﻿1864.] 
  

  

  YOUNG 
  GLACIERS. 
  

  

  45^ 
  

  

  thick 
  Boulder-clay. 
  About 
  a 
  quarter 
  of 
  a 
  mile 
  below 
  the 
  house, 
  the 
  

   detritus 
  again 
  crosses 
  the 
  stream, 
  and 
  throughout 
  the 
  rest 
  of 
  its 
  

   course, 
  until 
  it 
  joins 
  Megget, 
  covers 
  both 
  banks, 
  shrinking 
  very 
  much, 
  

   however, 
  at 
  the 
  base 
  of 
  Dead- 
  for-Cauld, 
  whose 
  coomb-like 
  crags 
  

   form 
  a 
  recess 
  in 
  which 
  lies 
  a 
  thick 
  mass 
  of 
  Boulder-clay. 
  Here 
  the 
  

   moraine-matter 
  contains 
  an 
  unusual 
  number 
  of 
  scratched 
  stones, 
  

   derived 
  doubtless 
  from 
  the 
  older 
  glacier 
  deposit. 
  Craigdilly, 
  the 
  

   hill 
  on 
  the 
  east 
  side 
  of 
  this, 
  the 
  lowest 
  portion 
  of 
  Winterhope, 
  presents 
  

   towards 
  the 
  burn 
  a 
  bare 
  rocky 
  slope, 
  along 
  whose 
  base 
  the 
  detritus 
  

   is 
  limited 
  by 
  a 
  very 
  distinct 
  line, 
  and 
  by 
  a 
  series 
  of 
  moutonnee 
  

   surfaces 
  indicating 
  the 
  passage 
  of 
  ice 
  at 
  a 
  higher 
  level 
  than 
  that 
  of 
  

   the 
  detritus, 
  whose 
  interlacing 
  mounds 
  enclosing 
  small 
  pools 
  or 
  

   peat-pots 
  are 
  disposed 
  without 
  any 
  order. 
  

  

  Between 
  Firthy 
  Brig 
  Head 
  and 
  Loch 
  Craig 
  the 
  rock-terrace 
  for- 
  

   merly 
  mentioned 
  passes 
  northwards, 
  and 
  dips, 
  first 
  gently, 
  afterwards 
  

   rapidly, 
  into 
  Upper 
  Talla 
  Valley. 
  The 
  irregular 
  surface 
  of 
  the 
  ter- 
  

   race, 
  the 
  col, 
  and 
  the 
  slope 
  to 
  the 
  valley 
  are 
  covered 
  with 
  loose 
  grit- 
  

   fragments 
  and 
  sandy 
  debris 
  ; 
  the 
  glaciated 
  aspect 
  of 
  projecting 
  rocks 
  

   is 
  marked, 
  but 
  the 
  crumbling 
  nature 
  of 
  the 
  coarse 
  pebbly 
  grits 
  is 
  

   unfavourable 
  for 
  the 
  preservation 
  of 
  striations. 
  They 
  are 
  seen 
  only 
  

   in 
  one 
  place, 
  namely, 
  on 
  the 
  west 
  slope 
  a 
  little 
  north 
  of 
  the 
  March- 
  

   dyke, 
  on 
  a 
  smooth 
  surface 
  among 
  the 
  loose 
  blocks 
  which 
  strew 
  the 
  

   hill-side. 
  The 
  striae 
  run 
  down 
  the 
  valley 
  at 
  a 
  low 
  angle, 
  but 
  their 
  

   position, 
  about 
  50 
  feet 
  above 
  the 
  watershed, 
  renders 
  it 
  possible 
  that 
  

   they 
  may 
  belong 
  to 
  the 
  earlier 
  glaciation. 
  

  

  Fig. 
  3. 
  — 
  Sketch 
  of 
  Moraines 
  in 
  Upper 
  Talla 
  Valley, 
  seen 
  from 
  

  

  the 
  North*. 
  

  

  The 
  more 
  rapid 
  slope 
  terminates 
  in 
  a 
  marsh, 
  beneath 
  which 
  the 
  

   detritus 
  is 
  spread 
  evenly. 
  The 
  marsh 
  lies 
  in 
  an 
  expansion 
  oblique 
  

   to 
  the 
  valley, 
  in 
  fact 
  in 
  the 
  N.E. 
  strike 
  of 
  the 
  rocks, 
  since 
  it 
  is 
  hollowed 
  

   out 
  of 
  a 
  mass 
  of 
  softer 
  shales, 
  on 
  either 
  side 
  of 
  which 
  are 
  massive 
  

   grits, 
  namely, 
  abovo 
  at 
  the 
  slope, 
  and 
  below 
  at 
  Talla 
  Craig, 
  which 
  pro- 
  

  

  * 
  By 
  Archibald 
  Geikie, 
  Esq., 
  F.G-.S. 
  

  

  