﻿PLIOCENE 
  PERIOD 
  IN 
  ENGLAND. 
  689 
  

  

  AP 
  (and 
  which 
  is 
  the 
  apex 
  of 
  the 
  Wealden 
  excavation) 
  occupied 
  by 
  

   large 
  accumulations 
  of 
  " 
  flint 
  drift 
  " 
  resting 
  upon 
  the 
  Neoconiian. 
  

   Whether 
  this 
  " 
  drift 
  " 
  be 
  gravel, 
  or 
  what 
  it 
  may 
  be, 
  I 
  do 
  not 
  know 
  ; 
  

   but 
  within 
  the 
  same 
  great 
  Wealden 
  excavation, 
  near 
  the 
  centre 
  of 
  

   Sheet 
  8, 
  is 
  an 
  important 
  bed 
  of 
  gravel, 
  because 
  it 
  has 
  been 
  described 
  

   by 
  Mr. 
  Godwin-Austen 
  as 
  having 
  been 
  faulted 
  with 
  the 
  Xeocomian 
  

   formation 
  on 
  which 
  it 
  rests 
  during 
  the 
  earlier 
  part 
  of 
  its 
  accumu- 
  

   lation 
  *. 
  The 
  part 
  where 
  this 
  occurs 
  is 
  represented 
  in 
  the 
  con- 
  

   tinuation 
  of 
  Map 
  2 
  as 
  an 
  island 
  in 
  two 
  parts 
  joined 
  by 
  an 
  isthmus 
  ; 
  

   of 
  which 
  two 
  parts, 
  the 
  northern 
  represents 
  the 
  Chalk 
  Down 
  from 
  

   Gomshall 
  towards 
  Leatherhead, 
  and 
  the 
  southern 
  the 
  lofty 
  Neo- 
  

   comian 
  tract 
  of 
  Leith 
  Hill, 
  Mine 
  Head, 
  and 
  its 
  neighbourhood 
  ; 
  the 
  

   isthmus 
  connecting 
  them 
  being 
  the 
  parting 
  (at 
  about 
  400 
  feet 
  ele- 
  

   vation) 
  between 
  the 
  drainage 
  flowing 
  to 
  the 
  Mole, 
  and 
  that 
  flowing 
  

   to 
  the 
  Wey 
  by 
  the 
  Tillingbourne, 
  and 
  over 
  which 
  parting 
  Sir 
  R. 
  

   Murchison 
  (loc. 
  cit. 
  p. 
  379) 
  describes 
  the 
  same 
  "flint 
  drift" 
  as 
  dis- 
  

   tributed 
  and 
  resting 
  on 
  the 
  Neoconiian 
  sand. 
  

  

  This 
  isthmus 
  was 
  submerged 
  during 
  the 
  time 
  represented 
  by 
  Map 
  4, 
  

   and 
  the 
  two 
  parts 
  formed 
  separate 
  islands; 
  but 
  having 
  at 
  the 
  time 
  of 
  

   Map 
  2 
  emerged, 
  the 
  Tillingbourne 
  valley 
  formed 
  the 
  inlet 
  pene- 
  

   trating 
  this 
  island 
  on 
  the 
  west 
  of 
  the 
  isthmus 
  which 
  is 
  shown 
  in 
  that 
  

   Map 
  ; 
  and 
  in 
  this 
  the 
  faulted 
  gravel 
  accumulated, 
  its 
  elevation 
  being 
  

   241 
  feet 
  above 
  0. 
  D., 
  and 
  more 
  than 
  130 
  above 
  that 
  of 
  the 
  sheet 
  of 
  

   gravel 
  occupying 
  the 
  valley 
  of 
  the 
  Wey 
  and 
  its 
  tributaries, 
  part 
  of 
  

   which 
  is 
  shown 
  under 
  the 
  letter 
  g 
  in 
  figs. 
  II. 
  & 
  III. 
  The 
  faulting 
  of 
  

   this 
  gravel 
  seems 
  to 
  have 
  been 
  connected 
  with 
  the 
  rectilinear 
  dis- 
  

   turbances 
  which, 
  with 
  the 
  great 
  denudation 
  to 
  which 
  these 
  gave 
  

   rise 
  there, 
  have 
  placed 
  the 
  gravel 
  V 
  in 
  the 
  position 
  which 
  it 
  occupies 
  

   in 
  figs. 
  II., 
  III., 
  IV., 
  and 
  V. 
  Mr. 
  Godwin- 
  Austen 
  describes 
  it, 
  as 
  well 
  

   as 
  that 
  on 
  Merrow 
  Down 
  f 
  , 
  as 
  including 
  great 
  blocks 
  of 
  grey- 
  

   wether 
  sandstone. 
  He 
  also 
  says 
  that 
  mammalian 
  remains 
  have 
  

   been 
  met 
  with 
  in 
  the 
  lower 
  portion 
  of 
  this 
  gravel. 
  

  

  Erom 
  this 
  island 
  eastwards 
  the 
  sea 
  is 
  shown 
  as 
  covering 
  the 
  "Weald 
  

   up 
  to 
  elevations 
  which 
  gradually 
  decrease 
  in 
  that 
  direction 
  to 
  200 
  feet 
  

   at 
  the 
  eastern 
  part 
  of 
  the 
  map, 
  but 
  as 
  being 
  in 
  connexion 
  with 
  the 
  sea 
  

   over 
  the 
  Thames 
  system 
  byway 
  of 
  the 
  (Kentish) 
  Stour, 
  theMedway, 
  

   the 
  Darent, 
  the 
  Mole, 
  the 
  Wey, 
  and 
  the 
  low 
  ground 
  near 
  Farnham, 
  the 
  

   elevations 
  of 
  all 
  the 
  partings 
  from 
  the 
  Thames 
  system 
  by 
  any 
  of 
  these 
  

   being 
  below 
  the 
  elevations 
  on 
  which 
  the 
  representation 
  of 
  the 
  sub- 
  

   merged 
  parts 
  of 
  the 
  map 
  is 
  based. 
  Gravels 
  sporadically 
  scattered 
  over 
  

   some 
  of 
  the 
  parts 
  thus 
  represented 
  as 
  covered 
  by 
  sea 
  occur 
  on 
  the 
  

   Weald 
  clay, 
  independently 
  of 
  that 
  which 
  at 
  low 
  levels 
  skirts 
  the 
  

   rivers, 
  and 
  can 
  justly 
  be 
  referred 
  to 
  the 
  action 
  of 
  these 
  when, 
  during 
  

   Stages 
  VI. 
  and 
  VII. 
  they 
  in 
  flood-time 
  were 
  in 
  greater 
  volume 
  than 
  

   now. 
  These 
  patches, 
  which 
  are 
  shown 
  on 
  the 
  Geological 
  Survey 
  map 
  

   of 
  Sheet 
  6, 
  have 
  been 
  referred 
  by 
  Messrs. 
  Topley 
  and 
  Foster^ 
  to 
  the 
  

  

  * 
  Quart. 
  Jo 
  urn. 
  Geol. 
  Soc. 
  vol. 
  vii. 
  p. 
  278. 
  

  

  t 
  Merrow 
  chalk-down 
  at 
  a 
  much 
  higher 
  elevation 
  is 
  also 
  shown 
  by 
  Mr. 
  

   Godwin- 
  Austen 
  as 
  capped 
  by 
  gravel, 
  which 
  I 
  presume 
  is 
  b' 
  of 
  this 
  memoir. 
  

   X 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xxi. 
  p. 
  443. 
  

  

  