﻿MA.EINE 
  DKIFTS 
  Df 
  NOETH 
  WALES. 
  195 
  

  

  1. 
  High-level 
  marine 
  drifts, 
  in 
  addition 
  to 
  directly 
  local 
  stones 
  

   and 
  stones 
  from 
  neighbouring 
  areas, 
  consist 
  to 
  a 
  greater 
  or 
  less 
  

   extent 
  of 
  far-travelled 
  erratic 
  stones, 
  while 
  in 
  none 
  of 
  them 
  are 
  the 
  

   stones 
  entirely 
  local. 
  

  

  2. 
  The 
  stones 
  are 
  generally 
  much 
  rounded, 
  and 
  that 
  frequently 
  

   over 
  large 
  areas. 
  

  

  3. 
  All 
  the 
  great 
  drift-areas 
  contain 
  a 
  considerable, 
  and 
  some 
  of 
  

   them 
  a 
  large 
  percentage 
  of 
  granite, 
  especially 
  Eskdale 
  granite, 
  

   which 
  is 
  at 
  least 
  partly 
  owing 
  to 
  the 
  extent 
  to 
  which 
  the 
  Eskdale 
  

   area 
  is 
  covered 
  with 
  granite 
  fragments 
  and 
  pebbles 
  in 
  positions 
  

   favourable 
  to 
  removal 
  by 
  floating 
  ice. 
  

  

  4. 
  All 
  the 
  great 
  drift 
  areas 
  (so 
  far 
  as 
  yet 
  known) 
  are 
  situated 
  on 
  

   or 
  towards 
  the 
  outer 
  slopes 
  of 
  mountain 
  districts. 
  

  

  5. 
  In 
  the 
  interior 
  of 
  mountain 
  districts 
  high-level 
  drifts 
  are 
  either 
  

   absent 
  or 
  limited 
  to 
  patches. 
  

  

  6. 
  The 
  drift- 
  areas 
  are 
  more 
  or 
  less 
  bounded 
  above 
  and 
  below, 
  as 
  

   well 
  as 
  longitudinally, 
  by 
  areas 
  in 
  which 
  the 
  stones 
  are 
  angular 
  or 
  

   subangular. 
  

  

  7. 
  None 
  of 
  them 
  are 
  situated 
  further 
  south 
  than 
  latitudes 
  in 
  which 
  

   both 
  land 
  ice 
  and 
  floating 
  ice 
  may 
  at 
  one 
  time 
  have 
  existed. 
  

  

  8. 
  In 
  all 
  the 
  areas 
  there 
  is 
  a 
  tendency 
  to 
  a 
  knoll- 
  shaped 
  con- 
  

   figuration, 
  and 
  in 
  a 
  greater 
  or 
  less 
  number 
  of 
  instances 
  a 
  tendency 
  

   in 
  the 
  knolls 
  to 
  occupy 
  perched 
  positions. 
  

  

  9. 
  The 
  gravel 
  and 
  sand 
  generally 
  contains 
  very 
  few 
  large 
  

   boulders 
  : 
  but 
  the 
  latter 
  are 
  common 
  in 
  and 
  on 
  the 
  surface 
  of 
  the 
  

   clay, 
  which 
  generally 
  overlies, 
  but 
  in 
  many 
  instances 
  graduates 
  (on 
  

   the 
  same 
  horizon) 
  into 
  gravel 
  and 
  sand. 
  

  

  10. 
  The 
  shells 
  found 
  in 
  the 
  drift 
  are 
  almost 
  universally 
  frag- 
  

   mentary, 
  and 
  that 
  often, 
  if 
  not 
  generally, 
  in 
  proportion 
  to 
  the 
  

   roundness 
  of 
  the 
  associated 
  stones. 
  They 
  are 
  likewise 
  often 
  con- 
  

   fined 
  to 
  particular 
  spots, 
  as 
  if 
  elsewhere 
  they 
  had 
  never 
  been 
  present, 
  

   or 
  had 
  been 
  destroyed 
  by 
  the 
  stranding 
  of 
  floating 
  ice, 
  as 
  is 
  the 
  case 
  

   on 
  many 
  Arctic 
  sea- 
  shores 
  at 
  the 
  present 
  day. 
  

  

  11. 
  The 
  idea 
  of 
  shell-fragments 
  having 
  been 
  pushed 
  up 
  hill 
  along 
  

   with 
  portions 
  of 
  existing 
  sea-beds 
  is 
  opposed 
  by 
  so 
  many 
  facts 
  as 
  to 
  

   render 
  it 
  altogether 
  untenable. 
  

  

  12. 
  The 
  extent 
  to 
  which 
  the 
  form 
  of 
  the 
  ground 
  has 
  been 
  pre- 
  

   served 
  since 
  the 
  close 
  of 
  the 
  great 
  submergence 
  can 
  only 
  be 
  explained 
  

   by 
  supposing 
  that 
  either 
  the 
  time 
  which 
  has 
  elapsed 
  since 
  that 
  

   event, 
  or 
  the 
  rate 
  of 
  subaerial 
  denudation 
  during 
  that 
  time, 
  has 
  

   been 
  overestimated 
  ; 
  in 
  other 
  words, 
  the 
  denudation 
  must 
  have 
  been 
  

   slow 
  in 
  proportion 
  to 
  the 
  length 
  of 
  time 
  in 
  order 
  to 
  account 
  for 
  the 
  

   little- 
  altered 
  surface-configuration 
  of 
  the 
  drift-areas 
  described 
  in 
  

   this 
  and 
  in 
  my 
  former 
  paper*. 
  

  

  * 
  In 
  these 
  areas 
  there 
  is 
  an 
  absence 
  of 
  the 
  kind 
  of 
  gravel 
  which 
  a 
  glacier 
  

   would 
  have 
  brought 
  along 
  with 
  shells 
  from 
  the 
  preglacial 
  bed 
  of 
  the 
  Irish 
  

  

  