﻿690 
  

  

  SEARLES 
  V. 
  WOOD 
  ON 
  THE 
  NEWER 
  

  

  deposit 
  of 
  the 
  river 
  Medway 
  and 
  its 
  tributaries, 
  when 
  the 
  Medway 
  

   system 
  ran 
  at 
  a 
  proportionately 
  higher 
  level 
  ; 
  and 
  in 
  order 
  to 
  reconcile 
  

   this 
  with 
  even 
  the 
  largest 
  conceivable 
  volume 
  that 
  could 
  be 
  assigned 
  

   to 
  the 
  rivers, 
  they 
  are 
  compelled 
  to 
  assume 
  an 
  enormous 
  nuviatile 
  ex- 
  

   cavation 
  as 
  having 
  succeeded 
  (and 
  in 
  a 
  less 
  degree 
  also 
  accompanied) 
  

   the 
  deposition 
  of 
  this 
  gravel 
  ; 
  for 
  the 
  patches 
  reach 
  to 
  upwards 
  of 
  

   200 
  feet 
  above 
  the 
  rivers, 
  and 
  300 
  above 
  O. 
  D. 
  The 
  Lower-Tertiary 
  

   pebbles 
  and 
  subangular 
  chalk-flints 
  which 
  some 
  of 
  these 
  gravel- 
  

   patches 
  contain 
  more 
  or 
  less 
  abundantly, 
  notwithstanding 
  that 
  they 
  

   are 
  separated 
  from 
  the 
  Chalk 
  by 
  the 
  Neocomian 
  escarpment, 
  and 
  from 
  

   the 
  Lower 
  Tertiaries 
  by 
  both 
  that 
  and 
  the 
  Chalk 
  escarpment, 
  and 
  

   notwithstanding 
  that 
  in 
  some 
  cases 
  the 
  rivers 
  of 
  their 
  neighbourhood 
  

   do 
  not 
  reach 
  the 
  Chalk, 
  much 
  less 
  the 
  Lower-Tertiary 
  area, 
  are 
  

   regarded 
  by 
  these 
  gentlemen 
  as 
  having 
  been 
  brought 
  by 
  streams 
  

   which, 
  prior 
  to 
  this 
  enormous 
  river-excavation, 
  were 
  tributary 
  to 
  

   those 
  rivers 
  when 
  they 
  ran 
  at 
  proportionately 
  high 
  levels, 
  and 
  

   being 
  thus 
  tributary, 
  flowed 
  over 
  great 
  areas 
  of 
  Neocomian 
  and 
  

   Gault, 
  and 
  even 
  Chalk, 
  which 
  have 
  since 
  been 
  removed 
  along 
  with 
  

   parts 
  of 
  such 
  tributary 
  streams 
  themselves. 
  

  

  This 
  view 
  I 
  have 
  for 
  many 
  years 
  discredited 
  ; 
  and 
  the 
  first 
  thing 
  

   which 
  presents 
  itself 
  in 
  opposition 
  to 
  it 
  is, 
  why, 
  since 
  the 
  height 
  

   attained 
  in 
  so 
  many 
  places 
  by 
  gravel 
  6' 
  shows 
  that 
  this 
  part 
  of 
  

   England 
  was 
  submerged 
  far 
  above 
  these 
  gravel-patches, 
  so 
  vast 
  

   a 
  nuviatile 
  denudation 
  should 
  have 
  occurred 
  in 
  this 
  region, 
  when 
  

   the 
  corresponding 
  area 
  north 
  of 
  the 
  Thames 
  shows 
  nothing 
  of 
  the 
  

   kind 
  ? 
  Why, 
  for 
  instance, 
  should 
  the 
  river- 
  valleys 
  of 
  East 
  Anglia 
  

   have 
  undergone 
  no 
  appreciable 
  denudation 
  since 
  the 
  ice 
  of 
  the 
  

