﻿636 
  MR. 
  H. 
  G. 
  LYONS 
  ON" 
  THE 
  BAGSHOT 
  BEDS 
  

  

  without 
  the 
  limits 
  of 
  this 
  map 
  will, 
  I 
  think, 
  run 
  to 
  Hazley 
  Heath 
  *, 
  

   where 
  the 
  pebble-bed 
  is 
  about 
  290', 
  and 
  to 
  Shapely 
  Heath, 
  where 
  

   it 
  is 
  about 
  300'. 
  

  

  The 
  anticlinal 
  shown 
  through 
  Hagthorn 
  Hill, 
  Swinley 
  Park, 
  

   and 
  Caesar's 
  Camp, 
  having 
  a 
  direction 
  roughl}- 
  S."W. 
  and 
  N.E., 
  seems 
  

   to 
  me 
  to 
  explain 
  the 
  rises 
  of 
  the 
  beds 
  mentioned 
  by 
  Dr. 
  Irving 
  

   (Q. 
  J". 
  G. 
  S. 
  vol. 
  xliv. 
  p. 
  166), 
  — 
  viz. 
  (1) 
  the 
  rise 
  of 
  the 
  base 
  of 
  the 
  

   Middle 
  group 
  as 
  it 
  passes 
  eastwards 
  along 
  Nine-mile 
  Ride 
  ; 
  (2) 
  

   the 
  slight 
  rise 
  of 
  the 
  beds 
  of 
  the 
  same 
  horizon 
  from 
  Wokingham 
  

   to 
  Bracknell 
  ; 
  (3) 
  the 
  dip 
  to 
  the 
  westward 
  of 
  the 
  clay 
  and 
  sand 
  beds 
  

   at 
  Bracknell, 
  — 
  and 
  to 
  do 
  so 
  better 
  than 
  the 
  N.W.-S.E. 
  anticlinal, 
  

   which 
  he 
  there 
  postulates, 
  and 
  of 
  which 
  there 
  is 
  no 
  evidence 
  in 
  

   Windlesham. 
  

  

  Next 
  we 
  have 
  a 
  well-marked 
  synclinal 
  starting 
  by 
  Minley 
  and 
  

   Hawley 
  and 
  running 
  by 
  the 
  Eoyal 
  Albert 
  Asylum 
  and 
  Gordon 
  Boys' 
  

   Home, 
  upon 
  Ongar 
  and 
  Row 
  Hills 
  and 
  Woburn 
  Hill. 
  

  

  A 
  curious 
  point 
  is 
  the 
  group 
  of 
  low 
  levels 
  round 
  Pirbright 
  Green. 
  

   I 
  believe 
  they 
  are 
  for 
  the 
  most 
  part 
  correct; 
  for 
  in 
  one 
  case 
  close 
  to 
  

   the 
  railway-bridge 
  north 
  of 
  Dawnay's 
  Hill 
  there 
  is 
  an 
  Upper-Bagshol 
  

   sand-pit 
  at 
  156', 
  where 
  Mr. 
  Hemes 
  t 
  obtained 
  fossils. 
  I 
  have 
  had 
  

   135' 
  O.D. 
  given 
  to 
  me 
  as 
  the 
  level 
  of 
  the 
  top 
  of 
  the 
  Middle 
  Bagshot 
  

   at 
  the 
  Manor 
  House, 
  Pirbright 
  ; 
  and 
  if 
  this 
  is 
  correct 
  the 
  case 
  of 
  

   these 
  grouped 
  low 
  levels 
  is 
  even 
  more 
  remarkable. 
  

