﻿676 
  SEARLES 
  V. 
  WOOD 
  ON 
  THE 
  NEWER 
  

  

  The 
  land, 
  as 
  a 
  whole, 
  stood 
  no 
  higher 
  (and 
  in 
  the 
  west 
  and 
  north- 
  

   west 
  probably 
  lower 
  than 
  now 
  : 
  but 
  the 
  fall 
  of 
  the 
  eastern 
  rivers 
  

   was 
  longer 
  and 
  natter 
  than 
  at 
  the 
  present 
  day, 
  and 
  in 
  that 
  posi- 
  

   tion, 
  by 
  the 
  depression 
  which 
  I 
  shall 
  trace 
  in 
  Stage 
  VI. 
  as 
  having 
  

   brought 
  in 
  the 
  sea 
  around 
  the 
  Wash, 
  their 
  water-level 
  was 
  raised 
  : 
  

   so 
  that, 
  in 
  some 
  places 
  near 
  their 
  entry 
  to 
  the 
  sea, 
  the 
  freshwater 
  

   deposits 
  of 
  some 
  of 
  these 
  rivers 
  which 
  flow 
  eastwards 
  pass 
  up 
  into 
  

   beds 
  containing 
  marine 
  shells 
  intermingled 
  with 
  fluviatile, 
  while 
  

   nevertheless, 
  as 
  at 
  Clacton, 
  these 
  freshwater 
  deposits 
  are 
  actually 
  

   overflowed 
  by 
  the 
  present 
  Xorth 
  Sea. 
  Before 
  describing 
  these, 
  however, 
  

   it 
  is 
  necessary 
  to 
  trace 
  more 
  precisely 
  the 
  progress 
  of 
  the 
  emergence 
  

   of 
  the 
  valley 
  of 
  the 
  Thames, 
  and 
  of 
  the 
  parts 
  connected 
  with 
  it. 
  

  

  In 
  the 
  first 
  portion 
  of 
  this 
  memoir 
  I 
  said 
  that 
  the 
  gravel 
  / 
  of 
  my 
  

   figures, 
  though 
  called 
  " 
  gravel 
  of 
  the 
  Thames 
  valley" 
  is 
  of 
  Glacial 
  

   age, 
  and 
  demanded 
  a 
  special 
  examination. 
  It 
  has 
  been 
  regarded 
  by 
  

   geologists 
  as 
  a 
  deposit 
  of 
  the 
  Thames 
  river 
  when 
  this 
  had 
  not 
  ex- 
  

   cavated 
  the 
  valley 
  in 
  which 
  it 
  runs 
  below 
  the 
  level 
  at 
  which 
  such 
  

   gravel 
  occurs 
  * 
  ; 
  but 
  in 
  my 
  view 
  this 
  gravel, 
  except 
  to 
  the 
  extent 
  

   that 
  it 
  has 
  become 
  mixed 
  up 
  with 
  the 
  Cymia-formation, 
  has 
  no 
  

   more 
  connexion 
  with 
  the 
  Thames 
  than 
  it 
  has 
  with 
  the 
  Severn, 
  its 
  

   relation 
  to 
  both 
  those 
  rivers 
  being 
  the 
  same 
  ; 
  for 
  it 
  accumulated 
  

   beneath 
  the 
  sea 
  when 
  the 
  valleys 
  of 
  both, 
  and 
  probably 
  the 
  lowest 
  

   of 
  the 
  partings 
  between 
  them 
  also, 
  were 
  submerged 
  (see 
  Map 
  6). 
  

   In 
  distinguishing 
  it 
  by 
  the 
  letter 
  /, 
  I 
  do 
  not 
  mean 
  to 
  imply 
  that 
  it 
  

   is 
  all 
  of 
  later 
  origin 
  than 
  that 
  marked 
  c 
  or 
  e, 
  or 
  even 
  than 
  that 
  of 
  

   maximum 
  submergence 
  (&'), 
  but 
  only 
  that 
  it 
  emerged 
  later. 
  Its 
  

   bottom 
  layers 
  might 
  indeed, 
  unless 
  there 
  was 
  a 
  destruction 
  and 
  re- 
  

   accumulation 
  of 
  the 
  gravel-material 
  by 
  tidal 
  movement 
  during 
  the 
  

   emergence, 
  represent 
  gravel 
  even 
  older 
  than 
  that 
  of 
  maximum 
  sub- 
  

   mergence, 
  since 
  the 
  lower 
  grounds 
  must 
  have 
  become 
  submerged 
  

   and 
  received 
  a 
  deposit 
  of 
  sand 
  and 
  gravel 
  before 
  the 
  higher 
  ; 
  but 
  as 
  

   in 
  that 
  part 
  of 
  it 
  which 
  occupies 
  East 
  Essex 
  there 
  occur 
  abundantly 
  

   fragments 
  of 
  stone 
  from 
  the 
  Weald 
  which 
  I 
  have 
  not 
  only 
  never 
  

   detected 
  in 
  the 
  gravels 
  b\ 
  c, 
  or 
  e, 
  but 
  which, 
  according 
  to 
  the 
  pro- 
  

   gress 
  of 
  the 
  emergence 
  of 
  the 
  south 
  of 
  England 
  traced 
  in 
  the 
  sequel, 
  

   could 
  not 
  have 
  been 
  brought 
  by 
  rivers 
  from 
  the 
  Weald 
  until 
  after 
  

   the 
  stage 
  in 
  that 
  progress 
  when 
  the 
  retreat 
  of 
  the 
  ice 
  of 
  the 
  Chalky 
  

   Clay 
  began, 
  it 
  is 
  probable 
  that 
  such 
  destruction 
  and 
  re-accumulation 
  

   did 
  go 
  on, 
  especially 
  since 
  we 
  get 
  no 
  such 
  thick 
  accumulation 
  of 
  

   this 
  gravel 
  as 
  is 
  found 
  in 
  the 
  case 
  of 
  the 
  gravel 
  of 
  the 
  Severn 
  area, 
  

   which 
  at 
  Mickleton 
  (where 
  it 
  represents 
  V 
  and 
  c) 
  is 
  80 
  feet 
  thick, 
  

   whereas 
  this 
  of 
  the 
  Thames 
  valley 
  rarely 
  exceeds, 
  and 
  seldom 
  reaches, 
  

   a 
  thickness 
  of 
  20 
  feet. 
  These 
  fragments, 
  which 
  seem 
  to 
  be 
  of 
  the 
  

   Kentish 
  Hagstone, 
  are 
  deeply 
  pitted 
  externally, 
  and, 
  though 
  small 
  

   and 
  much 
  worn, 
  are 
  thus 
  identifiable 
  with 
  larger 
  and 
  more 
  angular 
  

   fragments 
  similarly 
  pitted 
  which 
  are 
  strewed 
  over 
  the 
  Lower 
  Green- 
  

   sand 
  heights 
  around 
  Maidstone, 
  up 
  to 
  elevations 
  exceeding 
  300 
  feet, 
  

   and 
  form 
  the 
  chief 
  constituent 
  of 
  the 
  gravels 
  of 
  the 
  valley 
  of 
  the 
  

  

  * 
  Spurrell, 
  Quart. 
  Journ 
  Geol. 
  Soc. 
  vol. 
  xxxvi. 
  p. 
  546. 
  

  

  