   Chalky 
  Clay 
  deserted 
  them, 
  while 
  those 
  of 
  the 
  Weald 
  during 
  the 
  

   same 
  time 
  have 
  undergone 
  so 
  vast 
  an 
  excavation 
  ? 
  The 
  section 
  of 
  

   Prof. 
  Hughes's 
  which 
  I 
  have 
  reproduced 
  (p. 
  678) 
  shows 
  no 
  denudation 
  

   of 
  the 
  Hertfordshire 
  valleys 
  since 
  the 
  Chalky 
  Clay 
  plunged 
  into 
  

   1hem 
  (as 
  it 
  did 
  in 
  all 
  the 
  valleys 
  of 
  the 
  area 
  occupied 
  by 
  it) 
  ; 
  and 
  

   figs, 
  VI., 
  VII., 
  and 
  XL. 
  show 
  the 
  same 
  for 
  the 
  valleys 
  of 
  Essex, 
  as 
  

   do 
  figs. 
  I., 
  VIII., 
  and 
  IX. 
  for 
  the 
  valleys 
  of 
  Suffolk 
  and 
  Norfolk. 
  

  

  The 
  next 
  thing 
  in 
  reference 
  to 
  this 
  view 
  that 
  demands 
  inquiry 
  

   is, 
  What 
  is 
  there 
  in 
  these 
  gravels 
  to 
  indicate 
  a 
  nuviatile 
  origin, 
  and 
  to 
  

   rebut 
  the 
  contrary 
  inference 
  afforded 
  by 
  the 
  extraneous 
  debris 
  present 
  

   in 
  them, 
  to 
  explain 
  which 
  such 
  large 
  postulates 
  have 
  been 
  demanded 
  ? 
  

  

  No 
  nuviatile 
  shells, 
  so 
  far 
  as 
  I 
  know, 
  have 
  been 
  found 
  in 
  them, 
  

   though 
  such 
  have 
  been 
  found 
  in 
  the 
  gravels 
  skirting 
  the 
  rivers 
  at 
  

   low 
  elevations, 
  which 
  are 
  admitted 
  to 
  be 
  of 
  nuviatile 
  origin. 
  All 
  

   that 
  has 
  been 
  found 
  in 
  the 
  former 
  in 
  the 
  shape 
  of 
  organic 
  remains 
  are 
  

   those 
  of 
  mammalia 
  (and 
  these, 
  so 
  far 
  as 
  I 
  know, 
  only 
  in 
  one 
  case, 
  viz. 
  

   at 
  Marden, 
  and 
  there 
  in 
  abouldered 
  condition) 
  and 
  some 
  paleolithic 
  

   implements 
  *. 
  The 
  latter 
  have 
  occurred 
  in 
  the 
  inlet 
  gravel 
  of 
  the 
  

  

  * 
  The 
  implements 
  have 
  occurred 
  in 
  the 
  gravels 
  of 
  the 
  Plaxtole 
  rivulet 
  valley 
  

   in 
  the 
  exact 
  centre 
  of 
  Sheet 
  6. 
  Some 
  of 
  these 
  gravels 
  according 
  to 
  Mr. 
  Smith 
  

   (in 
  vol. 
  xxiv. 
  of 
  ' 
  Nature,' 
  p. 
  30) 
  are 
  400 
  feet 
  above 
  O. 
  D., 
  and 
  about 
  100 
  above 
  

   the 
  rivulet. 
  The 
  gravels 
  thus 
  containing 
  implements 
  extend 
  along 
  the 
  rivulet 
  

   valley 
  from 
  400 
  feet 
  at 
  Ingtham 
  to 
  200 
  at 
  Dunks 
  Green, 
  a 
  distance 
  of 
  only 
  four 
  

   miles. 
  Such 
  of 
  this 
  gravel 
  as 
  is 
  on 
  the 
  Weald 
  clay 
  contains 
  subangular 
  flints 
  and 
  

   Lower-Tertiary 
  pebbles, 
  though 
  the 
  source 
  of 
  the 
  rivulet 
  is 
  in 
  the 
  Neocomian. 
  

  

  