﻿66$ 
  SEARLES 
  V. 
  WOOD 
  ON 
  THE 
  NEWER 
  

  

  though 
  passing 
  over 
  these 
  islands, 
  issued 
  mainly 
  to 
  the 
  sea 
  by 
  glaciers 
  

   through 
  the 
  channels 
  between 
  them, 
  which 
  have 
  since 
  become 
  our 
  

   river-valleys, 
  though, 
  from 
  the 
  greatly 
  different 
  inclination 
  of 
  the 
  

   country, 
  this 
  in 
  the 
  case 
  of 
  the 
  Trent 
  and 
  all 
  the 
  rivers 
  flowing 
  to 
  

   the 
  Wash, 
  took 
  place 
  in 
  the 
  reverse 
  direction 
  to 
  the 
  present 
  flow 
  of 
  

   those 
  rivers 
  ; 
  and 
  how, 
  in 
  consequence, 
  the 
  moraine 
  of 
  Chalky 
  Clay 
  

   laid 
  down 
  in 
  these 
  channels 
  had, 
  upon 
  the 
  recession 
  from 
  it 
  of 
  the 
  

   ice, 
  been 
  overflowed 
  by 
  the 
  sea 
  up 
  to 
  the 
  level 
  which 
  then, 
  accord- 
  

   ing 
  to 
  the 
  different 
  inclination 
  of 
  the 
  country, 
  corresponded 
  with 
  the 
  

   sea-surface 
  ; 
  so 
  that 
  gravel, 
  which 
  was 
  merely 
  a 
  continuation 
  of 
  that 
  

   upon 
  which 
  this 
  moraine 
  had 
  as 
  a 
  mud-bank 
  been 
  first 
  pushed, 
  

   became 
  spread 
  over 
  the 
  moraine 
  within 
  this 
  limit 
  of 
  level. 
  In 
  the 
  

   north-west 
  of 
  England, 
  where, 
  from 
  the 
  depression 
  being 
  greatest, 
  

   the 
  water 
  was 
  deepest, 
  the 
  moraine 
  was, 
  I 
  endeavoured 
  to 
  show, 
  

   extruded 
  not 
  in 
  this 
  way, 
  but 
  beneath 
  the 
  sea, 
  thereby 
  giving 
  rise 
  to 
  

   the 
  Lower 
  Boulder 
  Clay 
  of 
  that 
  region 
  (D') 
  — 
  a 
  process 
  in 
  which 
  I 
  re- 
  

   garded 
  the 
  Purple 
  Clay 
  of 
  Yorkshire 
  (D) 
  also 
  as 
  having 
  begun, 
  

   though 
  ending 
  by 
  terrestrial 
  accumulation 
  after 
  Yorkshire 
  had 
  

   emerged, 
  the 
  material 
  of 
  that 
  clay 
  having 
  been 
  moraine 
  furnished 
  

   by 
  ice 
  flowing 
  from 
  the 
  Tees 
  valley 
  southwards 
  along 
  the 
  east 
  side 
  

   of 
  Yorkshire, 
  which 
  was 
  recruited 
  by 
  ice 
  from 
  the 
  Westmoreland 
  

   mountains 
  crossing 
  the 
  Pennine, 
  and 
  bringing 
  the 
  Shap 
  blocks. 
  

  

  In 
  tracing 
  the 
  first 
  part 
  of 
  this 
  great 
  movement 
  of 
  subsidence 
  and 
  

   elevation, 
  I 
  explained 
  how, 
  in 
  proportion 
  to 
  its 
  contiguity 
  to 
  the 
  ice, 
  

   the 
  sea-bed 
  became 
  the 
  receptacle 
  of 
  chalk-debris 
  and 
  chalky 
  silt, 
  

   produced 
  by 
  the 
  action 
  of 
  the 
  land-ice 
  upon 
  the 
  Lincolnshire 
  and 
  

   Yorkshire 
  Wolds; 
  and 
  that 
  this, 
  before 
  the 
  extension 
  of 
  the 
  depression 
  

   had 
  carried 
  the 
  sea 
  over 
  all 
  England, 
  and 
  while 
  some 
  of 
  the 
  Mollusca 
  

   of 
  the 
  Crag 
  which 
  appear 
  to 
  have 
  since 
  become 
  extinct 
  yet 
  survived, 
  

   gave 
  rise 
  to 
  the 
  Cromer 
  Till 
  (&#), 
  a 
  local 
  modification 
  of 
  the 
  sands 
  bl; 
  

   while 
  the 
  actual 
  submoraine 
  of 
  the 
  ice 
  of 
  this 
  date, 
  and 
  from 
  which 
  

   the 
  silt, 
  mud, 
  and 
  chalk-debris 
  of 
  the 
  Cromer 
  Till 
  proceeded, 
  is 
  

   represented 
  by 
  the 
  Basement 
  Clay 
  of 
  Holderness 
  (B), 
  which 
  is 
  

   chiefly 
  composed 
  of 
  a 
  reconstruction 
  of 
  the 
  Jurassic 
  clays 
  and 
  hard 
  

   chalk 
  of 
  Yorkshire, 
  and 
  in 
  the 
  upper 
  part 
  of 
  which, 
  as 
  the 
  ice 
  was 
  

   receding 
  from 
  it, 
  thin 
  beds 
  of 
  sand 
  containing 
  the 
  remains 
  of 
  these 
  

   extinct 
  Mollusca 
  were 
  formed 
  by 
  the 
  intruding 
  sea. 
  I 
  then 
  described 
  

   how, 
  as 
  this 
  recession 
  went 
  on, 
  the 
  Cromer 
  Till 
  changed 
  to 
  a 
  brick- 
  

   earth 
  mud 
  ibS), 
  which, 
  in 
  proportion 
  to 
  its 
  , 
  propinquity 
  to 
  the 
  Wold, 
  

   was 
  interstratified 
  with, 
  or 
  even 
  made 
  up 
  of 
  chalk-silt 
  and 
  fine 
  chalk- 
  

   debris, 
  and 
  which, 
  towards 
  its 
  close 
  (and 
  before 
  the 
  change 
  of 
  move- 
  

   ment 
  to 
  one 
  of 
  elevation 
  gave 
  rise 
  to 
  an 
  advance 
  of 
  the 
  ice, 
  and 
  to 
  

   the 
  overspread 
  of 
  this 
  mud 
  by 
  the 
  gravel 
  c) 
  was 
  contorted 
  by 
  the 
  

   grounding 
  in 
  it 
  of 
  ice 
  detached 
  from 
  that 
  which 
  rested 
  on 
  the 
  Wold, 
  

   and. 
  bringing 
  thence 
  masses 
  of 
  the 
  moraine 
  of 
  reconstructed 
  chalk 
  

   extruded 
  there, 
  which 
  were 
  thus 
  buried 
  and 
  left 
  in 
  the 
  mud 
  and 
  

   subjacent 
  Till 
  ; 
  so 
  that 
  in 
  this 
  way 
  the 
  sand 
  and 
  gravel 
  6' 
  repre- 
  

   sented 
  this 
  brickearth 
  in 
  the 
  parts 
  more 
  distant 
  from 
  the 
  ice 
  — 
  

   b 
  1 
  and 
  6 
  2 
  having 
  been 
  deposited 
  before 
  the 
  progress 
  of 
  the 
  de- 
  

   pression 
  had 
  carried 
  the 
  sea 
  from 
  East 
  Anglia, 
  generally 
  over 
  Eng- 
  

  

  