﻿820 
  . 
  T. 
  E. 
  JAMTESON 
  ON 
  THE 
  LAST 
  STAGE 
  OF 
  

  

  Mr. 
  Trimmer, 
  who 
  devoted 
  much, 
  attention 
  to 
  the 
  superficial 
  accu- 
  

   mulations 
  of 
  England, 
  and 
  sought 
  to 
  explain 
  them 
  chiefly 
  by 
  the 
  

   action 
  of 
  the 
  sea 
  and 
  floating 
  ice, 
  was 
  yet 
  unable 
  to 
  overlook 
  the 
  

   remarkable 
  fact 
  that 
  there 
  is 
  a 
  general 
  absence 
  of 
  marine 
  remains, 
  

   and 
  of 
  regular 
  beds 
  of 
  these 
  remains, 
  in 
  what 
  he 
  termed 
  the 
  Upper 
  

   Erratics, 
  not 
  only 
  in 
  Norfolk, 
  which 
  he 
  had 
  specially 
  studied, 
  but 
  

   also 
  in 
  every 
  district 
  of 
  England, 
  "Wales, 
  and 
  Ireland 
  he 
  had 
  ex- 
  

   amined*. 
  

  

  § 
  3. 
  Disappearance 
  of 
  the 
  Marine 
  Beds. 
  

  

  The 
  general 
  disappearance 
  of 
  the 
  glacial 
  marine 
  beds 
  over 
  most 
  

   of 
  Scotland 
  is 
  a 
  fact 
  difficult 
  to 
  explain, 
  except 
  upon 
  the 
  sup- 
  

   position 
  that 
  there 
  was 
  a 
  subsequent 
  occupation 
  of 
  the 
  ground 
  by 
  

   glaciers. 
  The 
  amount 
  of 
  submergence 
  is 
  on 
  this 
  account 
  very 
  diffi- 
  

   cult 
  to 
  determine 
  ; 
  for 
  the 
  evidence 
  of 
  the 
  sea's 
  presence 
  has 
  been 
  

   destroyed. 
  Several 
  geologists, 
  influenced 
  no 
  doubt 
  by 
  the 
  dis- 
  

   coveries 
  in 
  "Wales, 
  have 
  supposed, 
  and 
  perhaps 
  rightly, 
  that 
  the 
  sub- 
  

   mergence 
  reached 
  to 
  a 
  great 
  amount, 
  and 
  that 
  the 
  former 
  coast-line 
  

   must 
  at 
  one 
  time 
  have 
  been 
  2000 
  feet 
  above 
  the 
  present, 
  or 
  even 
  

   more. 
  But 
  when 
  we 
  ask 
  for 
  proof 
  we 
  get 
  little 
  that 
  is 
  satisfactory, 
  

   the 
  presence 
  of 
  far-travelled 
  boulders 
  at 
  great 
  heights 
  being 
  almost 
  

   the 
  only 
  fact 
  of 
  any 
  value 
  ; 
  and 
  this 
  may 
  admit 
  of 
  explanation 
  by 
  

   the 
  agency 
  of 
  land-ice. 
  Supposing, 
  however, 
  that 
  the 
  submergence 
  

   was 
  much 
  less, 
  and 
  reached 
  no 
  higher 
  than 
  say 
  500 
  feet 
  (which 
  no 
  

   one, 
  I 
  imagine, 
  will 
  consider 
  an 
  overestimate), 
  we 
  ought 
  to 
  find 
  

   marine 
  beds 
  far 
  more 
  widely 
  spread 
  than 
  we 
  do. 
  Eor 
  with 
  the 
  ex- 
  

   ception 
  of 
  some 
  of 
  the 
  flatter 
  ground 
  along 
  the 
  east 
  coast, 
  away 
  

   from 
  the 
  mountains, 
  and 
  here 
  and 
  there 
  over 
  the 
  Scottish 
  coal-field, 
  

   beds 
  containing 
  marine 
  arctic 
  fossils 
  are 
  unknown. 
  As 
  a 
  rule, 
  they 
  

   are 
  absent 
  from 
  all 
  the 
  Highland 
  valleys, 
  even 
  at 
  low 
  levels, 
  and, 
  

   generally 
  speaking, 
  are 
  not 
  to 
  be 
  met 
  with 
  near 
  hills, 
  and 
  from 
  the 
  

   country 
  to 
  the 
  west 
  of 
  the 
  Caledonian 
  canal 
  have 
  not 
  been 
  reported 
  

   at 
  all. 
  

  

  In 
  the 
  Clyde 
  district 
  many 
  shell-beds 
  are 
  known, 
  but 
  generally 
  

   near 
  the 
  shore, 
  and 
  very 
  little 
  above 
  the 
  present 
  reach 
  of 
  the 
  tide. 
  

   If 
  we 
  suppose 
  that 
  the 
  glaciers 
  again 
  occupied 
  the 
  surface 
  after 
  the 
  

   sea 
  withdrew, 
  it 
  will 
  afl'ord 
  a 
  better 
  explanation 
  of 
  the 
  disappear- 
  

   ance 
  of 
  the 
  marine 
  beds 
  than 
  any 
  other 
  I 
  can 
  think 
  of. 
  For 
  much 
  

   of 
  Ireland 
  and 
  England 
  the 
  same 
  hypothesis 
  seems 
  to 
  be 
  required. 
  

  

  In 
  Caithness 
  the 
  area 
  occupied 
  by 
  the 
  dark 
  grey 
  drift 
  containing 
  

   marine 
  shells 
  probably 
  marks 
  the 
  extent 
  of 
  ground 
  in 
  that 
  quarter 
  

   which 
  escaped 
  the 
  action 
  of 
  the 
  later 
  glaciers. 
  This 
  area 
  seems 
  to 
  

   be 
  bounded 
  by 
  the 
  hilly 
  ground 
  which 
  borders 
  the 
  plain 
  of 
  Caith- 
  

   ness 
  to 
  the 
  west 
  and 
  south. 
  In 
  the 
  latter 
  direction 
  it 
  stops 
  at 
  the 
  

   low 
  ridge 
  that 
  divides 
  the 
  water 
  of 
  Dunbeath 
  from 
  Berriedale 
  Glen, 
  

   into 
  which 
  the 
  grey 
  shelly 
  drift 
  does 
  not 
  enter. 
  Very 
  likely 
  the 
  

   grey 
  drift 
  may 
  have 
  been 
  cleared 
  out 
  of 
  the 
  lower 
  part 
  of 
  Berriedale 
  

   by 
  a 
  glacier 
  ; 
  for 
  some 
  patches 
  of 
  it 
  occur 
  about 
  the 
  mouth 
  of 
  the 
  

   * 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  vii. 
  p. 
  24, 
  1850. 
  

  

  