﻿PLIOCENE 
  TERIOD 
  IX 
  ENGLAND. 
  7 
  25 
  

  

  which 
  accumulated 
  g 
  of 
  the 
  Thames 
  valley, 
  took 
  place, 
  which 
  I 
  have 
  

   described 
  in 
  Stage 
  VI, 
  The 
  Ci/rena-gravel 
  of 
  the 
  Somme 
  valley 
  is 
  

   overlain 
  with 
  similar 
  loam 
  ; 
  and 
  in 
  the 
  ' 
  Geological 
  Magazine 
  ' 
  for 
  

   August 
  and 
  September 
  1882, 
  I 
  have 
  suggested 
  that 
  the 
  Loess 
  which 
  

   covers 
  so 
  much 
  of 
  the 
  Europaeo-Asiatic 
  and 
  North-American 
  con- 
  

   tinents, 
  through 
  latitudes 
  where, 
  during 
  the 
  glaciations, 
  the 
  soil 
  

   must 
  have 
  been 
  permanently 
  frozen, 
  but 
  where 
  there 
  was 
  no 
  land- 
  

   ice, 
  originated 
  from 
  the 
  action 
  here 
  described 
  by 
  me. 
  I 
  have 
  also 
  

   there 
  endeavoured 
  to 
  show, 
  in 
  more 
  detail 
  than 
  my 
  space 
  here 
  allows, 
  

   the 
  precise 
  way 
  in 
  which, 
  by 
  the 
  continuous 
  rupturing 
  of 
  the 
  flints 
  

   of 
  the 
  upper 
  chalk 
  by 
  the 
  intense 
  cold 
  on 
  the 
  unprotected 
  surface, 
  

   aud 
  by 
  the 
  lateral 
  escape 
  through 
  this 
  thawing 
  and 
  moving 
  

   surface-layer 
  of 
  the 
  water 
  with 
  which 
  it 
  was 
  saturated, 
  after 
  it 
  had 
  

   taken 
  up 
  the 
  chalk 
  by 
  solution, 
  the 
  loam 
  of 
  Picardy 
  with 
  

   angular 
  flint 
  fragments 
  arose 
  — 
  those 
  thicker 
  accumulations 
  of 
  it 
  

   which 
  occupy 
  the 
  parts 
  of 
  the 
  plateaux 
  above 
  the 
  level 
  to 
  which 
  the 
  

   submergence 
  of 
  the 
  major 
  glaciation 
  reached 
  having 
  originated 
  

   during 
  both 
  the 
  major 
  and 
  minor 
  glaciations 
  : 
  while 
  that 
  which 
  

   occurs 
  on 
  the 
  valley-sides 
  and 
  overspreads 
  the 
  Cymia-gravel 
  of 
  the 
  

   Somme, 
  and 
  is 
  of 
  much 
  less 
  thickness, 
  originated 
  during 
  the 
  minor 
  

   only 
  ; 
  these 
  valleys 
  having 
  been 
  filled 
  with 
  the 
  sea, 
  and 
  so 
  exempt 
  

   from 
  this 
  action, 
  during 
  the 
  major 
  glaciation. 
  

  

  Although 
  the 
  origin 
  of 
  the 
  material 
  with 
  fragments 
  and 
  splinters 
  

   thus 
  burying 
  the 
  cliffs 
  appears 
  to 
  me 
  of 
  this 
  nature, 
  and 
  the 
  position 
  

   it 
  occupies, 
  not 
  merely 
  in 
  relation 
  to 
  these 
  cliffs 
  but 
  also 
  in 
  the 
  

   general 
  sequence 
  of 
  events, 
  to 
  be 
  clear 
  and 
  consistent, 
  yet 
  Prof. 
  

   Prestwich 
  * 
  has 
  taken 
  views 
  so 
  contrary 
  to 
  those 
  at 
  which 
  I 
  have 
  

   arrived, 
  that 
  I 
  cannot 
  pass 
  from 
  the 
  subject 
  without 
  some 
  examina- 
  

   tion 
  of 
  them. 
  

  

  In 
  describing 
  the 
  features 
  connected 
  with 
  the 
  buried 
  cliffs 
  of 
  

   Portland 
  and 
  Sili 
  Bay, 
  and 
  other 
  localities 
  along 
  both 
  the 
  Prench 
  

   and 
  English 
  coasts 
  of 
  the 
  British 
  Channel, 
  he 
  attributes 
  the 
  origin 
  

   of 
  the 
  burying-material 
  to 
  a 
  great 
  submergence, 
  with 
  which 
  he 
  

   connects 
  the 
  destruction 
  of 
  Palaeolithic 
  man 
  and 
  of 
  some 
  of 
  the 
  

   great 
  Mammalia. 
  

  

  In 
  the 
  particular 
  case 
  at 
  Portland, 
  he 
  contends 
  that 
  this 
  submer- 
  

   gence 
  took 
  place 
  after 
  a 
  great 
  denudation 
  had 
  occurred 
  over 
  a 
  line 
  

   of 
  upthrow 
  similar 
  to 
  that 
  which 
  has 
  taken 
  place 
  to 
  the 
  south 
  of 
  the 
  

   gravel 
  crowning 
  Caesar's 
  Camp 
  Hill 
  in 
  figs. 
  II. 
  and 
  III., 
  and 
  Headon 
  

   Hill 
  in 
  figs. 
  IV. 
  and 
  V., 
  in 
  the 
  plate 
  accompanying 
  the 
  first 
  part 
  of 
  this 
  

   memoir 
  ; 
  and 
  in 
  his 
  sections 
  he 
  shows 
  this 
  upthrown 
  and 
  denuded 
  

   space 
  as 
  overlooked 
  by 
  gravel 
  formed 
  prior 
  to 
  this 
  upthrow, 
  and 
  

   crowning 
  the 
  chalk 
  escarpment, 
  just 
  as 
  the 
  correspondingly 
  upthrown 
  

   and 
  denuded 
  space 
  of 
  the 
  Weald 
  is 
  overlooked 
  by 
  the 
  gravel 
  of 
  

   Caesar's 
  Camp, 
  and 
  that 
  of 
  the 
  Isle 
  of 
  Wight 
  is 
  skirted 
  by 
  the 
  gravel 
  

   of 
  Headon 
  Hill 
  in 
  these 
  figures. 
  The 
  line 
  of 
  chalk 
  upthrow 
  connected 
  

   with 
  this 
  great 
  denudation 
  behind 
  Portland 
  is 
  a 
  part 
  of 
  that 
  of 
  

   the 
  Isle 
  of 
  Wight, 
  which 
  has 
  placed 
  the 
  Headon 
  gravel 
  in 
  the 
  

  

  * 
  See 
  the 
  papers 
  of 
  Prof. 
  Prestwich 
  already 
  cited, 
  and 
  another 
  in 
  British 
  

   Association 
  Proceedings 
  in 
  1880. 
  

  

  