﻿CRYSTALLINE 
  ROCKS 
  OF 
  THE 
  ALPS. 
  

  

  85 
  

  

  interval), 
  apparently 
  in 
  due 
  succession, 
  a 
  fissile 
  greenish 
  or 
  lead- 
  

   coloured 
  mica-schist, 
  its 
  dominant 
  structure 
  being 
  a 
  cleavage-foli- 
  

   ation 
  which 
  strikes 
  roughly 
  S. 
  of 
  W. 
  and 
  dips 
  at 
  about 
  75° 
  on 
  the 
  

   eastern 
  side. 
  A 
  quarry 
  on 
  the 
  hill-side 
  about 
  80 
  feet 
  above 
  this 
  

   gives 
  a 
  more 
  definite 
  strike 
  W.N.W. 
  to 
  E.S.E., 
  with 
  a 
  high 
  dip 
  

   on 
  the 
  southern 
  side. 
  Here 
  the 
  rock 
  distinctly 
  exhibits 
  a 
  stratifi- 
  

   cation-foliation 
  and 
  a 
  (subsequent) 
  cleavage-foliation, 
  the 
  former 
  

   being 
  indicated 
  by 
  quartzose 
  layers 
  from 
  about 
  -1" 
  to 
  *2" 
  thick, 
  

   separated 
  by 
  thin 
  but 
  well-defined 
  layers 
  of 
  mica. 
  The 
  two 
  

   structures 
  commonly 
  coincide 
  ; 
  but 
  instances 
  may 
  be 
  found 
  where 
  the 
  

   mineral 
  bands 
  are 
  bent, 
  folded, 
  and 
  zigzag 
  across 
  the 
  direction 
  of 
  

   the 
  cleavage-foliation, 
  as 
  the 
  "stripe" 
  often 
  crosses 
  the 
  cleavage 
  in 
  a 
  

   banded 
  slate. 
  Where 
  the 
  two 
  coincide, 
  the 
  layers 
  of 
  mica 
  are 
  crushed 
  

   and 
  burnished, 
  probably 
  by 
  a 
  slight 
  shearing, 
  while 
  in 
  the 
  crossing 
  

   they 
  are 
  puckered 
  and 
  rather 
  crushed, 
  but 
  the 
  bands 
  of 
  quartz 
  are 
  

   only 
  slightly 
  affected 
  (fig. 
  5). 
  

  

  Fig. 
  5. 
  — 
  Quartz^mica-schist 
  from 
  Quarry 
  near 
  Brunecken. 
  

  

  The 
  lines 
  indicate 
  the 
  thin 
  bands 
  of 
  mica 
  ; 
  the 
  arrows 
  point 
  to 
  the 
  " 
  sheen 
  

   surfaces 
  " 
  at 
  right 
  angles 
  to 
  the 
  visible 
  face 
  of 
  the 
  block. 
  Length 
  about 
  1 
  foot. 
  

  

  As 
  the 
  section 
  which 
  we 
  proposed 
  to 
  make 
  across 
  the 
  Central 
  

   Chain 
  promised 
  to 
  exhibit 
  but 
  little 
  of 
  Yon 
  Hauer's 
  gneiss, 
  we 
  made 
  

   a 
  short 
  excursion 
  from 
  Brunecken 
  into 
  the 
  Antholzerthal. 
  Here, 
  

   above 
  Oberrasen, 
  we 
  found 
  excellent 
  exposures 
  of 
  the 
  former 
  rock. 
  

   It 
  is 
  a 
  grey 
  gneissoid 
  granite, 
  rather 
  coarse 
  and 
  sometimes 
  porphy- 
  

   ritic 
  in 
  texture, 
  slightly 
  foliated, 
  but 
  without 
  mineral 
  banding. 
  In 
  

   its 
  jointing 
  and 
  mode 
  of 
  weathering 
  it 
  much 
  resembles 
  a 
  true 
  

   granite, 
  and 
  somewhat 
  reminded 
  me, 
  in 
  its 
  general 
  aspect, 
  of 
  the 
  

   granite 
  on 
  the 
  Lukmanier 
  Pass. 
  South 
  of 
  this, 
  perhaps 
  mapped 
  as 
  

   mica-schist, 
  is 
  a 
  gneissic 
  rock, 
  much 
  more 
  fissile, 
  on 
  the 
  original 
  

   character 
  of 
  which, 
  owing 
  to 
  the 
  great 
  crushing, 
  it 
  is 
  difficult 
  to 
  

   decide. 
  The 
  cleavage-foliation 
  struck 
  a 
  little 
  S. 
  of 
  S.W. 
  and 
  was 
  

   nearly 
  vertical, 
  corresponding 
  with 
  the 
  foliation 
  in 
  the 
  granitoid 
  

   rock. 
  

  

  Between 
  Bruuecken 
  and 
  Lienz, 
  the 
  railway 
  to 
  beyond 
  Olang 
  and 
  

   below 
  Innichen 
  passes 
  or 
  cuts, 
  not 
  unfrequently, 
  outcrops 
  of 
  the 
  

   "ThonglimmerscJiiefer" 
  which 
  is 
  generally 
  of 
  the 
  normal 
  lead-coloured 
  

   variety. 
  On 
  this 
  rock 
  evidently 
  rest 
  the 
  great 
  masses 
  of 
  dolomite 
  

  

  