  

  Then 
  we 
  have 
  the 
  anticlinal 
  running 
  on 
  to 
  St. 
  George's 
  Hill, 
  

   Weybridge, 
  and 
  the 
  northern 
  slope 
  of 
  this 
  will, 
  it 
  seems 
  lo 
  me, 
  give 
  

   the 
  fall 
  of 
  the 
  surface 
  of 
  London 
  Clay 
  in 
  a 
  direction 
  E.N.E. 
  to 
  W.S.W. 
  

   as 
  noted 
  by 
  Mr. 
  Hudleston 
  t 
  ; 
  for 
  from 
  this 
  paper 
  of 
  Mr. 
  Hudleston's 
  

   we 
  have 
  the 
  base 
  of 
  the 
  Bagshots 
  658 
  yards 
  west 
  of 
  Walton 
  Station 
  

   at 
  +85' 
  O.D., 
  and 
  2 
  J 
  miles 
  off, 
  at 
  the 
  railway-bridge 
  over 
  the 
  

   River 
  Wey, 
  it 
  is 
  at 
  +30' 
  O.D. 
  ; 
  so 
  if 
  we 
  add 
  180' 
  to 
  these 
  we 
  shall 
  

   get 
  265' 
  O.D. 
  and 
  210' 
  O.D. 
  as 
  the 
  top 
  of 
  the 
  Bagshot 
  series 
  

   originally, 
  which 
  helps 
  to 
  give 
  us 
  the 
  direction 
  of 
  this 
  anticlinal 
  ridge. 
  

  

  Similarly 
  the 
  Swinley 
  anticlinal 
  roll 
  will 
  give 
  the 
  slight 
  tilt 
  to 
  

   the 
  westward 
  which 
  Dr. 
  Irving 
  notices 
  §, 
  and 
  the 
  southern 
  side 
  

   of 
  it 
  perhaps 
  that 
  dip 
  to 
  the 
  S.E. 
  he 
  described 
  under 
  Einchampstead 
  

   Church. 
  No 
  doubt 
  more 
  stratigraphical 
  details 
  would 
  alter 
  to 
  some 
  

   extent, 
  and 
  perhaps 
  considerably, 
  my 
  delineation 
  ; 
  but 
  I 
  believe 
  the 
  

   dominant 
  features 
  of 
  it 
  will 
  be 
  found 
  to 
  remain 
  the 
  same. 
  

  

  To 
  the 
  north-east 
  of 
  Chobham 
  Common 
  the 
  Bagshot 
  sands 
  begin 
  to 
  

   disappear 
  on 
  the 
  line 
  of 
  Chertsey 
  and 
  Egham 
  ; 
  but 
  it 
  may 
  be 
  worth 
  

   while 
  to 
  see 
  what 
  altitudes 
  will 
  be 
  obtained 
  by 
  restoring 
  a 
  thickness 
  

   of 
  about 
  180 
  feet 
  for 
  the 
  Middle 
  and 
  Lower 
  Bagshots 
  where 
  they 
  

   have 
  been 
  removed. 
  

  

  At 
  Chertsey 
  Brewery 
  || 
  the 
  London 
  Clay 
  is 
  386 
  feet 
  thick, 
  and 
  has 
  

   its 
  upper 
  surface 
  at 
  a 
  level 
  of 
  0' 
  O.D. 
  

  

  Next, 
  taking 
  the 
  Holloway 
  Sanatorium 
  near 
  Thorpe, 
  about 
  1| 
  

  

  * 
  Messrs 
  Gardner, 
  Keeping, 
  and 
  Monckton, 
  Q. 
  J. 
  G. 
  S. 
  vol. 
  xliv. 
  p. 
  613. 
  

   t 
  lorn. 
  cit. 
  p. 
  612. 
  \ 
  Ibid. 
  vol. 
  xliii. 
  p. 
  451. 
  § 
  Ibid. 
  vol. 
  xliv. 
  p. 
  169. 
  

  

  || 
  Mr. 
  W. 
  Wliitaker," 
  Surrey 
  Wells 
  and 
  their 
  teaching," 
  Croydon 
  Micro, 
  

   and 
  JS 
  T 
  at. 
  Hist. 
  Club, 
  1886. 
  

  

  