﻿PLIOCENE 
  PERIOD 
  IN 
  ENGLAND. 
  723 
  

  

  the 
  minor 
  glaciation 
  (a 
  of 
  Mr. 
  Trimmer's 
  section, 
  and 
  called 
  by 
  him 
  

   the 
  Warp). 
  Just 
  as 
  the 
  splintered 
  flints 
  in 
  the 
  brickearth 
  which 
  

   overlies 
  the 
  Avisford 
  sand, 
  in 
  that 
  which 
  overlies 
  the 
  buried 
  cliff 
  at 
  

   the 
  Isle 
  of 
  Wight 
  Foreland, 
  shown 
  in 
  fig. 
  LV., 
  and 
  in 
  the 
  corresponding 
  

   material 
  which 
  overlies 
  the 
  buried 
  cliffs 
  of 
  Sangatte 
  and 
  Brighton, 
  

   cannot 
  have 
  been 
  derived 
  from 
  atmospheric 
  action 
  upon 
  the 
  formation 
  

   on 
  which 
  they 
  rest, 
  but 
  must 
  have 
  travelled 
  for 
  some 
  distance 
  over 
  

   the 
  surface, 
  so 
  have 
  the 
  flints 
  which 
  Mr. 
  Trimmer 
  thus 
  represents 
  as 
  

   occurring 
  in 
  this 
  overlying 
  " 
  warp 
  " 
  * 
  come 
  either 
  from 
  the 
  chalk 
  

   surface 
  which 
  occurs 
  at 
  some 
  distance 
  from 
  the 
  section, 
  or 
  from 
  

   the 
  Till 
  which, 
  though 
  shown 
  in 
  the 
  section 
  as 
  underlying 
  the 
  

   freshwater 
  beds 
  d, 
  e, 
  and 
  /, 
  forms 
  the 
  surface 
  at 
  some 
  distance, 
  

   and 
  not 
  from 
  any 
  action 
  upon 
  these 
  subjacent 
  beds 
  c/, 
  e, 
  and 
  /, 
  

   which 
  do 
  not 
  contain 
  such 
  flints. 
  

  

  In 
  his 
  diagram 
  section 
  of 
  the 
  beds 
  in 
  the 
  Selsea 
  peninsula, 
  

   which 
  I 
  have 
  given 
  at 
  p. 
  708, 
  Mr. 
  Godwin-Austen 
  shows 
  the 
  shingle 
  

   and 
  gravel 
  overlying 
  the 
  clay-gravel 
  with 
  large 
  hypersthene-rock 
  

   blocks, 
  as 
  overlain 
  by 
  this 
  brickearth 
  with 
  splinters 
  of 
  flint, 
  and 
  

   this, 
  he 
  says, 
  overlies 
  all 
  the 
  gravel 
  and 
  other 
  beds 
  of 
  the 
  Sussex 
  

   levels. 
  In 
  this 
  shingle, 
  clay-gravel, 
  and 
  overlying 
  brickearth 
  we 
  

   find 
  the 
  exact 
  parallel 
  of 
  the 
  buried 
  cliffs, 
  thus. 
  

  

  The 
  shingle 
  at 
  the 
  Brighton 
  cliff 
  is, 
  according 
  to 
  Mr. 
  Tylor, 
  10 
  

   feet 
  above 
  high-water 
  mark, 
  while 
  that 
  in 
  Mr. 
  Codrington's 
  figure 
  

   of 
  the 
  Isle 
  of 
  Wight 
  Foreland 
  (fig. 
  LV.) 
  has 
  its 
  upper 
  limit 
  at 
  about 
  

