﻿166 
  T. 
  F. 
  JAMIESON 
  ON 
  THE 
  EED 
  CLAY 
  

  

  which 
  they 
  were 
  frozen. 
  The 
  glaciation 
  of 
  the 
  rocks 
  near 
  the 
  

   Buchan 
  Ness 
  and 
  Murdoch 
  Head 
  may 
  perhaps 
  not 
  be 
  thought 
  suffi- 
  

   cient 
  to 
  render 
  it 
  imperative 
  to 
  call 
  in 
  the 
  agency 
  of 
  a 
  glacier,, 
  

   although 
  the 
  red 
  pebbly 
  clay 
  which 
  covers 
  them 
  is 
  unstratified 
  ; 
  but 
  

   at 
  the 
  Cove, 
  I 
  think, 
  the 
  appearances 
  are 
  more 
  conclusive 
  ; 
  for 
  the 
  red 
  

   Boulder-clay 
  there 
  is 
  very 
  hard 
  and 
  tough, 
  as 
  if 
  it 
  had 
  been 
  pressed 
  

   beneath 
  a 
  glacier. 
  I 
  therefore 
  incline 
  to 
  believe 
  that 
  the 
  glacier 
  

   really 
  did 
  advance 
  northward 
  along 
  the 
  coast 
  as 
  far 
  as 
  Aberdeen, 
  

   and 
  may 
  have 
  even 
  stretched 
  past 
  Peterhead. 
  

  

  In 
  regard 
  to 
  the 
  source 
  of 
  the 
  red 
  sediment, 
  it 
  must 
  be 
  kept 
  in 
  

   view 
  that 
  possibly 
  beds 
  of 
  Red 
  Sandstone 
  and 
  Conglomerate 
  may 
  

   occupy 
  the 
  present 
  sea-bottom 
  along 
  the 
  Aberdeenshire 
  coast 
  ; 
  for 
  

   some 
  little 
  outlier 
  patches 
  are 
  known 
  to 
  occur 
  at 
  Aberdeen, 
  although 
  

   too 
  small 
  to 
  be 
  shown 
  on 
  a 
  map 
  unless 
  of 
  a 
  large 
  scale. 
  

  

  Dr. 
  R. 
  Brown* 
  has 
  described 
  how 
  a 
  deposit 
  of 
  fine 
  clay, 
  just 
  

   like 
  what 
  we 
  have 
  in 
  Scotland, 
  is 
  at 
  present 
  in 
  course 
  of 
  formation 
  

   on 
  the 
  coast 
  of 
  Greenland 
  and 
  in 
  the 
  fiords 
  and 
  bays 
  of 
  that 
  country. 
  

   It 
  arises, 
  he 
  tells 
  us, 
  from 
  the 
  creamy 
  mud 
  produced 
  by 
  the 
  grinding- 
  

   down 
  of 
  the 
  mineral 
  matter 
  beneath 
  the 
  glacier, 
  and 
  is 
  carried 
  along 
  

   by 
  the 
  subglacial 
  torrents 
  issuing 
  from 
  the 
  ice. 
  The 
  action 
  of 
  the 
  

   waves 
  beating 
  upon 
  the 
  red 
  Boulder-clay 
  extruded 
  from 
  below 
  the 
  ice, 
  

   or 
  left 
  behind 
  it 
  when 
  it 
  retired, 
  would 
  no 
  doubt 
  give 
  rise 
  to 
  a 
  similar 
  

   fine 
  mud, 
  which 
  would 
  subside 
  in 
  the 
  deeper 
  depressions 
  where 
  there 
  

   was 
  still 
  water. 
  

  

  The 
  fact 
  of 
  the 
  ice 
  having 
  changed 
  its 
  line 
  of 
  movement 
  and 
  come 
  

   along 
  the 
  coast 
  from 
  the 
  south 
  is 
  wonderfully 
  in 
  accordance 
  with 
  

   the 
  views 
  of 
  Dr. 
  Croll, 
  who 
  in 
  his 
  paper 
  on 
  the 
  Caithness 
  drift 
  t 
  

   boldly 
  maintained 
  that, 
  owing 
  to 
  the 
  shallowness 
  of 
  the 
  sea 
  between 
  

   this 
  country 
  and 
  Norway, 
  the 
  Scandinavian 
  ice 
  would 
  not 
  be 
  able 
  to 
  

   float 
  and 
  break 
  up 
  into 
  bergs 
  like 
  that 
  of 
  Greenland, 
  but 
  would 
  be 
  

   obliged 
  to 
  spread 
  over 
  the 
  sea-bottom 
  and 
  advance 
  towards 
  Britain, 
  

   so 
  that 
  the 
  Scottish 
  ice 
  would 
  be 
  unable 
  to 
  move 
  out 
  to 
  the 
  eastward, 
  

   and 
  be 
  compelled 
  to 
  turn 
  along 
  the 
  coast 
  in 
  the 
  direction 
  it 
  seems 
  

   to 
  have 
  actually 
  taken. 
  

  

  5. 
  Organic 
  Conten 
  ts 
  of 
  the 
  Clay. 
  

  

  The 
  Eed 
  Clay 
  is 
  remarkably 
  devoid 
  of 
  remains 
  of 
  animal 
  and 
  

   vegetable 
  life. 
  It 
  is 
  rare 
  to 
  find 
  shells 
  in 
  it 
  ; 
  and 
  when 
  they 
  do 
  

   occur 
  it 
  is 
  always 
  very 
  scantily, 
  and 
  usually 
  in 
  broken 
  fragments. 
  

   I 
  have 
  never 
  seen 
  or 
  heard 
  of 
  any 
  sea-shells 
  in 
  the 
  clay 
  at 
  Aberdeen 
  

   itself, 
  although 
  some 
  of 
  the 
  pits 
  there 
  have 
  been 
  wrought 
  for 
  many 
  

   years. 
  But 
  they 
  sometimes 
  occur 
  at 
  a 
  pit 
  known 
  by 
  the 
  name 
  of 
  

   the 
  ' 
  Black 
  Dog,' 
  five 
  miles 
  north 
  of 
  that 
  town, 
  and 
  also 
  here 
  

   there 
  in 
  a 
  few 
  other 
  places. 
  The 
  most 
  common 
  species 
  are 
  Cy- 
  

   prma 
  islandica, 
  Astarte 
  borealis, 
  and 
  Saoeicava 
  sulcata, 
  large 
  form. 
  

   The 
  following 
  are 
  also 
  occasionally 
  met 
  with, 
  viz. 
  Astarte 
  elliptica, 
  

   Tellina 
  balthica, 
  Tellina 
  calcarea, 
  Pecten 
  islandicus, 
  Cardium 
  echi- 
  

  

  * 
  Quart. 
  Journ. 
  G-eol. 
  Soc. 
  1871, 
  vol. 
  xxvii. 
  p. 
  681. 
  

  

  t 
  Geol. 
  Mag. 
  vol. 
  vii. 
  p. 
  1, 
  May 
  1870 
  ; 
  see 
  also 
  ' 
  Climate 
  and 
  Time.' 
  

  

  