﻿168 
  t. 
  e. 
  jamieson 
  on 
  the 
  red 
  clay 
  

  

  6. 
  Progress 
  of 
  the 
  Submergence. 
  

  

  It 
  is 
  worthy 
  of 
  notice 
  that 
  there 
  is 
  no 
  evidence 
  at 
  the 
  bottom 
  of 
  

   the 
  clay 
  of 
  littoral 
  Mollusca 
  such 
  as 
  would 
  indicate 
  shore-conditions 
  

   at 
  the 
  commencement 
  of 
  the 
  submergence. 
  The 
  fine 
  red 
  mud 
  implies 
  

   deep, 
  or 
  at 
  least 
  quiet 
  water 
  ; 
  and 
  as 
  a 
  rule 
  it 
  lies 
  immediately 
  upon 
  

   the 
  top 
  of 
  the 
  grey 
  Boulder-clay, 
  without 
  the 
  intervention 
  of 
  any 
  

   beach-gravel 
  or 
  sand 
  between 
  them, 
  as 
  if 
  still 
  water 
  of 
  some 
  depth 
  

   had 
  at 
  once 
  taken 
  the 
  place 
  of 
  the 
  glacier. 
  This 
  may 
  be 
  explained 
  

   by 
  supposing 
  that 
  at 
  the 
  beginning 
  of 
  the 
  depression 
  the 
  glacier 
  still 
  

   occupied 
  the 
  surface 
  and 
  did 
  not 
  break 
  up 
  until 
  a 
  considerable 
  

   amount 
  of 
  submergence 
  had 
  occurred. 
  In 
  this 
  way 
  deep 
  water 
  

   would 
  take 
  the 
  place 
  of 
  the 
  ice 
  as 
  soon 
  as 
  it 
  floated 
  off 
  the 
  bottom 
  ; 
  

   and 
  the 
  red 
  mud 
  would 
  then 
  settle 
  down 
  upon 
  the 
  exposed 
  surface 
  

   of 
  the 
  grey 
  Boulder-clay. 
  

  

  During 
  the 
  time 
  the 
  glaciers 
  attained 
  their 
  full 
  development 
  there 
  

   might 
  have 
  been 
  a 
  considerable 
  depression 
  of 
  the 
  land 
  going 
  on 
  ; 
  but 
  

   if 
  the 
  whole 
  surface 
  of 
  Scotland 
  was 
  covered 
  with 
  thick 
  ice, 
  the 
  sea 
  

   would 
  not 
  gain 
  admission 
  to 
  the 
  depressed 
  tracts 
  until 
  the 
  ice 
  was 
  

   removed. 
  In 
  the 
  Antarctic 
  continent 
  and 
  some 
  parts 
  of 
  Greenland 
  

   a 
  similar 
  state 
  of 
  matters 
  prevails. 
  The 
  glacier 
  occupies 
  the 
  sea- 
  

   bottom, 
  excluding 
  the 
  salt 
  water, 
  and 
  embraces 
  many 
  of 
  the 
  islands, 
  

   insomuch 
  that 
  it 
  is 
  difficult 
  to 
  know 
  whether 
  the 
  land 
  is 
  continental 
  

   or 
  consists 
  of 
  a 
  group 
  of 
  islands 
  soldered 
  together 
  by 
  ice. 
  

  

  The 
  evidence 
  in 
  Scotland 
  seems 
  to 
  point 
  to 
  a 
  somewhat 
  similar 
  

   condition. 
  The 
  whole 
  country 
  seems 
  at 
  one 
  time 
  to 
  have 
  been 
  thickly 
  

   clad 
  with 
  ice; 
  and 
  I 
  believe 
  the 
  depression 
  or 
  submergence 
  began 
  

   when 
  such 
  was 
  the 
  state 
  of 
  affairs. 
  But 
  the 
  beds 
  of 
  fine 
  marine 
  clay 
  

   must 
  have 
  been 
  deposited 
  at 
  a 
  later 
  stage, 
  after 
  the 
  ice 
  began 
  to 
  

   give 
  way. 
  The 
  thinnest 
  ice 
  would 
  yield 
  soonest 
  ; 
  and 
  we 
  might 
  

   therefore 
  expect 
  it 
  would 
  be 
  there 
  the 
  sea-water 
  would 
  make 
  its 
  

   first 
  appearance. 
  

  

  The 
  glacier-ice 
  seems 
  to 
  have 
  been 
  less 
  heavily 
  developed 
  on 
  that 
  

   north-eastern 
  angle 
  of 
  Scotland 
  which 
  lies 
  between 
  the 
  Moray 
  Firth 
  

   and 
  the 
  Firth 
  of 
  Forth 
  than 
  elsewhere 
  ; 
  and 
  we 
  may 
  therefore 
  suppose 
  

   that 
  it 
  would 
  melt 
  away 
  most 
  quickly 
  in 
  that 
  quarter. 
  The 
  sea- 
  

   water 
  would 
  therefore 
  probably 
  establish 
  itself 
  first 
  in 
  the 
  neigh- 
  

   bourhood 
  of 
  Peterhead 
  and 
  Fraserburgh, 
  and 
  thence 
  cueep 
  south 
  and 
  

   west 
  along 
  the 
  coast 
  as 
  the 
  ice 
  gradually 
  broke 
  up. 
  But 
  when 
  the 
  

   ice 
  disappeared, 
  it 
  would 
  seem 
  that 
  either 
  the 
  land 
  began 
  to 
  rise 
  

   again 
  or 
  the 
  sea-level 
  began 
  to 
  sink, 
  so 
  that 
  the 
  submergence 
  became 
  

   less 
  and 
  less 
  and 
  gradually 
  came 
  to 
  an 
  end. 
  The 
  submergence 
  seems 
  

   to 
  have 
  followed 
  close 
  upon 
  the 
  presence 
  of 
  the 
  ice, 
  and 
  not 
  to 
  have 
  

   endured 
  long 
  after 
  the 
  ice 
  vanished. 
  This 
  appears 
  to 
  have 
  been 
  the 
  

   case 
  not 
  only 
  in 
  Scotland, 
  but 
  also 
  in 
  other 
  countries 
  ; 
  so 
  that 
  it 
  is 
  

   difficult 
  to 
  avoid 
  the 
  conclusion 
  that 
  there 
  must 
  have 
  been 
  some 
  

   intimate 
  connexion 
  between 
  the 
  two 
  events. 
  

  

  As 
  the 
  submergence 
  proceeded 
  the 
  glacier 
  seems 
  to 
  have 
  gradually 
  

   retired, 
  sending 
  out 
  red 
  mud 
  all 
  along 
  its 
  margin. 
  This 
  recession 
  

   went 
  on 
  until 
  the 
  ice 
  left 
  the 
  Aberdeenshire 
  coast 
  altogether 
  and 
  

  

  