﻿I. 
  F. 
  JA3IIES0N 
  OX 
  THE 
  GLACIAL 
  PERIOD 
  IX 
  NORTH 
  BRITAIN. 
  317 
  

  

  26. 
  On 
  the 
  Last 
  Stage 
  of 
  the 
  Glacial 
  Period 
  in 
  North 
  Britain. 
  

   By 
  T. 
  E. 
  Jamieson, 
  Esq., 
  E.G.S. 
  (Read 
  May 
  27, 
  1874.) 
  

  

  Contents. 
  

  

  § 
  1. 
  Introductory. 
  

  

  | 
  2. 
  General 
  features 
  of 
  the 
  surface. 
  

  

  § 
  3. 
  Disappearance 
  of 
  the 
  marine 
  beds. 
  

  

  § 
  4. 
  Moraines 
  at 
  low 
  levels. 
  

  

  § 
  5. 
  Freshness 
  of 
  the 
  glacial 
  markings. 
  

  

  § 
  6. 
  Kaims, 
  Eskers, 
  &c. 
  

  

  § 
  7. 
  Gravel 
  terraces. 
  

  

  § 
  8. 
  Comparative 
  glaciation 
  of 
  east 
  

  

  and 
  west 
  coasts. 
  

   § 
  9. 
  Conclusion. 
  

  

  § 
  1. 
  Introductory. 
  

  

  In 
  Scotland 
  we 
  seem 
  to 
  have 
  at 
  least 
  three 
  well-defined 
  stages 
  in 
  the 
  

   history 
  of 
  the 
  Glacial 
  period, 
  viz. 
  : 
  — 
  1st, 
  the 
  great 
  early 
  glaciation 
  by 
  

   land 
  ice 
  ; 
  2nd, 
  the 
  period 
  represented 
  by 
  the 
  glacial 
  marine 
  beds, 
  

   containing 
  remains 
  of 
  arctic 
  mollusca, 
  when 
  much 
  of 
  the 
  country 
  

   was 
  covered 
  by 
  the 
  sea 
  ; 
  and, 
  3rd, 
  what 
  I 
  shall 
  call 
  the 
  time 
  of 
  the 
  

   later 
  glaciers. 
  It 
  is 
  to 
  the 
  history 
  of 
  this 
  last 
  part 
  that 
  the 
  follow- 
  

   ing 
  pages 
  are 
  chiefly 
  devoted. 
  

  

  During 
  the 
  first 
  stage 
  glacial 
  conditions 
  seem 
  to 
  have 
  attained 
  

   their 
  maximum, 
  and 
  the 
  whole 
  of 
  Scotland 
  appears 
  to 
  have 
  been 
  

   covered 
  for 
  a 
  long 
  time 
  with 
  snow 
  and 
  thick 
  ice, 
  as 
  North 
  Greenland 
  

   is 
  at 
  the 
  present 
  day. 
  An 
  opinion 
  has 
  occasionally 
  been 
  expressed 
  

   that 
  it 
  was 
  the 
  polar 
  ice 
  which 
  at 
  this 
  time 
  spread 
  in 
  a 
  continuous 
  

   mass 
  from 
  the 
  arctic 
  circle 
  over 
  a 
  considerable 
  part 
  of 
  the 
  northern 
  

   hemisphere, 
  covering 
  much 
  of 
  the 
  north 
  of 
  Europe 
  as 
  well 
  as 
  most 
  

   of 
  Britain. 
  I 
  cannot 
  say 
  that 
  I 
  have 
  met 
  with 
  evidence 
  of 
  a 
  mass 
  

   of 
  glacier-ice 
  from 
  the 
  polar 
  regions 
  having 
  moved 
  over 
  the 
  district 
  

   with 
  which 
  I 
  am 
  acquainted. 
  On 
  the 
  contrary, 
  there 
  are 
  facts 
  

   which 
  seem 
  to 
  me 
  inconsistent 
  with 
  such 
  a 
  notion. 
  One 
  of 
  these 
  is 
  

   the 
  occurrence 
  of 
  extensive 
  beds 
  of 
  chalk-flints 
  along 
  the 
  crest 
  of 
  a 
  

   range 
  of 
  low 
  hills 
  running 
  for 
  six 
  or 
  seven 
  miles 
  inland 
  from 
  Peter- 
  

   head. 
  

  

  These 
  beds 
  of 
  loose 
  flint 
  pebbles, 
  lying, 
  as 
  they 
  do, 
  on 
  the 
  very 
  

   top 
  of 
  a 
  range 
  of 
  bare 
  exposed 
  hills 
  at 
  altitudes 
  of 
  from 
  250 
  to 
  

   370 
  feet, 
  must 
  have 
  inevitably 
  been 
  swept 
  off 
  by 
  a 
  great 
  mass 
  of 
  

   glacier-ice 
  moving 
  over 
  them 
  from 
  any 
  quarter. 
  It 
  is 
  true 
  they 
  

   have 
  been 
  carried 
  away 
  here 
  and 
  there, 
  and 
  cut 
  off 
  abruptly 
  in 
  cer- 
  

   tain 
  directions, 
  as 
  if 
  by 
  the 
  glacier-ice 
  of 
  the 
  adjoining 
  district 
  ; 
  but 
  

   for 
  a 
  distance 
  of 
  several 
  miles 
  they 
  lie 
  thickly 
  along 
  the 
  very 
  top 
  of 
  

   the 
  ridge. 
  Their 
  quantity, 
  and 
  the 
  extent 
  of 
  ground 
  they 
  cover, 
  

   forbid 
  us 
  from 
  supposing 
  that 
  they 
  have 
  been 
  drifted 
  from 
  some 
  

   foreign 
  region 
  ; 
  but 
  assuming 
  that 
  they 
  are 
  native 
  to 
  the 
  locality, 
  it 
  

   may 
  still 
  be 
  said 
  that 
  they 
  were 
  not 
  in 
  the 
  state 
  of 
  loose 
  pebbles 
  at 
  

   the 
  time 
  of 
  the 
  ice, 
  but 
  may 
  have 
  been 
  imbedded 
  in 
  strata 
  of 
  solid 
  

   chalk, 
  which 
  have 
  since 
  been 
  dissolved. 
  This, 
  however, 
  I 
  consider 
  

   a 
  very 
  improbable 
  supposition. 
  

  

  This 
  ridge, 
  although 
  it 
  attains 
  the 
  altitude 
  of 
  only 
  a 
  few 
  hundred 
  

   feet, 
  is, 
  nevertheless, 
  higher 
  than 
  any 
  ground 
  immediately 
  to 
  the 
  

  

  