﻿214 
  PROF. 
  J. 
  W. 
  JFDD 
  OX 
  THE 
  TEETIAEY 
  VOLCANOES 
  

  

  cones, 
  so 
  exactly 
  reproduces 
  the 
  features 
  illustrated 
  by 
  Mr. 
  Scrope 
  

   in 
  his 
  well-known 
  panoramic 
  views 
  of 
  the 
  Auvergne, 
  that 
  it 
  seems 
  

   difficult 
  to 
  understand 
  how 
  any 
  geologist 
  could 
  maintain 
  totally 
  

   distinct 
  modes 
  of 
  origin 
  for 
  these 
  features 
  in 
  the 
  two 
  cases. 
  

  

  Captain 
  Dutton's 
  remarks 
  on 
  the 
  High 
  Plateaux 
  of 
  Utah 
  and 
  the 
  

   lava-fields 
  of 
  New 
  Mexico 
  are 
  also 
  quoted 
  as 
  giving 
  still 
  further 
  

   support 
  to 
  the 
  theory 
  of 
  "fissure-eruptions." 
  

  

  A 
  reference 
  to 
  these 
  writings 
  of 
  Captain 
  Dutton, 
  however, 
  shows 
  

   that 
  cones 
  and 
  craters 
  are 
  by 
  no 
  means 
  absent 
  in 
  the 
  districts 
  

   referred 
  to 
  ; 
  they 
  are, 
  indeed, 
  said 
  to 
  be 
  very 
  numerous 
  in 
  some 
  parts 
  

   of 
  the 
  areas, 
  though 
  usually 
  of 
  small 
  size. 
  Moreover 
  the 
  lava-fields 
  

   are 
  stated 
  in 
  some 
  cases 
  to 
  have 
  suffered 
  so 
  greatly 
  from 
  denudation 
  

   that 
  it 
  would 
  be 
  a 
  hopeless 
  task 
  to 
  look 
  for 
  cinder-cones 
  upon 
  them. 
  

  

  ISut 
  there 
  is 
  one 
  very 
  important 
  circumstance 
  which 
  seems 
  to 
  

   have 
  been 
  unfortunately 
  overlooked 
  by 
  my 
  critic. 
  Captain 
  Dutton, 
  

   after 
  studying 
  the 
  lava-fields 
  of 
  the 
  Western 
  Territories, 
  and 
  showing 
  

   some 
  disposition 
  to 
  refer 
  them 
  to 
  "fissure 
  eruptions," 
  paid 
  a 
  visit 
  

   to 
  the 
  Sandwich 
  Islands, 
  and 
  there 
  — 
  amid 
  the 
  abundant 
  proofs 
  

   afforded 
  to 
  him 
  of 
  the 
  fact 
  that 
  from 
  the 
  summit 
  and 
  sides 
  of 
  true 
  

   volcanoes 
  highly 
  liquid 
  basaltic 
  lavas 
  are 
  often 
  poured 
  out, 
  with 
  

   but 
  a 
  very 
  slight 
  accompaniment 
  of 
  explosive 
  action 
  — 
  he 
  very 
  can- 
  

   didly 
  confessed 
  that 
  he 
  felt 
  he 
  might 
  have 
  been 
  in 
  error 
  in 
  invoking 
  

   the 
  aid 
  of 
  the 
  "fissure-eruption" 
  hypothesis 
  to 
  account 
  for 
  the 
  

   phenomena 
  witnessed 
  by 
  him 
  in 
  his 
  own 
  country. 
  Captain 
  Dutton's 
  

   remarks 
  are 
  so 
  much 
  to 
  the 
  point 
  that 
  I 
  cannot 
  do 
  better 
  than 
  

   quote 
  them. 
  

  

  Referring 
  to 
  the 
  lava 
  poured 
  out 
  from 
  Mauna 
  Loa 
  in 
  1855, 
  

   Captain 
  Dutton 
  remarks 
  : 
  — 
  ■ 
  

  

  " 
  As 
  I 
  looked 
  over 
  this 
  expanse 
  of 
  lava, 
  I 
  was 
  forcibly 
  reminded 
  

   of 
  some 
  of 
  the 
  great 
  volcanic 
  fields 
  of 
  the 
  western 
  portion 
  of 
  the 
  

   United 
  States, 
  where 
  the 
  eruptions 
  are 
  of 
  such 
  colossal 
  proportions 
  

   that 
  they 
  have 
  received 
  the 
  name 
  of 
  massive 
  eruptions. 
  Richthcfen, 
  

   after 
  studying 
  many 
  of 
  these 
  lava-fields 
  in 
  California 
  and 
  Nevada, 
  

   was 
  led 
  to 
  the 
  conclusion 
  that 
  they 
  had 
  burst 
  forth 
  from 
  great 
  

   fissures, 
  inundating 
  large 
  areas 
  of 
  country 
  with 
  fiery 
  seas 
  of 
  basalt. 
  

   He 
  was 
  led 
  to 
  contrast 
  the 
  immense 
  volume 
  of 
  these 
  rocks 
  with 
  the 
  

   comparatively 
  insignificant 
  streams 
  which 
  have 
  emanated 
  from 
  

   Vesuvius, 
  ./Etna 
  aud 
  other 
  modern 
  volcanoes, 
  and 
  concluded 
  that 
  

   the 
  incomparably 
  grander 
  overflows 
  of 
  Western 
  America 
  must 
  

   have 
  occurred 
  under 
  circumstances 
  differing 
  widely 
  from 
  those 
  of 
  

   ordinary 
  volcanic 
  eruptions. 
  Although 
  the 
  volcanic 
  rocks 
  of 
  Western 
  

   America 
  may 
  be 
  considered 
  as 
  very 
  well 
  exposed, 
  as 
  compared 
  with 
  

   rocks 
  of 
  equal 
  antiquity 
  in 
  other 
  portions 
  of 
  the 
  world, 
  they 
  would 
  

   be 
  regarded 
  as 
  relatively 
  obscure 
  by 
  any 
  one 
  who 
  has 
  had 
  an 
  

   opportunity 
  to 
  inspect 
  carefully 
  the 
  recent 
  lavas 
  of 
  Mauna 
  Loa. 
  I 
  

   am 
  by 
  no 
  means 
  certain 
  that 
  Eichthofen's 
  conclusions 
  are 
  wrong. 
  

   But 
  here 
  is 
  a 
  lava-flow, 
  the 
  dimensions 
  of 
  which 
  fully 
  rival 
  some 
  of 
  

   the 
  grand 
  pliocene 
  outbreaks 
  of 
  the 
  west, 
  which 
  demonstrably 
  differs 
  

   in 
  no 
  material 
  respect, 
  excepting 
  in 
  grandeur, 
  from 
  the 
  much 
  

   smaller 
  eruptions 
  of 
  normal 
  volcanoes 
  " 
  *. 
  

  

  * 
  Fourth 
  Eep. 
  U. 
  S. 
  Geol. 
  Surr. 
  p. 
  156. 
  

  

  