﻿76 
  PKOF. 
  T. 
  G. 
  BONNET 
  ON 
  TWO 
  TRAVEKSES 
  OE 
  THE 
  

  

  highest, 
  terminates 
  a 
  shorter 
  spur 
  to 
  the 
  south. 
  Several 
  of 
  the 
  peaks- 
  

   rise 
  above 
  12,000 
  feet, 
  the 
  highest, 
  Les 
  Ecrins, 
  attaining 
  13,462, 
  

   while 
  the 
  passes 
  between 
  them 
  generally 
  range 
  from 
  10,000 
  to 
  over 
  

   11,000 
  in 
  elevation. 
  Opposite 
  to 
  La 
  Grave 
  the 
  northern 
  face 
  of 
  the 
  

   massif 
  rises 
  with 
  unusual 
  steepness. 
  Prom 
  the 
  door 
  of 
  the 
  hotel 
  we 
  

   look 
  up 
  to 
  the 
  jagged 
  crtie 
  of 
  the 
  Meije, 
  the 
  highest 
  point 
  of 
  which 
  

   is 
  13,081 
  feet 
  above 
  the 
  sea. 
  According 
  to 
  the 
  Prenchmap, 
  the 
  dis- 
  

   tance 
  between 
  the 
  summit 
  of 
  this 
  peak 
  and 
  the 
  bed 
  of 
  the 
  Romanche, 
  

   which 
  is 
  considerably, 
  perhaps 
  200 
  feet, 
  below 
  La 
  Grave, 
  is 
  about 
  

   4500 
  metres, 
  and 
  the 
  difference 
  of 
  elevation 
  is 
  hardly 
  less 
  than 
  

   2500 
  metres, 
  giving 
  an 
  average 
  rise 
  of 
  5 
  in 
  9, 
  or 
  more 
  than 
  1 
  

   in 
  2. 
  The 
  impression 
  produced 
  on 
  the 
  mind 
  is 
  that 
  a 
  great 
  dome- 
  

   like 
  mass 
  of 
  crystalline 
  rock 
  has 
  been 
  pushed 
  through 
  the 
  sedi- 
  

   mentaries, 
  thrusting 
  them 
  back, 
  crumpling 
  them 
  about 
  its 
  edges, 
  

   infolding 
  portions 
  in 
  its 
  undulations, 
  or 
  lifting 
  them 
  upon 
  its 
  arches. 
  

   The 
  great 
  folds 
  in 
  the 
  Jurassic 
  strata 
  at 
  the 
  base 
  of 
  the 
  Meije 
  

   opposite 
  La 
  Grave 
  — 
  which 
  may 
  be 
  seen 
  in 
  every 
  photograph 
  — 
  are 
  

   well 
  known 
  to 
  many. 
  This 
  mass 
  of 
  slate 
  can 
  still 
  be 
  traced 
  some 
  

   distance 
  up 
  the 
  glen, 
  which 
  descends 
  from 
  the 
  Glacier 
  de 
  la 
  Breche 
  de 
  

   la 
  Meije 
  ; 
  and 
  I 
  detected 
  last 
  year 
  two 
  small 
  outliers 
  at 
  the 
  foot 
  of 
  the 
  

   glacier, 
  one 
  on 
  either 
  side, 
  at 
  a 
  height 
  probably 
  of 
  about 
  8000 
  feet 
  

   above 
  the 
  sea. 
  Perhaps 
  even 
  more 
  remarkable 
  is 
  another 
  outlier 
  

   further 
  to 
  the 
  west, 
  where 
  a 
  long 
  spur 
  running 
  in 
  that 
  direction 
  from 
  

   the 
  Bateau 
  (the 
  mountain 
  west 
  of 
  the 
  Breche), 
  falls 
  down 
  rather 
  

   abruptly 
  to 
  a 
  huge 
  glacier-covered 
  plateau. 
  Here 
  we 
  find 
  a 
  little 
  out- 
  

   lier 
  of 
  black 
  Jurassic 
  slate, 
  at 
  the 
  Col 
  de 
  la 
  Lauze, 
  11,500 
  feet 
  above 
  

   the 
  sea*. 
  I 
  do 
  not 
  know 
  the 
  exact 
  height 
  of 
  the 
  base 
  of 
  the 
  Jurassic 
  

   series 
  across 
  the 
  Combe 
  de 
  Malaval 
  due 
  north 
  of 
  this 
  point, 
  but 
  it 
  

   can 
  hardly 
  exceed 
  6000 
  feet, 
  so 
  that 
  we 
  have 
  an 
  uplift 
  of 
  about 
  

   5500 
  ft., 
  or 
  not 
  less 
  than 
  a 
  mile 
  vertical 
  in 
  about 
  3 
  miles 
  f 
  . 
  

  

  At 
  La 
  Grave 
  we 
  spent 
  3 
  or 
  4 
  days 
  in 
  order 
  to 
  acquire 
  a 
  general 
  

   idea 
  of 
  the 
  rocks 
  forming 
  the 
  northern 
  face 
  of 
  the 
  crystalline 
  massif 
  

   by 
  examining 
  both 
  the 
  glen 
  descending 
  from 
  the 
  Breche 
  de 
  la 
  Meije 
  

   and 
  the 
  larger 
  valley, 
  the 
  main 
  stream 
  of 
  the 
  Eomanche, 
  which 
  

   sweeps 
  round 
  the 
  eastern 
  flank 
  of 
  the 
  Meije, 
  and 
  thus 
  drains 
  both 
  the 
  

   range 
  for 
  some 
  distance 
  south 
  of 
  that 
  mountain 
  and 
  the 
  north 
  face 
  

   of 
  the 
  Crete 
  du 
  Glacier 
  Blanc. 
  Examination 
  of 
  rock 
  in 
  situ 
  and 
  of 
  

   the 
  materials 
  brought 
  down 
  by 
  glaciers 
  and 
  torrents, 
  recollection 
  of 
  

   my 
  earlier 
  scrambles, 
  and 
  study 
  of 
  Mr. 
  Coolidge's 
  collections 
  from 
  

   the 
  higher 
  peaks 
  and 
  passes, 
  enable 
  me 
  to 
  indicate 
  with, 
  I 
  believe, 
  

   tolerable 
  correctness 
  the 
  chief 
  varieties 
  of 
  rock 
  which 
  occur 
  in 
  this 
  

   wild 
  region. 
  The 
  rocks 
  from 
  the 
  Bateau 
  eastwards 
  are 
  mainly 
  

   divisible 
  into 
  two 
  pretty 
  distinct 
  groups, 
  one 
  consisting 
  of 
  rather 
  

   granitoid 
  gneisses, 
  the 
  other 
  more 
  or 
  less 
  gneissoid 
  granites. 
  In 
  

  

  * 
  There 
  is 
  another 
  on 
  the 
  glacier 
  lower 
  down, 
  perhaps 
  10,000 
  feet 
  above 
  

   the 
  sea. 
  

  

  t 
  These 
  masses 
  may 
  be 
  carried 
  up 
  by 
  upthrust 
  faults 
  ; 
  but 
  I 
  have 
  seen 
  no 
  

   evidence 
  of 
  this, 
  and 
  it 
  seems 
  to 
  me 
  more 
  like 
  a 
  bending 
  of 
  the 
  underlying 
  

   crystalline 
  and 
  the 
  Jurassic 
  in 
  common, 
  which 
  has 
  produced 
  local 
  crumpling 
  

   of 
  the 
  latter. 
  

  

  