﻿692 
  SEARLES 
  V. 
  WOOD 
  ON 
  THE 
  NEWER 
  

  

  Part 
  2. 
  — 
  The 
  Post-glacial 
  Pertod, 
  comprising 
  the 
  Cyrena-flumi- 
  

   nalis 
  Formation, 
  and 
  the 
  Minor 
  Glaciation. 
  

  

  Stage 
  YL 
  The 
  GTKESA.-formation. 
  

  

  Under 
  the 
  conditions 
  which 
  I 
  have 
  traced, 
  the 
  valley 
  of 
  the 
  

   Thames, 
  after 
  the 
  parting 
  from 
  the 
  Severn 
  system 
  by 
  way 
  of 
  the 
  

   Swillbrook 
  had 
  emerged, 
  became 
  a 
  sea-loch 
  open 
  to 
  the 
  North 
  Sea 
  

   by 
  way 
  of 
  its 
  present 
  month, 
  and 
  also 
  open 
  to 
  the 
  Weald 
  by 
  way 
  

   of 
  the 
  low 
  ground 
  over 
  the 
  faulted 
  part 
  of 
  the 
  Chalk 
  near 
  Earnham. 
  

   The 
  partings 
  of 
  those 
  drainage-systems 
  of 
  the 
  Weald 
  which 
  are 
  re- 
  

   presented 
  as 
  covered 
  by 
  the 
  sea 
  in 
  Map 
  2, 
  being 
  most 
  of 
  them 
  equal 
  

   in 
  actual 
  elevation 
  to 
  that 
  of 
  the 
  Swillbrook, 
  and 
  even 
  the 
  lowest 
  of 
  

   them, 
  which 
  is 
  that 
  dividing 
  the 
  (Kentish) 
  Stour 
  from 
  Roinney 
  marsh 
  

   at 
  about 
  150 
  feet, 
  equal 
  to 
  it 
  when 
  taken 
  in 
  connexion 
  with 
  the 
  

   westerly 
  increment 
  of 
  depression, 
  had, 
  however, 
  at 
  this 
  time 
  all 
  

   emerged. 
  As 
  the 
  low 
  ground 
  of 
  this 
  faulted 
  chalk 
  emerged, 
  the 
  

   basin 
  of 
  the 
  Thames 
  became 
  separated 
  from 
  the 
  Weald, 
  except 
  

   to 
  the 
  extent 
  of 
  receiving 
  drainage 
  from 
  thence 
  as 
  it 
  now 
  does 
  by 
  

   the 
  Wcy, 
  Mole, 
  and 
  Darent 
  ; 
  from 
  which 
  condition, 
  as 
  emergence 
  

   proceeded, 
  it 
  passed 
  to 
  that 
  of 
  a 
  river 
  which 
  mingled 
  with 
  the 
  sea- 
  

   water 
  much 
  to 
  the 
  east 
  of 
  the 
  point 
  at 
  which 
  it 
  now 
  does 
  so, 
  receiving 
  

   probably 
  as 
  tributaries 
  the 
  rivers 
  of 
  North 
  Kent 
  and 
  South 
  Essex, 
  

   though 
  hardly, 
  I 
  think, 
  those 
  of 
  Suffolk 
  and 
  Norfolk, 
  which 
  probably 
  

   reached 
  the 
  sea 
  independently, 
  though 
  much 
  to 
  the 
  east 
  of 
  the 
  

   present 
  coast-line. 
  This 
  greater 
  distance 
  eastward 
  of 
  the 
  river- 
  

   discharge 
  at 
  the 
  commencement 
  of 
  the 
  Cyr 
  ena-form&tion 
  was 
  due 
  (if 
  

   we 
  omit 
  for 
  the 
  present 
  that 
  part 
  of 
  the 
  problem 
  which 
  involves 
  the 
  

   general 
  depression 
  of 
  England 
  subsequent 
  to 
  the 
  last 
  stage 
  traced 
  in 
  

   this 
  memoir, 
  and 
  which 
  has 
  caused 
  land-surfaces 
  round 
  our 
  coast 
  to 
  

   become 
  covered 
  with 
  salt 
  water 
  and 
  marine 
  silt 
  and 
  forest 
  with 
  marsh 
  

   mud, 
  and 
  which 
  has 
  brought 
  the 
  salt 
  water 
  further 
  up 
  the 
  Thames 
  

   than 
  we 
  find 
  any 
  certain 
  evidence 
  of 
  its 
  having 
  done 
  during 
  the 
  

   re-submergence 
  I 
  am 
  about 
  to 
  trace) 
  to 
  some 
  little 
  of 
  the 
  original 
  

   westerly 
  increment 
  of 
  depression 
  not 
  having 
  been 
  recovered 
  ; 
  or, 
  

   more 
  properly 
  speaking, 
  to 
  the 
  present 
  inclination 
  not 
  having 
  been 
  

   fully 
  attained 
  ; 
  for, 
  during 
  the 
  Red 
  Crag, 
  South 
  Essex 
  and 
  Kent 
  pro- 
  

   bably 
  extended 
  far 
  beyond 
  their 
  present 
  limit, 
  and 
  most 
  likely 
  to 
  

   Belgium 
  # 
  . 
  It 
  is 
  important, 
  in 
  considering 
  the 
  volume 
  of 
  fresh 
  water 
  

   within 
  the 
  Thames 
  valley 
  during 
  the 
  stage 
  under 
  consideration, 
  that 
  

   this 
  should 
  be 
  borne 
  in 
  mind, 
  as 
  well 
  as 
  the 
  position 
  occupied 
  by 
  

   the 
  bottom 
  of 
  the 
  river, 
  as 
  shown 
  by 
  the 
  basement 
  bed 
  (No. 
  1) 
  of 
  

  

  * 
  Prof. 
  Prestwich 
  describes 
  the 
  gravel 
  corresponding 
  with 
  the 
  sand 
  in 
  which 
  he 
  

   has 
  found 
  the 
  Cyrena 
  at 
  Oxford 
  as 
  occupying 
  a 
  level 
  of 
  from 
  20 
  to 
  25 
  feet 
  above 
  

   the 
  river 
  around 
  Oxford. 
  At 
  Grays 
  and 
  Crayford 
  the 
  fossiliferous 
  part 
  of 
  the 
  

   Cyrewa-sand 
  (No. 
  3 
  of 
  the 
  sect.) 
  reaches 
  to 
  about 
  50, 
  which 
  would 
  show 
  the 
  dif- 
  

   ference 
  in 
  fall 
  between 
  there 
  and 
  Oxford 
  to 
  be 
  about 
  25 
  feet 
  less 
  than 
  now. 
  As 
  

   the 
  Reindeer 
  occurs 
  in 
  some 
  of 
  the 
  Oxford 
  gravel, 
  the 
  gravel 
  g 
  with 
  Reindeer 
  

   remains 
  there 
  is 
  probably 
  at 
  the 
  same 
  level 
  with 
  the 
  Cyrena-szind. 
  

  

  

  