﻿696 
  SEAKLES 
  V. 
  WOOD 
  ON 
  THE 
  NEWER 
  

  

  a 
  hollow 
  in 
  the 
  Thanet 
  Sand, 
  which 
  elsewhere 
  in 
  the 
  quarry 
  was 
  

   overlain 
  by 
  the 
  gravel 
  /. 
  The 
  part 
  of 
  No. 
  3 
  which 
  appears 
  there 
  

   is 
  only 
  the 
  uppermost, 
  which, 
  so 
  far 
  as 
  I 
  know, 
  is 
  unfossiliferous. 
  

   The 
  elevation 
  of 
  this 
  seetion 
  is 
  between 
  80 
  and 
  100 
  feet. 
  

  

  The 
  Cyrena 
  -formation 
  appears 
  to 
  occur 
  up 
  the 
  Lea 
  valley 
  at 
  

   Stoke 
  Newington, 
  and 
  to 
  reach 
  there 
  the 
  elevation 
  of 
  about 
  100 
  feet 
  

   above 
  O. 
  D. 
  ; 
  but 
  the 
  Cyrena 
  itself 
  has 
  not 
  been 
  yet 
  found 
  there, 
  

   so 
  far 
  as 
  I 
  know, 
  nor 
  do 
  I 
  know 
  precisely 
  up 
  to 
  what 
  part 
  of 
  this 
  

   elevation 
  shells 
  have 
  occurred*. 
  From 
  the 
  elevation 
  which 
  it 
  there 
  

   attains, 
  however, 
  it 
  must 
  have 
  occupied 
  the 
  Lea 
  valley 
  for 
  a 
  long 
  

   distance 
  to 
  the 
  north 
  of 
  that 
  place 
  ; 
  and, 
  as 
  regards 
  the 
  Thames 
  

   valley, 
  the 
  thick 
  bed 
  of 
  brickearth 
  which 
  occurs 
  at 
  West 
  Drayton, 
  

   Slough, 
  and 
  other 
  places 
  in 
  Sheet 
  7 
  (and 
  which 
  is 
  shown 
  in 
  Map 
  3 
  

   as 
  the 
  C?/r<m«-formation) 
  appears 
  to 
  me 
  to 
  be 
  this 
  bed 
  No. 
  4, 
  

   similarly 
  transgressive, 
  so 
  that 
  it 
  there 
  rests 
  on 
  the 
  gravel 
  /, 
  

   reaching 
  an 
  elevation 
  of 
  120 
  feet 
  ; 
  and 
  it 
  is 
  shown 
  on 
  the 
  Geological- 
  

   Survey 
  map 
  as 
  overlapping 
  the 
  northern 
  edge 
  of 
  /, 
  and 
  resting 
  

   for 
  a 
  considerable 
  distance 
  on 
  the 
  London 
  Clay 
  (see 
  for 
  this 
  also, 
  

   Map 
  3, 
  PL 
  XXVI.). 
  Between 
  there 
  and 
  London, 
  this 
  bed 
  (No. 
  4) 
  

   appears 
  to 
  me 
  to 
  be 
  represented 
  at 
  Acton, 
  in 
  fig. 
  iv. 
  of 
  Col. 
  Lane 
  Fox 
  

   (at 
  page 
  456 
  of 
  the 
  28th 
  vol. 
  of 
  the 
  Journal), 
  by 
  the 
  brickearth 
  with 
  

   seams 
  of 
  sand, 
  which 
  in 
  an 
  adjoining 
  section 
  he 
  describes 
  as 
  

   " 
  passing 
  gradually 
  down 
  into 
  fine 
  yellow 
  sand 
  without 
  stones 
  " 
  

