﻿^°1- 
  53*] 
  ROCKS 
  AND 
  FOSSILS 
  FROM 
  FRANZ 
  JOSEF 
  LAND. 
  509 
  

  

  It 
  is 
  difficult 
  to 
  assign 
  any 
  age 
  to 
  this 
  wood. 
  It 
  is 
  possible 
  that 
  

   a 
  Tertiary 
  basalt 
  overwhelmed 
  forests 
  of 
  pines 
  growing 
  at 
  that 
  

   time, 
  and 
  that 
  the 
  same 
  kind 
  of 
  trees 
  subsequently 
  grew 
  on 
  the 
  

   surface 
  of 
  the 
  sheets 
  of 
  basalt. 
  Or 
  it 
  may 
  be 
  that 
  some 
  already 
  

   existing 
  plant-beds 
  were 
  invaded 
  by 
  the 
  intruding 
  basalt, 
  in 
  which 
  

   case 
  the 
  moving 
  mass 
  might 
  in 
  some 
  instances 
  have 
  passed 
  over, 
  

   and 
  in 
  others 
  passed 
  under, 
  the 
  plant-bed 
  ; 
  or 
  there 
  may 
  have 
  been 
  

   more 
  than 
  one 
  such 
  bed. 
  

  

  It 
  is 
  well-nigh 
  certain 
  that 
  this 
  silicified 
  wood 
  is 
  not 
  earlier 
  than 
  

   Upper 
  Jurassic, 
  for 
  it 
  almost 
  certainly 
  occupies 
  a 
  position 
  above 
  the 
  

   Oxfordian 
  fossil-bed 
  ; 
  but 
  of 
  this 
  we 
  have 
  no 
  positive 
  proof, 
  seeing 
  

   that 
  the 
  beds 
  exposed 
  at 
  Cape 
  Gertrude 
  have 
  yielded 
  no 
  fossils 
  to 
  

   indicate 
  their 
  age. 
  It 
  is 
  quite 
  possible, 
  therefore, 
  that 
  some 
  of 
  

   this 
  silicified 
  wood 
  may 
  be 
  of 
  Upper 
  Jurassic, 
  Cretaceous, 
  or 
  Tertiary 
  

   age. 
  On 
  the 
  whole, 
  it 
  seems 
  most 
  in 
  accordance 
  with 
  the 
  known 
  

   facts 
  to 
  regard 
  it 
  as 
  of 
  approximately 
  the 
  same 
  age 
  as 
  the 
  basalts, 
  

   which 
  are 
  probably 
  of 
  Tertiary 
  date. 
  

  

  Judging 
  from 
  the 
  report 
  of 
  Mr. 
  Leigh 
  Smith's 
  visit 
  to 
  Franz 
  

   Josef 
  Land, 
  1 
  and 
  Mr. 
  Etheridge's 
  remarks 
  in 
  the 
  discussion, 
  2 
  

   it 
  was 
  thought 
  that 
  the 
  pine-cone, 
  the 
  silicified 
  wood, 
  and 
  the 
  

   plant-impressions 
  there 
  mentioned 
  were 
  all 
  from 
  (me 
  horizon; 
  

   but 
  no 
  evidence 
  was 
  brought 
  forward 
  proving 
  that 
  such 
  was 
  the 
  

   case. 
  Mr. 
  Carruthers, 
  who 
  examined 
  the 
  pine-cone, 
  was 
  of 
  opinion 
  

   that 
  it 
  was 
  of 
  Cretaceous 
  age 
  ; 
  and 
  the 
  presence 
  of 
  Cretaceous 
  rocks 
  

   in 
  Franz 
  Josef 
  Land 
  rests 
  upon 
  that 
  opinion. 
  It 
  is 
  by 
  no 
  means 
  

   clear, 
  however, 
  that 
  the 
  silicified 
  wood 
  is 
  Cretaceous, 
  even 
  if 
  the 
  

   evidence 
  of 
  the 
  pine-cone 
  be 
  accepted; 
  but 
  there 
  now 
  seems 
  to 
  

   be 
  some 
  doubt 
  as 
  to 
  the 
  age 
  of 
  the 
  cone. 
  

  

  The 
  manner 
  in 
  which 
  this 
  silicified 
  wood 
  is 
  preserved 
  merits 
  

   attention 
  ; 
  in 
  some 
  cases 
  the 
  replacement 
  by 
  silica 
  has 
  been 
  so 
  

   brought 
  about 
  that 
  the 
  form 
  of 
  the 
  finest 
  tissues 
  is 
  extremely 
  well 
  

   preserved, 
  and, 
  being 
  of 
  a 
  dark 
  brown 
  colour, 
  sections 
  under 
  the 
  

   microscope 
  show 
  their 
  structure 
  even 
  better 
  than 
  recent 
  wood 
  

   (PL 
  XLI, 
  fig. 
  11). 
  The 
  large 
  longitudinal 
  cells 
  of 
  the 
  woody 
  tissue 
  

   are 
  clearly 
  defined, 
  as 
  are 
  also 
  the 
  medullary 
  rays 
  which 
  cross 
  

   them, 
  but 
  the 
  feature 
  w 
  7 
  hich 
  is 
  the 
  most 
  striking 
  and 
  at 
  the 
  same 
  

   time 
  the 
  most 
  characteristic 
  is 
  the 
  well-marked 
  series 
  of 
  discs 
  

   (dotted 
  tissue) 
  which 
  are 
  typical 
  of 
  coniferous 
  wood, 
  and 
  are 
  in 
  

   this 
  instance 
  large, 
  and 
  arranged 
  in 
  single 
  and 
  double 
  rows 
  in 
  the 
  

   cells. 
  Transverse 
  sections 
  show 
  the 
  usual 
  annual 
  rings. 
  

  

  There 
  is 
  much 
  difference 
  in 
  the 
  degree 
  in 
  which 
  the 
  finer 
  tissues 
  

   of 
  this 
  fossil 
  wood 
  are 
  preserved, 
  some 
  examples, 
  like 
  that 
  above 
  

   described, 
  seeming 
  to 
  have 
  every 
  feature 
  of 
  the 
  original 
  structure 
  

   retained, 
  while 
  in 
  others 
  this 
  is 
  nearly 
  or 
  quite 
  obliterated. 
  Some 
  

   sections 
  of 
  black 
  flinty 
  fragments 
  which 
  have 
  been 
  examined 
  

   have 
  traces 
  of 
  tissue 
  so 
  faint 
  as 
  to 
  leave 
  doubt 
  concerning 
  its 
  

   vegetable 
  origin 
  ; 
  and 
  there 
  are 
  many 
  intermediate 
  stages 
  between 
  

   the 
  two 
  extremes. 
  It 
  may 
  be 
  mentioned 
  also 
  that 
  silicified 
  masses 
  

  

  1 
  Proc. 
  Eov. 
  Geogr. 
  Soc. 
  n. 
  s. 
  toI. 
  iii. 
  (1881) 
  p. 
  135. 
  

  

  2 
  Ibid. 
  p. 
  147. 
  

  

  