soon 
  

   obliterated 
  by 
  atmospheric 
  agency. 
  Thus, 
  I 
  think, 
  we 
  may 
  conclude 
  

   that 
  the 
  South 
  of 
  Englandhas 
  never 
  been 
  submerged 
  since 
  the 
  Brighton 
  

   and 
  Eoreland 
  beaches 
  were 
  formed, 
  unless 
  it 
  were 
  after 
  they 
  re- 
  

   ceived 
  the 
  envelope 
  of 
  materials 
  under 
  which 
  they 
  are 
  buried, 
  which 
  

   is 
  not 
  applicable 
  to 
  the 
  present 
  contention, 
  or 
  even 
  suggested. 
  

  

  It 
  was 
  before 
  these 
  beaches 
  came 
  into 
  existence 
  that 
  the 
  Avisford 
  

   and 
  Bourne-Common 
  sands 
  were, 
  in 
  my 
  opinion, 
  accumulated 
  up 
  to 
  

   elevations 
  of 
  110 
  feet; 
  and 
  these 
  appear 
  to 
  me 
  to 
  indicate 
  the 
  sub- 
  

   mergence 
  of 
  the 
  South 
  Coast 
  during 
  the 
  Cymia-formation, 
  though 
  

   I 
  cannot 
  point 
  to 
  any 
  actual 
  evidence 
  of 
  v^-submergence 
  connected 
  

   with 
  them, 
  or 
  to 
  the 
  presence 
  of 
  the 
  Cyrena 
  in 
  them. 
  

  

  * 
  By 
  Codrington, 
  in 
  vol. 
  xxvi. 
  p. 
  541, 
  of 
  whose 
  section 
  fig. 
  LV. 
  is 
  a 
  copy. 
  

  

  t 
  By 
  Prestwich, 
  in 
  vol. 
  xxxi. 
  p. 
  36. 
  

  

  I 
  By 
  same, 
  in 
  Brit. 
  Association 
  Reports 
  for 
  1880, 
  p. 
  581. 
  

  

  § 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xv. 
  p. 
  219. 
  

  

  || 
  Ibid. 
  p. 
  220, 
  and 
  vol. 
  xxviii. 
  p. 
  38. 
  

  

  *[ 
  Avisford 
  is 
  in 
  the 
  south-centre 
  of 
  Sheet 
  0, 
  20 
  miles 
  west 
  of 
  Brighton, 
  and 
  

   23 
  E.N.E. 
  of 
  the 
  Isle 
  of 
  Wight 
  Foreland 
  ; 
  and 
  Bourne 
  Common 
  is 
  due 
  west 
  of 
  

   this, 
  and 
  on 
  the 
  division 
  of 
  Sheets 
  9 
  and 
  10, 
  33 
  miles 
  west 
  of 
  Brighton 
  and 
  14 
  

   north-east 
  of 
  the 
  Foreland. 
  

  

  