﻿86 
  PROF. 
  T. 
  G. 
  BONNET 
  ON 
  TWO 
  TRAVERSES 
  OE 
  THE 
  

  

  which 
  rise 
  just 
  south 
  of 
  the 
  line 
  for 
  some 
  distance 
  on 
  either 
  side 
  of 
  the 
  

   Toblacher 
  plateau. 
  This 
  is 
  the 
  singular, 
  flat, 
  drift-covered 
  watershed 
  

   between 
  streams 
  which 
  drain 
  on 
  the 
  west 
  to 
  the 
  Adriatic, 
  on 
  the 
  

   east 
  to 
  the 
  Black 
  Sea. 
  

  

  (y) 
  Lienz 
  to 
  MiUersill. 
  

  

  At 
  Lienz 
  we 
  turned 
  northward, 
  ascending 
  the 
  valley 
  of 
  the 
  Isel, 
  

   a 
  broad 
  strong 
  stream 
  which 
  forms 
  an 
  important 
  tributary 
  of 
  the 
  

   Drave. 
  A 
  short 
  distance 
  above 
  the 
  town, 
  by 
  the 
  bridge 
  over 
  the 
  

   Isel, 
  is 
  a 
  knoll 
  of 
  " 
  Thonglimmerschiefer" 
  a 
  somewhat 
  banded, 
  lead- 
  

   coloured 
  schist, 
  tolerably 
  hard 
  and 
  strong, 
  the 
  structure 
  dipping 
  at 
  

   a 
  low 
  angle 
  to 
  the 
  E.N.E. 
  This, 
  as 
  T 
  wrote 
  in 
  my 
  diary, 
  " 
  is 
  a 
  rock 
  

   similar 
  in 
  general 
  character 
  to 
  that 
  which 
  we 
  have 
  been 
  seeing 
  ever 
  

   since 
  we 
  came 
  near 
  Klausen 
  " 
  (Appendix, 
  p. 
  106). 
  Between 
  two 
  and 
  

   three 
  miles 
  from 
  Lienz 
  we 
  came 
  to 
  a 
  number 
  of 
  outcrops 
  of 
  a 
  very 
  

   different 
  type 
  of 
  rock. 
  This 
  resembles 
  one 
  of 
  the 
  strong 
  but 
  rather 
  

   micaceous 
  schists, 
  or 
  fine 
  granular 
  gneisses 
  containing 
  much 
  black 
  

   mica, 
  that 
  are 
  not 
  rare 
  in 
  the 
  Alps. 
  It 
  is 
  the 
  " 
  mica-schist 
  " 
  of 
  Yon 
  

   Hauer 
  ; 
  his 
  " 
  gneiss," 
  of 
  which 
  only 
  a 
  comparatively 
  narrow 
  band 
  is 
  

   exposed, 
  recalled 
  to 
  me 
  the 
  granitoid 
  rock 
  of 
  the 
  Antholzerthal. 
  

   It 
  is 
  succeeded 
  by 
  more 
  " 
  mica-schist." 
  Near 
  St. 
  Johann 
  im 
  Wald 
  

   is 
  a 
  second 
  small 
  outcrop 
  of 
  " 
  gneiss." 
  Blocks 
  fallen 
  from 
  the 
  crags 
  

   above 
  indicated 
  two 
  types 
  of 
  rock, 
  one 
  a 
  fine-grained 
  gneiss, 
  the 
  

   other 
  a 
  coarse-grained 
  rock 
  with 
  crystals 
  of 
  tourmaline 
  and 
  large 
  

   flakes 
  of 
  mica. 
  Rain 
  prevented 
  us 
  from 
  giving 
  much 
  attention 
  to 
  

   this 
  outcrop 
  ; 
  but 
  the 
  general 
  aspect 
  of 
  the 
  crags 
  and 
  of 
  the 
  blocks 
  

   scattered 
  by 
  the 
  road 
  reminded 
  us 
  of 
  the 
  granitoid 
  rock 
  in 
  the 
  An- 
  

   tholzerthal. 
  Beyond 
  St. 
  Johann 
  the 
  " 
  mica-schist 
  " 
  recurs, 
  and 
  we 
  

   examined 
  it 
  more 
  than 
  once. 
  The 
  rock 
  is 
  often 
  very 
  distinctly 
  

   banded 
  with 
  alternating 
  white 
  (quartzose) 
  and 
  dark 
  (micaceous) 
  

   layers. 
  This 
  stratification-foliation 
  is 
  modified 
  by 
  a 
  cleavage-foli- 
  

   ation, 
  which 
  has 
  a 
  general 
  W.S.W. 
  strike, 
  and 
  dips 
  at 
  about 
  60° 
  on 
  

   the 
  southern 
  side. 
  Sometimes 
  the 
  two 
  structures 
  coincide, 
  but 
  

   often 
  the 
  latter 
  crosses 
  the 
  former 
  at 
  high 
  angles, 
  and 
  various 
  con- 
  

   tortions 
  are 
  produced. 
  In 
  short, 
  just 
  as 
  in 
  the 
  "Thonglimmerschiefer" 
  

   the 
  mineral 
  banding 
  behaves 
  as 
  the 
  " 
  stripe 
  " 
  in 
  a 
  slate 
  which 
  has 
  

   been 
  much 
  contorted 
  before 
  it 
  set 
  up 
  cleavage. 
  The 
  " 
  mica-schist 
  " 
  

   of 
  Von 
  Hauer 
  reminded 
  me 
  of 
  parts 
  of 
  the 
  Lepontine 
  group, 
  

   especially 
  such 
  varieties 
  as 
  we 
  find 
  south 
  of 
  the 
  crest 
  of 
  the 
  St. 
  Got- 
  

   hard, 
  or 
  about 
  the 
  Passo 
  del 
  Uomo, 
  and 
  on 
  the 
  ascent 
  from 
  Airolo 
  

   to 
  the 
  Val 
  Piora. 
  

  

  For 
  some 
  distance 
  below 
  Windisch-llatrei 
  the 
  valley 
  is 
  rather 
  

   open 
  and 
  comparatively 
  flat, 
  but 
  the 
  little 
  town 
  nestles 
  at 
  the 
  base 
  

   of 
  the 
  eastern 
  mountains. 
  The 
  neighbouring 
  rock 
  obviously 
  belongs 
  

   to 
  the 
  " 
  Thonglimmerschiefer 
  " 
  series. 
  On 
  the 
  hills 
  east 
  of 
  the 
  town 
  we 
  

   collected 
  in 
  situ 
  micaceous 
  varieties 
  of 
  this 
  rock, 
  the 
  chloritic 
  schists 
  

   associated 
  with 
  it 
  (presently 
  to 
  be 
  mentioned), 
  and 
  a 
  white 
  quartz- 
  

   schist. 
  The 
  slopes 
  also 
  were 
  strewn 
  with 
  fragments 
  of 
  silvery 
  

   quartz-mica-schist, 
  containing 
  a 
  few 
  red 
  garnets, 
  with 
  other 
  mica- 
  

  

  