﻿16 
  PROF. 
  T. 
  G. 
  BONNET 
  ON 
  THE 
  SECTIONS 
  NEAR 
  [Feb. 
  1 
  89 
  

  

  /'» 
  

  

  2. 
  Additional 
  Note 
  on 
  the 
  Sections 
  near 
  the 
  Summit 
  of 
  the 
  Ffrka. 
  

   Pass 
  (Switzerland). 
  By 
  T. 
  G. 
  Bonnet, 
  D.Sc, 
  LL.D., 
  F.P.S., 
  

   Y.P.G.S., 
  Professor 
  of 
  Geology 
  in 
  University 
  College, 
  London, 
  

   and 
  Fellow 
  of 
  St. 
  John's 
  College, 
  Cambridge. 
  (Eead 
  November 
  

   4th, 
  1896.) 
  

  

  In 
  1894 
  I 
  gave 
  an 
  account 
  1 
  of 
  certain 
  sections 
  in 
  the 
  valley 
  of 
  the 
  

   Beuss 
  (Switzerland) 
  where 
  a 
  somewhat 
  schistose 
  white 
  marble 
  is 
  

   associated 
  with 
  phyllites 
  and 
  limestones 
  of 
  Jurassic 
  age. 
  But 
  of 
  that 
  

   on 
  the 
  Furka 
  Pass, 
  as 
  then 
  stated, 
  the 
  description 
  was 
  incomplete, 
  as 
  

   I 
  had 
  been 
  compelled, 
  owing 
  to 
  unfavourable 
  weather, 
  to 
  be 
  content 
  

   with 
  a 
  hurried 
  glance 
  at 
  that 
  part 
  of 
  the 
  infold 
  which 
  is 
  on 
  the 
  

   western 
  side 
  of 
  the 
  summit. 
  Here 
  the 
  road, 
  curving 
  round 
  from 
  a 
  

   W.S.W. 
  to 
  "W.N.W. 
  direction, 
  cuts 
  across 
  the 
  apparent 
  strike 
  of 
  

   the 
  sedimentary 
  rocks, 
  and 
  then 
  quits 
  them 
  to 
  run 
  over 
  the 
  gneiss. 
  

   It 
  was 
  the 
  western 
  end 
  of 
  the 
  triangle 
  thus 
  formed, 
  a 
  piece 
  

   measuring 
  perhaps 
  400 
  yards 
  in 
  length 
  by 
  250 
  at 
  the 
  widest 
  part, 
  

   which 
  I 
  had 
  been 
  unable 
  to 
  examine. 
  But 
  in 
  the 
  summer 
  of 
  1895 
  

   I 
  walked 
  up 
  to 
  the 
  top 
  of 
  the 
  pass 
  from 
  the 
  valley 
  of 
  the 
  Phone, 
  in 
  

   company 
  with 
  my 
  friend 
  the 
  Rev. 
  E. 
  Hill, 
  whose 
  kind 
  help 
  I 
  gladly 
  

   acknowledge, 
  and 
  completed 
  the 
  examination 
  of 
  the 
  western 
  side, 
  

   besides 
  going 
  over 
  parts 
  of 
  the 
  area 
  which 
  I 
  had 
  visited 
  on 
  the 
  

   former 
  occasion. 
  A 
  few 
  additional 
  facts 
  were 
  obtained, 
  which 
  may 
  

   be 
  worth 
  bringing 
  to 
  the 
  notice 
  of 
  the 
  Society, 
  for, 
  although 
  they 
  are 
  

   not 
  conclusive 
  as 
  to 
  the 
  relation 
  of 
  the 
  marble 
  to 
  the 
  Jurassic 
  rock, 
  

   they 
  throw, 
  I 
  think, 
  some 
  light 
  upon 
  the 
  question. 
  

  

  On 
  the 
  western 
  side 
  of 
  the 
  pass, 
  to 
  speak 
  first 
  of 
  the 
  part 
  left 
  

   unexamined 
  on 
  the 
  previous 
  occasion, 
  the 
  live 
  rock 
  in 
  many 
  places 
  

   is 
  completely 
  hidden 
  by 
  debris 
  and 
  turf. 
  "We 
  have 
  to 
  make 
  the 
  best 
  

   of 
  various 
  outcrops, 
  which 
  become 
  more 
  isolated 
  as 
  we 
  go 
  west- 
  

   ward. 
  The 
  following 
  account, 
  however, 
  I 
  trust, 
  is 
  fairly 
  correct. 
  

   The 
  great 
  mass 
  of 
  slabby 
  marble, 
  2 
  mentioned 
  in 
  my 
  former 
  paper 
  as 
  

   crossing 
  the 
  pass 
  at 
  the 
  back 
  of 
  the 
  ' 
  dependance 
  ' 
  of 
  the 
  Furka 
  Inn 
  

   and 
  forming 
  a 
  crag 
  above 
  the 
  road, 
  appears 
  to 
  descend 
  gradually 
  

   towards 
  and 
  run 
  beneath 
  the 
  latter, 
  and 
  is 
  lost 
  under 
  turf 
  and 
  talus 
  

   on 
  the 
  steep 
  slope 
  below. 
  It 
  is 
  overlain 
  3 
  by 
  a 
  greyish 
  subcrystal- 
  

   line 
  limestone, 
  also 
  rather 
  slabby, 
  with 
  darker, 
  more 
  argillaceous 
  

   bands, 
  which 
  do 
  not 
  look 
  at 
  all 
  crystalline. 
  This 
  rock 
  in 
  general 
  

   aspect 
  corresponds 
  with 
  No. 
  3 
  of 
  the 
  section 
  on 
  p. 
  295 
  (op. 
  cit.), 
  and 
  

   reveals 
  traces 
  of 
  organisms 
  under 
  the 
  microscope. 
  Higher 
  up 
  comes 
  

   a 
  small 
  outcrop 
  of 
  a 
  rock 
  which 
  presents 
  more 
  resemblance 
  to 
  a 
  

   very 
  crushed 
  condition 
  of 
  the 
  marble 
  than 
  to 
  one 
  of 
  the 
  ordinary 
  

  

  1 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  1. 
  (1894) 
  p. 
  285. 
  

  

  2 
  No. 
  2 
  in 
  the 
  description 
  given 
  on 
  p. 
  294 
  (op. 
  cit.). 
  

  

  3 
  I 
  speak 
  throughout 
  this 
  paper 
  of 
  the 
  apparent 
  succession 
  of 
  the 
  outcrops 
  

   on 
  the 
  mountain-slopes. 
  

  

  