   60 
  and 
  its 
  base 
  about 
  20 
  feet 
  above 
  0. 
  D. 
  Selsea 
  is 
  nearer 
  to 
  the 
  

   latter 
  than 
  to 
  the 
  former 
  ; 
  and 
  if 
  we 
  take 
  the 
  upper 
  limit 
  of 
  the 
  

   shingle 
  as 
  representing 
  high-water 
  mark 
  of 
  spring 
  tides, 
  we 
  may 
  

   infer 
  that 
  at 
  the 
  date 
  of 
  these 
  beaches 
  the 
  mean 
  level 
  of 
  the 
  sea 
  

   over 
  the 
  Selsea 
  peninsula 
  was 
  about 
  40 
  feet 
  above 
  the 
  present. 
  Now 
  

   this 
  agrees 
  with 
  the 
  position 
  of 
  the 
  gravel 
  with 
  great 
  erratics, 
  the 
  

   elevation 
  of 
  which, 
  as 
  shown 
  in 
  fig. 
  XLII.f, 
  is 
  uniform 
  at 
  from 
  15 
  

   to 
  20 
  feet 
  above 
  0. 
  D., 
  which 
  would 
  give 
  a 
  mean 
  depth 
  of 
  from 
  25 
  

   to 
  30 
  feet 
  of 
  water 
  over 
  it 
  at 
  the 
  time 
  of 
  this 
  gravel. 
  

  

  It 
  seems 
  to 
  me 
  obvious 
  that 
  just 
  as 
  this 
  part 
  of 
  the 
  coast 
  is 
  a 
  

   flat 
  at 
  the 
  present 
  time 
  without 
  cliffs, 
  and 
  extends 
  from 
  opposite 
  the 
  

   eastern 
  end 
  of 
  the 
  Isle 
  of 
  Wight 
  (with 
  its 
  higher 
  ground, 
  and 
  con- 
  

   sequent 
  cliffs) 
  to 
  Brighton, 
  where 
  the 
  same 
  cliff 
  begins 
  again, 
  so 
  was 
  

   it 
  also 
  when 
  the 
  buried 
  cliffs 
  were 
  washed 
  by 
  the 
  sea 
  during 
  the 
  

   stage 
  under 
  consideration, 
  and 
  the 
  shingle 
  accumulated 
  at 
  their 
  feet 
  ; 
  

   the 
  mean 
  sea-level 
  at 
  Selsea 
  just 
  mentioned 
  allowing 
  the 
  floes 
  to 
  

  

  * 
  Mr. 
  Trimmer 
  referred 
  this 
  Warp 
  to 
  the 
  action 
  of 
  the 
  sea 
  during 
  the 
  last 
  

   geological 
  period, 
  contrary 
  to 
  my 
  view 
  of 
  its 
  origin.- 
  Mr. 
  O. 
  Fisher 
  lias 
  called 
  

   it 
  " 
  Trail," 
  and 
  referred 
  it 
  to 
  land-ice 
  agency 
  during 
  a 
  later 
  glaciation 
  than 
  the 
  

   main 
  one. 
  

  

  t 
  I 
  have 
  constructed 
  this 
  figure 
  from 
  Mr. 
  Codrington's 
  gravel 
  map 
  (pi. 
  xxxvi. 
  of 
  

   vol. 
  xxvi. 
  of 
  the 
  Journal), 
  and, 
  as 
  to 
  the 
  older 
  Tertiaries 
  on 
  which 
  these 
  gravels 
  

   rest, 
  from 
  the 
  Geological 
  Purvey 
  map. 
  It 
  shows 
  the 
  comparative 
  levels 
  which 
  

   this 
  gravel 
  of 
  the 
  minor 
  glaciation 
  and 
  that 
  of 
  the 
  major 
  respectively 
  occupy, 
  

   though 
  the 
  greatest 
  elevation 
  of 
  the 
  latter 
  in 
  the 
  section 
  (4l 
  ( 
  .> 
  feet) 
  is 
  260 
  feet 
  

   below 
  the 
  level 
  to 
  which 
  the 
  submergence 
  attained 
  in 
  this 
  part 
  during 
  the 
  

   major 
  glaciation. 
  

  

  