﻿THEORY 
  OF 
  L 
  AXE-BASINS. 
  483 
  

  

  seite," 
  and 
  so 
  should 
  slope 
  gently 
  upwards 
  from 
  the 
  water. 
  Again, 
  

   the 
  whole 
  fall 
  of 
  the 
  valley 
  from 
  the 
  Maloya 
  Kulm 
  to 
  the 
  St.-Moritzer 
  

   See, 
  a 
  distance 
  of 
  nearly 
  ten 
  miles, 
  is 
  only 
  145', 
  and 
  from 
  the 
  head 
  

   of 
  the 
  Silser 
  See, 
  which 
  extends 
  almost 
  to 
  the 
  Kulm, 
  barely 
  100', 
  a 
  

   fall 
  of 
  about 
  1 
  in 
  500, 
  which 
  could 
  not 
  give 
  much 
  excavating 
  power. 
  

   In 
  a 
  word, 
  though 
  the 
  lake 
  is 
  a 
  true 
  rock-basin, 
  the 
  physical 
  fea- 
  

   tures 
  of 
  this 
  district 
  in 
  no 
  way 
  lend 
  themselves 
  to 
  a 
  theory 
  of 
  

   glacier 
  erosion 
  ; 
  they 
  rather 
  seem 
  to 
  be 
  preglacial 
  in 
  their 
  age, 
  and 
  

   to 
  have 
  been 
  only 
  very 
  superficially 
  modified 
  by 
  ice-action. 
  

  

  We 
  proceed 
  now 
  to 
  the 
  head 
  of 
  the 
  Silser 
  See, 
  which, 
  as 
  being 
  

   obviously 
  the 
  most 
  important 
  part 
  of 
  the 
  district, 
  I 
  examined 
  very 
  

   carefully. 
  The 
  present 
  head 
  of 
  the 
  lake 
  is 
  a 
  marshy 
  plain, 
  sur- 
  

   rounded 
  by 
  alluvial 
  terraces, 
  which 
  are 
  about 
  20' 
  high, 
  and 
  often 
  

   rest 
  on 
  rock. 
  The 
  results 
  of 
  my 
  observations 
  were 
  as 
  follows 
  : 
  — 
  

  

  1. 
  The 
  watershed 
  of 
  the 
  Maloya 
  Pass 
  is 
  formed 
  by 
  a 
  low 
  rocky 
  

   iceworn 
  barrier 
  which 
  falls 
  down 
  in 
  fine 
  precipices 
  to 
  the 
  Yal 
  

   Bregaglia. 
  

  

  2. 
  The 
  various 
  glens 
  which 
  come 
  down 
  to 
  the 
  Silser 
  See 
  show 
  

   signs 
  of 
  local 
  glacier-action 
  down 
  to 
  very 
  near 
  the 
  water's 
  edge 
  ; 
  but 
  

   all 
  their 
  principal 
  physical 
  features 
  appear 
  to 
  be 
  anterior 
  to 
  the 
  

   glacial 
  epoch. 
  

  

  3. 
  The 
  principal 
  affluents 
  to 
  the 
  main 
  Inn 
  Glacier 
  must 
  formerly 
  

   have 
  been 
  from 
  the 
  Yal 
  Pex 
  and 
  the 
  Val 
  Fedoz, 
  the 
  general 
  direc- 
  

   tions 
  of 
  which 
  make 
  angles 
  of 
  about 
  70 
  c 
  with 
  the 
  axis 
  of 
  the 
  Inn 
  

   valley; 
  yet 
  there 
  is 
  no 
  recess 
  of 
  the 
  opposite 
  shore 
  to 
  correspond 
  

   with 
  the 
  entrance 
  of 
  these 
  ; 
  and 
  they 
  cannot 
  have 
  materially 
  

   deepened 
  the 
  lake, 
  because 
  the 
  debris 
  from 
  them 
  has 
  converted 
  it 
  in 
  

   the 
  one 
  case 
  into 
  dry 
  land, 
  in 
  the 
  other 
  has 
  made 
  a 
  considerable 
  

   delta. 
  

  

  4. 
  In 
  the 
  rocky 
  barrier 
  spoken 
  of 
  above 
  is 
  a 
  gorge 
  which 
  shows 
  

   that 
  the 
  lake, 
  or 
  the 
  glacier 
  occupying 
  its 
  place, 
  formerly 
  discharged 
  

   its 
  waters 
  into 
  the 
  Val 
  Bregaglia. 
  

  

  5. 
  There 
  are 
  numerous 
  perched 
  blocks 
  on 
  this 
  barrier 
  and 
  several 
  

   moraines, 
  some 
  being 
  very 
  large. 
  These 
  extend 
  from 
  the 
  base 
  of 
  

   the 
  Pizzo 
  della 
  Margna 
  in 
  a 
  general 
  direction 
  of 
  W. 
  20° 
  N. 
  to 
  close 
  

   to 
  the 
  barrier. 
  One 
  of 
  the 
  largest 
  forms 
  the 
  present 
  actual 
  water- 
  

   parting. 
  On 
  the 
  southern 
  side 
  of 
  this 
  are 
  some 
  marshy 
  flats 
  inter- 
  

   rupted 
  by 
  moraines, 
  the 
  waters 
  of 
  which 
  are 
  discharged 
  by 
  the 
  

   gorge 
  (4). 
  

  

  6. 
  Many 
  of 
  the 
  blocks, 
  perched 
  on 
  the 
  barrier 
  and 
  in 
  the 
  moraines, 
  

   are 
  a 
  fine 
  porphyritic 
  granite. 
  I 
  found 
  no 
  more 
  erratics 
  of 
  this 
  kind 
  

   after 
  reaching 
  the 
  first 
  glen 
  from 
  the 
  Piz 
  Lunghino. 
  They 
  come 
  

   from 
  the 
  Val 
  Forno, 
  the 
  floor 
  of 
  which 
  valley 
  is 
  nearly 
  on 
  the 
  level 
  

   of 
  the 
  Maloya 
  Pass, 
  and 
  descends 
  very 
  rapidly 
  into 
  the 
  head 
  of 
  the 
  

   Val 
  Bregaglia. 
  The 
  rocks 
  near 
  the 
  Maloya-Kulm 
  Hotel 
  are 
  also 
  

   glaciated 
  by 
  ice 
  that 
  has 
  moved 
  from 
  the 
  Val 
  Porno. 
  

  

  7. 
  The 
  glaciers 
  about 
  the 
  head 
  of 
  the 
  lake 
  are 
  all 
  connected 
  with 
  

   the 
  existing 
  valley- 
  system. 
  That 
  from 
  the 
  Val 
  Porno 
  actually 
  

   swept 
  over 
  and, 
  as 
  it 
  were, 
  rested 
  an 
  elbow 
  on 
  the 
  top 
  of 
  the 
  Pass. 
  

   The 
  glen 
  under 
  the 
  Piz 
  Lunghino, 
  which 
  joins 
  the 
  lake 
  a 
  short 
  way 
  

  

  