   (the 
  elevation 
  being 
  82 
  feet), 
  that 
  sand, 
  which 
  is 
  gravelly 
  in 
  some 
  

   places, 
  being 
  bed 
  No. 
  3 
  of 
  Grays, 
  though 
  only 
  the 
  remains 
  of 
  a 
  fern, 
  

   and 
  no 
  shells, 
  occurred 
  in 
  it. 
  The 
  transgression 
  is 
  shown 
  at 
  Acton 
  

   by 
  this 
  sand 
  resting 
  on 
  the 
  London 
  Clay 
  at 
  an 
  elevation 
  which, 
  

   relatively 
  to 
  the 
  Thames 
  level, 
  corresponds 
  with 
  that 
  reached 
  by 
  it 
  at 
  

   Grays 
  ; 
  and 
  the 
  occurrence 
  of 
  a 
  tree-trunk 
  on 
  the 
  London-Clay 
  sur- 
  

   face 
  at 
  the 
  base 
  of 
  the 
  sand, 
  shown 
  in 
  Col. 
  Lane 
  Fox's 
  fig. 
  iii., 
  accords 
  

   with 
  that 
  trangression 
  ; 
  but 
  beds 
  1 
  and 
  2, 
  which 
  were 
  confined 
  to 
  

   lower 
  elevations, 
  have 
  been 
  removed 
  to 
  make 
  place 
  for 
  the 
  gravel 
  </, 
  

   described 
  in 
  Stage 
  VII., 
  which 
  about 
  Acton 
  also 
  passes 
  up 
  into 
  brick- 
  

   earth, 
  and 
  is 
  that 
  distinguished 
  by 
  Col. 
  Lane 
  Fox 
  as 
  the 
  gravel 
  of 
  

   the 
  " 
  medium 
  and 
  lower 
  terrace." 
  

  

  This 
  bed 
  No. 
  4 
  occurs 
  in 
  many 
  parts 
  of 
  the 
  Thames 
  valley, 
  but 
  not 
  

   in 
  thickness 
  sufficient 
  for 
  its 
  representation 
  inMap3,the 
  scale 
  of 
  which 
  

   only 
  allows 
  of 
  the 
  representation 
  of 
  the 
  Cyrena-form&tion 
  on 
  it 
  where 
  

   some 
  part 
  of 
  this 
  is 
  worked 
  for 
  bricks 
  ; 
  and, 
  as 
  I 
  have 
  already 
  said, 
  

   probably 
  both 
  in 
  the 
  Geological- 
  Survey 
  map 
  and 
  in 
  mine, 
  some 
  and 
  

   perhaps 
  much 
  of 
  what 
  is 
  shown 
  as 
  gravel 
  / 
  may 
  be 
  the 
  sand 
  No. 
  3. 
  

   Judging 
  from 
  the 
  greater 
  thickness 
  of 
  No. 
  4 
  at 
  Slough 
  railway-cutting, 
  

   it 
  seems 
  elsewhere 
  to 
  have 
  been 
  reduced 
  by 
  denudation 
  during 
  

   emergence 
  ; 
  and 
  in 
  the 
  smaller 
  thickness 
  thus 
  resulting 
  it 
  rests 
  on 
  

   gravel 
  /, 
  in 
  the 
  railway 
  ballast-pit 
  at 
  Chadwell 
  Heath 
  in 
  Sheet 
  1, 
  at 
  

   between 
  60 
  and 
  70 
  feet 
  elevation, 
  and 
  seems 
  to 
  form 
  a 
  thin 
  surface- 
  

   bed 
  over 
  much 
  of 
  the 
  area 
  between 
  there 
  and 
  the 
  line 
  of 
  fig. 
  XXIX. 
  

   It 
  is 
  worked 
  for 
  bricks 
  over 
  f 
  between 
  Southend 
  and 
  Prittlewell, 
  

   and 
  much 
  of 
  the 
  country 
  north 
  of 
  Southend, 
  at 
  elevations 
  which, 
  

   allowing 
  for 
  the 
  fall 
  of 
  the 
  valley, 
  correspond 
  with 
  those 
  higher 
  up 
  

   * 
  See, 
  however, 
  note 
  at 
  page 
  741. 
  

  

  