﻿GEAVEL 
  BEDS 
  OF 
  ABEEDEENSHIEE. 
  149 
  

  

  smooth 
  finely-rounded 
  pebbles, 
  such 
  as 
  we 
  see 
  on 
  a 
  sea-beach, 
  

   although 
  a 
  few 
  small 
  ones 
  of 
  this 
  sort 
  may 
  be 
  found. 
  The 
  whole 
  of 
  

   the 
  materials 
  — 
  the 
  fine 
  sand, 
  gravel, 
  pebbles, 
  and 
  larger 
  stones 
  — 
  may 
  

   occur 
  in 
  any 
  relation 
  to 
  each 
  other, 
  there 
  being 
  no 
  regular 
  order 
  or 
  

   succession. 
  Generally 
  the 
  materials 
  are 
  well 
  washed, 
  as 
  if 
  they 
  had 
  

   been 
  tossed 
  about 
  in 
  water; 
  but 
  occasionally 
  the 
  gravel 
  is 
  of 
  a 
  

   muddier 
  character, 
  and 
  sometimes 
  passes 
  into 
  an 
  unstratified 
  heap 
  of 
  

   coarse 
  stony 
  rubbish. 
  As 
  a 
  rule, 
  however, 
  the 
  materials 
  are 
  so 
  inco- 
  

   herent 
  that, 
  when 
  excavations 
  are 
  made, 
  the 
  stuff 
  is 
  continually 
  

   tumbling 
  down, 
  and 
  no 
  clear 
  section 
  remains 
  long 
  exposed. 
  It 
  is 
  

   exceedingly 
  rare 
  to 
  find 
  any 
  trace 
  of 
  glacial 
  scratching 
  on 
  the 
  

   stones 
  — 
  so 
  much 
  so, 
  that 
  I 
  at 
  one 
  time 
  thought 
  it 
  never 
  occurred 
  ; 
  

   but 
  I 
  have 
  recently 
  found 
  at 
  least 
  one 
  instance 
  of 
  it, 
  although 
  in 
  

   this 
  case 
  the 
  scratches 
  Avere 
  nearly 
  effaced. 
  The 
  absence 
  of 
  the 
  

   glacial 
  striae 
  is 
  the 
  more 
  remarkable, 
  seeing 
  that 
  the 
  mineral 
  quality 
  

   of 
  many 
  of 
  the 
  stones 
  is 
  well 
  adapted 
  for 
  receiving 
  and 
  exhibiting 
  

   them. 
  

  

  Small 
  pieces 
  of 
  broken 
  shells, 
  very 
  much 
  worn, 
  are 
  pretty 
  uni- 
  

   formly 
  but 
  very 
  scantily 
  dispersed 
  through 
  these 
  ridges, 
  from 
  the 
  

   very 
  surface 
  down 
  to 
  the 
  bottom 
  as 
  far 
  as 
  the 
  excavations 
  have 
  

   gone 
  ; 
  and 
  they 
  are 
  often 
  as 
  frequent 
  on 
  the 
  surface, 
  I 
  think, 
  as 
  in 
  

   the 
  interior. 
  This 
  is 
  a 
  circumstance 
  of 
  some 
  interest, 
  as 
  the 
  un- 
  

   fossiliferous 
  character 
  of 
  many 
  eskers 
  and 
  gravel-beds 
  has 
  been 
  

   attributed 
  to 
  the 
  agency 
  of 
  rainwater 
  &c. 
  dissolving 
  the 
  shells 
  they 
  

   had 
  once 
  contained. 
  The 
  shelly 
  material 
  occurs 
  generally 
  in 
  the 
  

   form 
  of 
  fine 
  pounded 
  debris 
  and 
  small 
  worn 
  crumbs, 
  with 
  here 
  and 
  

   there 
  a 
  larger 
  bit, 
  generally 
  a 
  hinge 
  of 
  Cyprina, 
  Aslarte, 
  or 
  Venus. 
  

   The 
  bottom 
  of 
  the 
  gravel 
  has 
  not 
  been 
  reached 
  anywhere 
  in 
  the 
  

   Kippet 
  Hills, 
  so 
  far 
  as 
  I 
  know 
  ; 
  I 
  am 
  therefore 
  unable 
  to 
  say 
  what 
  

   it 
  rests 
  upon 
  there 
  ; 
  but 
  it 
  is 
  covered 
  in 
  some 
  places 
  by 
  a 
  mass 
  of 
  

   red 
  clay, 
  in 
  which 
  some 
  ice-scratched 
  stones 
  are 
  occasionally 
  to 
  be 
  

   found. 
  This 
  clay 
  seems 
  to 
  have 
  suffered 
  denudation, 
  and 
  is 
  absent 
  

   along 
  the 
  crest 
  of 
  most 
  of 
  the 
  ridge, 
  although 
  a 
  patch 
  of 
  it 
  may 
  here 
  

   and 
  there 
  be 
  found 
  ; 
  on 
  the 
  gentler 
  undulations 
  it 
  is 
  more 
  frequent. 
  

   The 
  steep 
  slope 
  of 
  25° 
  to 
  35° 
  which 
  occurs 
  along 
  a 
  part 
  of 
  the 
  Kippet 
  

   ridge, 
  near 
  the 
  Loch 
  of 
  Slains, 
  appears 
  to 
  be 
  due 
  to 
  some 
  action 
  

   that 
  has 
  taken 
  place 
  subsequent 
  to 
  the 
  deposition 
  of 
  the 
  red 
  clay 
  ; 
  

   but 
  it 
  is 
  also 
  evident 
  that 
  the 
  clay 
  reposes 
  on 
  an 
  irregular, 
  undu- 
  

   lating, 
  or 
  ridgy 
  surface 
  of 
  gravel, 
  and 
  that 
  much 
  of 
  the 
  gravel 
  must 
  

   have 
  had 
  a 
  inoundy 
  outline 
  when 
  the 
  clay 
  first 
  lodged 
  on 
  it. 
  

  

  In 
  addition 
  to 
  the 
  shells 
  these 
  gravel-beds 
  are 
  distinguished 
  by 
  

   containing 
  many 
  pieces 
  of 
  grey 
  and 
  yellow 
  limestone 
  and 
  calcareous 
  

   shale, 
  which 
  look 
  as 
  if 
  they 
  were 
  derived 
  from 
  rocks 
  of 
  the 
  Permian 
  or 
  

   Oolitic 
  formations. 
  And 
  I 
  find 
  all 
  over 
  Slains 
  and 
  Cruden, 
  where- 
  

   ever 
  these 
  shells 
  occur, 
  that 
  this 
  limestone 
  debris 
  invariably 
  occurs 
  

   along 
  with 
  them 
  ; 
  so 
  that 
  it 
  has 
  apparently 
  formed 
  part 
  of 
  the 
  mate- 
  

   rial 
  which 
  composed 
  the 
  original 
  strata 
  that 
  furnished 
  the 
  shells. 
  

   I 
  have 
  seen 
  no 
  limestone-rocks 
  of 
  this 
  nature 
  in 
  Aberdeenshire, 
  

   and 
  am 
  unable 
  to 
  point 
  out 
  the 
  source 
  whence 
  the 
  fragments 
  have 
  

   been 
  derived. 
  In 
  addition 
  to 
  the 
  limestone 
  debris, 
  bits 
  of 
  red 
  and 
  

  

  