﻿OF 
  THE 
  VALLEY 
  OF 
  THE 
  RHINE. 
  95 
  

  

  the 
  author's 
  view 
  as 
  correct 
  ; 
  but 
  the 
  question 
  still 
  remained 
  as 
  to 
  

   how 
  far 
  the 
  gorge 
  was 
  due 
  to 
  gradual 
  erosion 
  and 
  how 
  far 
  to 
  some 
  

   subterranean 
  action. 
  

  

  Prof. 
  Ramsay, 
  in 
  reply 
  to 
  Mr. 
  Hugh 
  Miller, 
  stated 
  that 
  the 
  de- 
  

   tritus 
  brought 
  from 
  the 
  north 
  was 
  found 
  in 
  Switzerland, 
  and 
  that 
  

   Prof. 
  Sandberger 
  considered 
  that 
  at 
  the 
  time 
  of 
  its 
  transport 
  the 
  

   Jura 
  was 
  not 
  in 
  existence. 
  He 
  had 
  conversed 
  with 
  all 
  the 
  principal 
  

   Swiss 
  geologists 
  ; 
  and 
  it 
  was 
  from 
  thern 
  he 
  learnt 
  that, 
  along 
  what 
  

   is 
  now 
  a 
  part 
  of 
  the 
  valley 
  of 
  the 
  Rhine, 
  a 
  river 
  flowing 
  south- 
  

   wards, 
  during 
  episodes 
  in 
  the 
  Miocene 
  period, 
  carried 
  pebbles 
  from 
  

   the 
  north 
  along 
  its 
  course. 
  This 
  river 
  must 
  have 
  dated 
  back 
  even 
  

   to 
  Eocene 
  times. 
  In 
  reply 
  to 
  Prof. 
  Hughes, 
  he 
  stated 
  that 
  the 
  

   attribution 
  of 
  the 
  volcanic 
  outflows 
  to 
  Miocene 
  times 
  was 
  somewhat 
  

   problematical, 
  and 
  that 
  there 
  was 
  some 
  probability 
  of 
  their 
  belonging 
  

   to 
  a 
  more 
  recent 
  period. 
  Neither 
  did 
  they 
  affect 
  the 
  district 
  mainly 
  

   under 
  consideration. 
  There 
  was 
  no 
  great 
  succession 
  of 
  terraces, 
  but 
  

   one 
  main 
  terrace 
  of 
  fluviatile 
  origin, 
  of 
  which 
  extensive 
  traces 
  re- 
  

   mained. 
  Similar 
  terraces 
  occurred 
  on 
  the 
  Moselle. 
  In 
  reply 
  to 
  the 
  

   Duke 
  of 
  Argyll, 
  he 
  stated 
  that 
  he 
  did 
  not 
  think 
  that 
  volcanic 
  action 
  

   had 
  any 
  thing 
  to 
  do 
  with 
  the 
  formation 
  of 
  the 
  gorge. 
  The 
  Miocene 
  

   strata 
  lay 
  in 
  an 
  approximately 
  horizontal 
  direction, 
  and 
  were 
  not 
  

   tilted 
  in 
  such 
  a 
  manner 
  as 
  to 
  suggest 
  that 
  their 
  absence 
  in 
  the 
  basin 
  

   was 
  due 
  to 
  any 
  disturbance 
  of 
  the 
  strata. 
  They 
  must, 
  in 
  his 
  view, 
  

   have 
  been 
  of 
  necessity 
  scooped 
  away 
  by 
  the 
  action 
  of 
  flowing 
  water. 
  

  

  til 
  

  

  