﻿458 
  PKOCEEDIXGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [June 
  22, 
  

  

  jects 
  into 
  the 
  hollow, 
  its 
  base 
  lapped 
  by 
  mounds 
  increasing 
  in 
  coarse- 
  

   ness 
  until 
  it 
  is 
  difficult 
  to 
  distinguish 
  them 
  from 
  rock 
  in 
  place. 
  

  

  Prom 
  the 
  Craigs 
  the 
  valley 
  for 
  a 
  mile 
  contains 
  a 
  fine 
  series 
  

   of 
  moraine 
  mounds 
  and 
  ridges, 
  the 
  latter 
  on 
  the 
  west 
  side 
  parallel 
  

   to 
  the 
  stream 
  ; 
  while 
  on 
  the 
  east 
  side, 
  though 
  the 
  mounds 
  are 
  for 
  

   the 
  most 
  part 
  irregularly 
  disposed, 
  enclosing 
  hollows 
  lodging 
  pools 
  of 
  

   water 
  or 
  small 
  peat-pots 
  into 
  which 
  have 
  rolled 
  a 
  few 
  of 
  the 
  loose 
  

   blocks 
  which 
  abundantly 
  strew 
  the 
  surface, 
  there 
  may 
  be 
  traced 
  a 
  

   few 
  curved 
  lines 
  of 
  heaps 
  stopping 
  short 
  of 
  the 
  burn, 
  as 
  if 
  only 
  half 
  

   of 
  several 
  frontal 
  moraines 
  had 
  been 
  formed. 
  

  

  The 
  east 
  wall 
  of 
  the 
  valley 
  is 
  formed 
  by 
  the 
  heights 
  descending 
  

   from 
  Loch 
  Craig, 
  whose 
  steep 
  faces 
  run 
  straight 
  north, 
  and 
  at 
  

   Wood 
  Brae 
  turn 
  abruptly 
  east 
  into 
  Upper 
  Megget. 
  The 
  west 
  wall 
  

   slopes 
  down 
  from 
  Talla 
  Craigs, 
  and 
  some 
  distance 
  above 
  Wood 
  Brae 
  

   turns 
  west 
  towards 
  Carlavin 
  Hill. 
  The 
  open 
  space 
  left 
  by 
  the 
  

   divergence 
  of 
  these 
  slopes 
  is 
  bounded 
  by 
  the 
  wide 
  base 
  of 
  Pan's 
  Law 
  

   (the 
  southern 
  extremity 
  of 
  Broad 
  Law 
  range), 
  which 
  eastward 
  forms 
  

   with 
  AVood 
  Brae 
  the 
  throat 
  of 
  Megget, 
  and 
  westward 
  with 
  Carlavin 
  

   the 
  pass 
  leading 
  to 
  Lower 
  Talla. 
  This 
  space 
  is 
  filled 
  with 
  a 
  peat- 
  

   covered 
  mass 
  of 
  detritus 
  which, 
  directly 
  opposite 
  the 
  mouth 
  of 
  Upper 
  

   Talla, 
  reaches 
  to 
  the 
  1500-ft. 
  line, 
  sloping 
  from 
  thence 
  east, 
  west, 
  

   and 
  south. 
  Descending 
  Talla, 
  the 
  natural 
  course 
  of 
  the 
  stream 
  

   seems 
  to 
  be 
  along 
  the 
  foot 
  of 
  Wood 
  Brae 
  into 
  Megget 
  : 
  it 
  follows, 
  

   however, 
  the 
  curve 
  of 
  its 
  western 
  wall, 
  and 
  passes 
  towards 
  Carlavin, 
  

   while 
  the 
  Megget 
  has 
  a 
  separate 
  origin 
  200 
  yards 
  to 
  the 
  north, 
  a 
  

   narrow 
  neck 
  of 
  peat-moss 
  and 
  detritus 
  little 
  elevated 
  above 
  either 
  

   stream 
  dividing 
  them. 
  The 
  spit 
  of 
  moraine-matter 
  resting 
  on 
  Fan's 
  

   Law, 
  and 
  pointing 
  up 
  Talla, 
  is 
  a 
  repetition 
  of 
  what 
  was 
  described 
  

   at 
  Loch 
  Skene, 
  namely, 
  it 
  indicates 
  the 
  point 
  of 
  bifurcation 
  of 
  the 
  

   ice-stream, 
  when, 
  arrested 
  by 
  the 
  opposing 
  hill, 
  one 
  branch 
  passed 
  

   down 
  Megget, 
  the 
  other 
  westwards 
  towards 
  Lower 
  Talla. 
  In 
  the 
  

   concavity 
  of 
  the 
  bend, 
  on 
  Wood 
  Brae, 
  are 
  several 
  lateral 
  moraines 
  

   rising 
  above 
  the 
  level 
  of 
  the 
  detritus 
  on 
  the 
  opposite 
  side 
  ; 
  the 
  

   lowest 
  of 
  these 
  ridges, 
  of 
  great 
  beauty 
  and 
  perfection, 
  is 
  about 
  1000 
  

   feet 
  in 
  length. 
  From 
  this 
  point 
  the 
  detritus 
  thins 
  out, 
  lying 
  

   between 
  slopes 
  of 
  Boulder- 
  clay, 
  which 
  on 
  the 
  north 
  side 
  is 
  of 
  great 
  

   thickness. 
  At 
  Wylie's 
  Brae 
  it 
  again 
  swells 
  out 
  and 
  forms 
  a 
  con- 
  

   fused 
  series 
  of 
  mounds 
  which, 
  joined 
  at 
  Megget 
  Head 
  by 
  the 
  detritus 
  

   descending 
  from 
  a 
  valley 
  to 
  the 
  north, 
  extend 
  below 
  the 
  junction 
  of 
  

   Winterhope 
  and 
  Megget 
  waters. 
  The 
  common 
  stream 
  soon 
  enters 
  

   a 
  broad 
  alluvial 
  plain, 
  where 
  the 
  moraines 
  are 
  lost, 
  the 
  sides 
  of 
  the 
  

   valley 
  being 
  lined 
  by 
  Boulder-clay. 
  

  

  Westwards, 
  the 
  detritus 
  passes 
  to 
  the 
  head 
  of 
  Talla 
  Linns, 
  showing 
  

   one 
  or 
  two 
  obscure 
  mounds, 
  which 
  seem 
  to 
  have 
  crossed 
  the 
  stream. 
  

   The 
  declivity 
  is 
  covered 
  by 
  detritus, 
  limited 
  above 
  on 
  Carlavin 
  by 
  a 
  

   line 
  of 
  rocky 
  moutonnees. 
  At 
  the 
  foot 
  of 
  the 
  hill 
  the 
  common 
  

   alluvium 
  of 
  Talla 
  and 
  Gameshope 
  occupies 
  the 
  floor 
  of 
  the 
  valley, 
  

   and 
  a 
  short 
  way 
  below 
  the 
  Shepherd's 
  House 
  Boulder-clay 
  is 
  thick 
  

   on 
  the 
  right 
  bank. 
  The 
  characteristics 
  of 
  glacier-debris 
  are 
  well 
  

   marked 
  throughout 
  these 
  valleys, 
  and 
  are 
  admirably 
  seen 
  in 
  several 
  

  

  