﻿288 
  PROF. 
  J. 
  PRESTWICH 
  ON 
  THE 
  OCCURRENCE 
  OF 
  

  

  from 
  400 
  to 
  500 
  ft., 
  on 
  the 
  east 
  slopes 
  of 
  Oldbury. 
  In 
  the 
  Shode-basin 
  

   Mr. 
  Harrison 
  found, 
  near 
  Crouch 
  Point, 
  at 
  the 
  height 
  of 
  400 
  ft., 
  

   a 
  whitish 
  flint 
  scraper 
  imbedded 
  under 
  3 
  or 
  4 
  ft. 
  of 
  brick-earth. 
  

   Similar 
  white 
  and 
  sharp 
  specimens 
  are 
  found 
  on 
  the 
  surface 
  at 
  

   Bewley, 
  Bitchet, 
  and 
  other 
  places, 
  though 
  no 
  traces 
  of 
  brick-earth 
  

   are 
  there 
  visible. 
  

  

  I 
  consider 
  it 
  therefore 
  more 
  than 
  probable 
  that 
  all 
  these 
  specimens 
  

   have 
  originally 
  been 
  imbedded 
  in 
  a 
  brick-earth 
  or 
  loess, 
  which 
  has 
  

   been 
  denuded 
  away, 
  and 
  that 
  this 
  district 
  had 
  originally 
  a 
  covering 
  

   of 
  loess, 
  which 
  seems 
  to 
  have 
  reached 
  to 
  a 
  height 
  of 
  550 
  ft. 
  and 
  

   possibly 
  more. 
  Nor 
  are 
  we 
  without 
  corroborating 
  evidence. 
  On 
  the 
  

   hill 
  between 
  Crowhurst 
  and 
  Highfield 
  there 
  is 
  a 
  bare 
  plateau 
  of 
  

   Kentish 
  Eag, 
  344 
  ft. 
  above 
  O.D. 
  and 
  144 
  ft. 
  above 
  the 
  Shode. 
  

   In 
  passing 
  by, 
  Mr. 
  Harrison 
  informed 
  me 
  that 
  in 
  trenching 
  or 
  

   ploughing 
  the 
  fields 
  a 
  number 
  of 
  fissures 
  or 
  pipes 
  of 
  a 
  red 
  clay 
  had 
  

   been 
  met 
  with, 
  while 
  the 
  Eagstone 
  between 
  them 
  presented 
  a 
  bare 
  

   surface. 
  Now 
  this 
  could 
  only 
  have 
  occurred 
  by 
  the 
  surface 
  having 
  

   been 
  originally 
  covered 
  by 
  a 
  uniform 
  bed 
  of 
  clay 
  or 
  loess, 
  which, 
  

   as 
  the 
  Eagstone 
  was 
  rent 
  or 
  worn 
  away 
  beneath 
  it 
  by 
  the 
  passage 
  

   downwards 
  of 
  the 
  surface-waters, 
  subsided 
  into 
  the 
  cavities 
  so 
  

   formed, 
  and 
  was 
  there 
  protected 
  from 
  the 
  denudation 
  which 
  subse- 
  

   quently 
  removed 
  the 
  exposed 
  portions 
  of 
  the 
  clay. 
  It 
  is 
  a 
  case 
  

   analogous 
  to 
  the 
  preservation 
  of 
  Lower 
  Tertiary 
  sands 
  and 
  clays 
  in 
  

   pipes 
  on 
  a 
  bare 
  Chalk 
  surface, 
  or 
  to 
  that 
  of 
  the 
  Pliocene 
  (Crag) 
  

   beds 
  on 
  the 
  Chalk-escarpment 
  above 
  Lenham*. 
  For 
  the 
  denu- 
  

   dation 
  of 
  such 
  soft 
  beds 
  of 
  brick-earth 
  or 
  loess, 
  the 
  rainfall, 
  espe- 
  

   cially 
  if 
  heavy 
  and 
  long-continued, 
  as 
  we 
  have 
  reason 
  to 
  suppose 
  

   it 
  was 
  during 
  the 
  Pleistocene 
  period, 
  might 
  have 
  sufficed 
  for 
  its 
  re- 
  

   moval 
  to 
  a 
  great 
  extent, 
  except 
  in 
  the 
  more 
  sheltered 
  places, 
  leaving 
  

   the 
  heavier 
  flints, 
  which 
  it 
  may 
  have 
  contained 
  in 
  situ, 
  on 
  the 
  surface 
  

   of 
  the 
  denuded 
  ground 
  beneath. 
  No 
  powerful 
  denudation 
  by 
  large 
  

   bodies 
  of 
  water, 
  or 
  otherwise, 
  is 
  needed 
  to 
  effect 
  this 
  object. 
  It 
  

   is 
  one 
  common 
  to 
  all 
  time. 
  

  

  A 
  certain 
  number 
  of 
  the 
  third 
  class 
  of 
  implements 
  are 
  found 
  

   associated 
  with 
  the 
  river-valley 
  and 
  hill 
  drifts, 
  and 
  while 
  some 
  of 
  

   them 
  may 
  be 
  local 
  and 
  contemporaneous, 
  others 
  appear 
  to 
  be 
  derived 
  

   from 
  an 
  older 
  drift. 
  These 
  are 
  generally 
  much 
  rolled 
  and 
  worn, 
  

   and 
  present 
  a 
  marked 
  contrast 
  in 
  make, 
  colour, 
  and 
  wear 
  to 
  the 
  

   other 
  specimens 
  with 
  which 
  they 
  are 
  associated 
  ; 
  not 
  but 
  that 
  we 
  

   may 
  find 
  in 
  any 
  valley 
  drift 
  specimens 
  showing 
  equally 
  great 
  

   differences 
  of 
  wear 
  caused 
  by 
  the 
  shingle 
  when 
  drifting 
  in 
  the 
  

   old 
  rivers 
  ; 
  but 
  those 
  to 
  which 
  I 
  allude 
  present 
  other 
  points 
  of 
  dif- 
  

   ference, 
  which 
  induce 
  me 
  to 
  think 
  that 
  they 
  may 
  be 
  derived 
  from 
  

   older 
  beds. 
  The 
  type 
  of 
  this 
  class 
  is 
  that 
  afforded 
  by 
  the 
  specimens 
  

   found 
  at 
  Ash, 
  the 
  bulk 
  of 
  which 
  are, 
  with 
  a 
  few 
  exceptions, 
  

   singularly 
  rude, 
  of 
  a 
  deep 
  ochreous 
  or 
  brown 
  colour, 
  and 
  generally 
  

   rolled 
  and 
  worn. 
  They 
  are 
  like 
  in 
  colour, 
  and 
  some 
  almost 
  in 
  wear, 
  

   to 
  the 
  worn, 
  brown- 
  stained, 
  flint 
  debris 
  by 
  which 
  they 
  are 
  accom- 
  

   panied. 
  It 
  is 
  important 
  to 
  note 
  also, 
  as 
  affording 
  a 
  clue 
  to 
  the 
  

   * 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xiv. 
  p. 
  322. 
  

  

  