﻿208 
  PROF. 
  J. 
  W. 
  JEDD 
  OX 
  THE 
  TEETIAEY 
  VOLCANOES 
  

  

  and 
  is 
  replaced 
  by 
  that 
  of 
  another. 
  "Where 
  both 
  are 
  of 
  the 
  same 
  

   variety 
  of 
  rock, 
  it 
  requires 
  close 
  inspection 
  to 
  make 
  out 
  the 
  difference 
  

   between 
  them 
  : 
  but 
  where 
  one 
  is 
  a 
  green, 
  dull, 
  earthy, 
  amorphous 
  

   amygdaloid, 
  and 
  the 
  other 
  is 
  a 
  compact, 
  black, 
  prismatic 
  basalt, 
  the 
  

   contrast 
  between 
  the 
  two 
  beds 
  can 
  be 
  recognized 
  from 
  a 
  distance. 
  

   Again, 
  along 
  the 
  west 
  coast 
  of 
  Rkye, 
  the 
  really 
  lenticular 
  character 
  

   of 
  the 
  beds 
  can 
  be 
  well 
  seen. 
  ?? 
  (T. 
  E. 
  S. 
  E. 
  1888, 
  pp. 
  SO. 
  SI.) 
  

  

  The 
  author 
  goes 
  on 
  to 
  show 
  that 
  the 
  detailed 
  study 
  of 
  the 
  lavas 
  of 
  

   Antrim, 
  where 
  the 
  Geological 
  Survey 
  has 
  been 
  completed, 
  strongly 
  

   supports 
  the 
  same 
  views. 
  

  

  In 
  reply 
  to 
  those 
  who 
  believe 
  that 
  such 
  basaltic 
  plateaux 
  as 
  those 
  

   of 
  Antrim, 
  consisting 
  of 
  successive 
  lava-sheets, 
  lying 
  almost 
  hori- 
  

   zontally, 
  and 
  piled 
  upon 
  one 
  another 
  to 
  a 
  very 
  great 
  thickness, 
  

   could 
  not 
  possibly 
  have 
  been 
  poured 
  out 
  from 
  volcanoes. 
  I 
  cannot 
  

   do 
  better 
  than 
  point 
  to 
  the 
  example 
  of 
  the 
  Sandwich 
  Islands. 
  And 
  

   very 
  opportunely 
  we 
  have 
  just 
  at 
  the 
  present 
  time 
  new 
  and 
  im- 
  

   portant 
  light 
  thrown 
  upon 
  that 
  interesting 
  district 
  by 
  the 
  valuable 
  

   studies 
  of 
  Captain 
  Dutton 
  * 
  and 
  the 
  still 
  more 
  striking 
  observations 
  

   recently 
  made 
  by 
  the 
  veteran 
  Professor 
  J. 
  D. 
  Dana 
  t. 
  Geologists 
  

   all 
  over 
  the 
  world 
  may 
  well 
  hesitate 
  as 
  to 
  which 
  calls 
  for 
  the 
  

   greater 
  admiration 
  — 
  the 
  vigour 
  and 
  enthusiasm 
  which 
  prompted 
  our 
  

   esteemed 
  Foreign 
  AEember 
  to 
  undertake 
  a 
  journey 
  often 
  thousand 
  

   miles 
  in 
  order 
  to 
  clear 
  up 
  difficulties 
  left 
  in 
  his 
  original 
  studies 
  of 
  

   the 
  district 
  in 
  1840 
  — 
  or 
  the 
  new 
  and 
  valuable 
  results 
  obtained 
  by 
  the 
  

   investigations 
  of 
  one 
  who, 
  after 
  nearly 
  half 
  a 
  century 
  of 
  thought 
  and 
  

   inquiry, 
  has 
  returned 
  to 
  the 
  field 
  of 
  his 
  early 
  observations. 
  

  

  The 
  island 
  of 
  Hawaii, 
  taking 
  only 
  that 
  portion 
  of 
  the 
  mass 
  which 
  

   is 
  at 
  present 
  above 
  the 
  sea-level, 
  has 
  an 
  area 
  almost 
  identical 
  with 
  

   that 
  of 
  the 
  basaltic 
  plateau 
  of 
  Antrim, 
  and 
  the 
  rocks 
  composing 
  the 
  

   island, 
  though 
  undenuded, 
  form 
  a 
  great 
  mass, 
  the 
  slopes 
  of 
  which 
  

   seldom, 
  if 
  ever, 
  exceed 
  a 
  few 
  degrees. 
  The 
  individual 
  lava-streams, 
  

   like 
  those 
  of 
  Antrim, 
  are 
  of 
  the 
  most 
  varied 
  bulk 
  and, 
  like 
  them, 
  

   also 
  lie 
  almost 
  horizontally 
  : 
  in 
  many 
  parts 
  only 
  insignificant 
  beds 
  of 
  

   tuff 
  or 
  ash 
  can 
  be 
  detected 
  between 
  the 
  different 
  lava-sheets. 
  Yet 
  

   there 
  cannot 
  be 
  the 
  smallest 
  doubt 
  that 
  this 
  plateau 
  of 
  basalt 
  has 
  

   been 
  formed 
  by 
  ejection 
  from 
  the 
  three 
  great 
  volcanoes 
  — 
  Atauna 
  

   Loa, 
  ATauna 
  Kea. 
  and 
  Hualalai. 
  Either 
  from 
  the 
  summit-craters 
  

   of 
  those 
  volcanoes 
  or 
  from 
  the 
  numerous 
  parasitical 
  vents 
  that 
  have 
  

   been 
  opened 
  upon 
  their 
  flanks 
  have 
  the 
  successive 
  lava-cnrrente, 
  — 
  

   sometimes 
  small 
  and 
  insignificant, 
  at 
  other 
  times 
  forming 
  vast 
  floods 
  

   of 
  molten 
  rock 
  — 
  been 
  poured 
  out. 
  

  

  The 
  examination 
  of 
  the 
  Antrim-plateau, 
  which 
  has 
  been 
  carried 
  

   on 
  during 
  the 
  last 
  twenty-five 
  years 
  by 
  different 
  officers 
  of 
  the 
  

   Geological 
  Survey, 
  has 
  shown 
  that 
  too 
  much 
  importance 
  must 
  not 
  

   be 
  attached 
  to 
  the. 
  at 
  present, 
  almost 
  horizontal 
  position 
  of 
  the 
  

   several 
  lava-sheets 
  of 
  which 
  it 
  is 
  composed, 
  or 
  to 
  the 
  inclinations 
  

   which 
  they 
  can 
  now 
  be 
  shown 
  to 
  exhibit. 
  The 
  author 
  of 
  the 
  recent 
  

   memoir 
  states 
  that 
  " 
  the 
  varying 
  dip 
  of 
  the 
  beds 
  must 
  be 
  attributed 
  

  

  * 
  Fourth 
  Kep. 
  U. 
  S. 
  Geol. 
  Surv. 
  pp. 
  81-219. 
  

   t 
  Ann. 
  Journ. 
  Sci. 
  3rd 
  ser. 
  vols, 
  xxxiii.-xxxvii. 
  

  

  