﻿482 
  MESSES. 
  E. 
  T. 
  NEWTON 
  ATS 
  T 
  D 
  J. 
  J. 
  H. 
  TEALL 
  ON 
  [Dec. 
  I 
  89 
  7, 
  

  

  fossils, 
  which 
  has 
  now 
  been 
  received, 
  throws 
  additional 
  light 
  on 
  the 
  

   geological 
  structure 
  of 
  the 
  Franz 
  Josef 
  Land 
  archipelago. 
  Although 
  

   the 
  cliffs 
  are 
  so 
  largely 
  hidden 
  by 
  talus-heaps 
  and 
  snow, 
  that 
  

   exposures 
  of 
  rock 
  are 
  few 
  and 
  far 
  between, 
  yet 
  the 
  specimens 
  

   now 
  collected 
  by 
  Mr. 
  Jackson's 
  party 
  have 
  all 
  been 
  so 
  carefully 
  

   labelled 
  and 
  localized 
  that 
  it 
  has 
  been 
  possible 
  to 
  piece 
  them 
  

   together, 
  so 
  as 
  to 
  present 
  what 
  we 
  believe 
  to 
  be 
  a 
  correct 
  idea 
  of 
  

   the 
  geology 
  of 
  some 
  of 
  the 
  southern 
  parts 
  of 
  Franz 
  Josef 
  Land. 
  

   We 
  have 
  received 
  much 
  help 
  from 
  Mr. 
  H. 
  Fisher, 
  the 
  botanist 
  of 
  

   the 
  expedition, 
  who 
  is 
  now 
  in 
  England 
  : 
  his 
  admirable 
  coloured 
  

   sketches 
  and 
  verbal 
  descriptions 
  doing 
  much 
  to 
  aid 
  us 
  in 
  realizing 
  

   the 
  actual 
  conditions 
  under 
  which 
  the 
  specimens 
  were 
  found. 
  

   Moreover, 
  Mr. 
  Fisher's 
  patience 
  in 
  answering 
  our 
  innumerable 
  and 
  

   perplexing 
  queries 
  has 
  helped 
  us 
  out 
  of 
  many 
  difficulties, 
  and 
  we 
  

   take 
  this 
  opportunity 
  of 
  tendering 
  him 
  our 
  warmest 
  thanks. 
  We 
  

   are 
  also 
  under 
  obligation 
  to 
  Dr. 
  G. 
  J. 
  Hinde 
  for 
  many 
  hints, 
  but 
  

   especially 
  for 
  his 
  Note 
  on 
  the 
  radiolarian 
  chert 
  from 
  the 
  iceberg. 
  

   We 
  have 
  moreover 
  received 
  help 
  and 
  many 
  kind 
  suggestions 
  from 
  

   our 
  colleagues, 
  Mr. 
  Clement 
  Beid, 
  Mr. 
  G. 
  Sharman, 
  and 
  Mr. 
  W. 
  W. 
  

   Watts, 
  and 
  we 
  desire 
  to 
  thank 
  all 
  these 
  friends, 
  and 
  to 
  acknowledge 
  

   our 
  indebtedness 
  to 
  them. 
  

  

  III. 
  The 
  Basalts 
  of 
  Franz 
  Josee 
  Land. 
  

  

  The 
  basaltic 
  rocks 
  which 
  form 
  so 
  important 
  a 
  feature 
  in 
  the 
  

   geology 
  of 
  Franz 
  Josef 
  Land 
  are 
  well 
  represented 
  in 
  the 
  Jackson- 
  

   Harmsworth 
  collection 
  by 
  specimens 
  from 
  Cape 
  Flora 
  and 
  Hooker 
  

   Island. 
  All 
  these 
  belong 
  to 
  one 
  type, 
  although 
  the 
  specimens 
  may 
  

   be 
  massive, 
  vesicular, 
  or 
  amygdaloidal 
  ; 
  but 
  another 
  and 
  a 
  distinct 
  

   type 
  is 
  represented 
  by 
  one 
  or 
  two 
  specimens 
  obtained 
  from 
  the 
  

   under-surface 
  of 
  an 
  iceberg 
  found, 
  tilted 
  up, 
  in 
  De 
  Bruyne 
  Sound, 
  

   between 
  Northbrook 
  and 
  Hooker 
  Islands. 
  

  

  The 
  common 
  type 
  will 
  first 
  be 
  described. 
  It 
  i< 
  represented 
  hj 
  

   specimens 
  collected 
  in 
  situ, 
  and 
  from 
  the 
  talus 
  which 
  so 
  commonly 
  

   conceals 
  the 
  lower 
  portions 
  of 
  the 
  cliffs. 
  As 
  there 
  is 
  no 
  essential 
  

   difference 
  between 
  the 
  specimens 
  collected 
  under 
  these 
  different 
  

   conditions, 
  they 
  will 
  be 
  grouped 
  together 
  for 
  purposes 
  of 
  description. 
  

   In 
  the 
  fresh 
  condition 
  the 
  rocks 
  are 
  very 
  dark, 
  almost 
  black, 
  and 
  

   of 
  medium 
  grain. 
  They 
  weather 
  in 
  the 
  manner 
  characteristic 
  of 
  

   basaltic 
  rocks, 
  and 
  sometimes 
  break 
  up 
  into 
  spheroids. 
  Examined 
  

   with 
  a 
  lens, 
  the 
  felspars 
  are 
  often 
  seen 
  to 
  be 
  of 
  a 
  yellowish 
  colour, 
  

   and 
  the 
  appearance 
  of 
  the 
  rock 
  under 
  these 
  circumstances 
  is 
  such 
  

   as 
  to 
  suggest 
  at 
  iirst 
  sight 
  that 
  olivine 
  is 
  an 
  important 
  constituent. 
  

   This, 
  however, 
  is 
  not 
  the 
  case; 
  olivine 
  does 
  occur 
  occasionall} 
  T 
  , 
  

   but 
  never 
  in 
  sufficient 
  quantity 
  to 
  affect 
  the 
  macroscopic 
  character 
  

   of 
  the 
  rock. 
  

  

  A 
  special 
  feature 
  of 
  almost 
  all 
  the 
  rocks 
  of 
  the 
  common 
  type 
  is 
  

   the 
  tendency 
  of 
  some 
  of 
  the 
  felspars 
  to 
  be 
  somewhat 
  larger 
  than 
  

   the 
  others, 
  and 
  to 
  occur 
  in 
  groups, 
  thus 
  producing 
  a 
  kind 
  of 
  

   glomero-porphyritic 
  structure. 
  A 
  few 
  specimens 
  may 
  be 
  fairly 
  

  

  