﻿Vol. 
  53.] 
  ROCKS 
  AXD 
  FOSSILS 
  FROM 
  FRANZ 
  JOSEF 
  LAND. 
  515 
  

  

  Tertiary 
  period. 
  These 
  plants, 
  however, 
  nve 
  so 
  poorly 
  preserved, 
  

   and 
  their 
  place 
  of 
  origin 
  is 
  so 
  uncertain, 
  that 
  we 
  can 
  only 
  hope 
  for 
  

   additional 
  specimens 
  which 
  may 
  throw 
  light 
  upon 
  this 
  interesting 
  

   but 
  obscure 
  question. 
  

  

  VII. 
  Conclusion. 
  

  

  In 
  conclusion, 
  we 
  may 
  perhaps 
  be 
  allowed 
  to 
  sketch 
  out 
  briefly 
  

   the 
  salient 
  features 
  in 
  the 
  geological 
  history 
  of 
  Eranz 
  Josef 
  Land, 
  

   so 
  far 
  as 
  this 
  can 
  be 
  done 
  in 
  the 
  light 
  of 
  our 
  present 
  knowledge. 
  

   Passing 
  over 
  the 
  plant-bed 
  at 
  Cape 
  Stephen, 
  the 
  age 
  of 
  which 
  is 
  

   uncertain, 
  the 
  first 
  event 
  of 
  which 
  we 
  have 
  any 
  record 
  is 
  the 
  

   deposition 
  of 
  a 
  series 
  of 
  shales 
  and 
  sandstones 
  containing 
  plant- 
  

   remains, 
  beds 
  of 
  lignite, 
  and 
  other 
  evidences 
  of 
  littoral 
  or 
  estuarine 
  

   conditions. 
  Intimately 
  associated 
  with 
  these 
  shallow-water 
  deposits 
  

   are 
  some 
  purely 
  marine 
  beds, 
  the 
  age 
  of 
  which 
  is 
  placed 
  beyond 
  all 
  

   doubt 
  by 
  the 
  occurrence 
  of 
  such 
  well-characterized 
  zonal 
  fossils 
  as 
  

   Ammonites 
  macrocephalus 
  and 
  A. 
  modiolaris. 
  

  

  Owing 
  mainly 
  to 
  the 
  brilliant 
  researches 
  of 
  Neumayr, 
  1 
  it 
  is 
  now 
  

   generally 
  recognized 
  that 
  the 
  Jurassic 
  sea 
  reached 
  its 
  greatest 
  

   extension 
  in 
  the 
  present 
  land-areas 
  during 
  the 
  Callovian 
  and 
  

   Oxfordian 
  periods. 
  Hydrocratic 
  and 
  geocratic 
  movements 
  alter- 
  

   nated 
  during 
  Jurassic 
  times, 
  with 
  a 
  decided 
  balance 
  in 
  favour 
  of 
  the 
  

   former, 
  and 
  a 
  recession 
  of 
  the 
  coast-line 
  towards 
  the 
  north. 
  Even 
  

   in 
  the 
  North 
  of 
  Scotland 
  we 
  find 
  no 
  decided 
  evidence 
  of 
  the 
  

   proximity 
  of 
  land 
  during 
  the 
  Oxfordian 
  period, 
  although 
  the 
  lower 
  

   portions 
  of 
  the 
  Jurassic 
  formation 
  are 
  represented 
  by 
  littoral 
  and 
  

   estuarine 
  deposits. 
  2 
  

  

  Under 
  these 
  circumstances 
  the 
  discovery 
  of 
  A. 
  macrocephalus-beds 
  

   in 
  Eranz 
  Josef 
  Land 
  iu 
  association 
  with 
  plant-bearing 
  strata 
  is 
  of 
  

   special 
  interest. 
  It 
  extends 
  the 
  range 
  of 
  this 
  ammonite 
  several 
  

   degrees 
  towards 
  the 
  north, 
  and 
  shows, 
  in 
  all 
  probability, 
  that 
  

   during 
  the 
  period 
  of 
  its' 
  existence 
  a 
  coast-line 
  lay 
  somewhere 
  in 
  this 
  

   direction. 
  Marine 
  deposits 
  of 
  Callovian 
  and 
  Oxfordian 
  age 
  are 
  now 
  

   known 
  to 
  range 
  from 
  Sutherland 
  to 
  Cutch 
  and 
  from 
  Eranz 
  Josef 
  

   Land 
  to 
  the 
  North 
  of 
  Africa 
  ; 
  and 
  A. 
  macrocephalus 
  is 
  one 
  of 
  the 
  

   most 
  widely 
  distributed 
  of 
  all 
  Jurassic 
  ammonites. 
  3 
  The 
  soft 
  

   Jurassic 
  sediments 
  were 
  subsequently 
  covered 
  up 
  and 
  preserved 
  

   from 
  destruction 
  by 
  vast 
  flows 
  of 
  basaltic 
  lava 
  ; 
  and 
  it 
  is 
  not 
  a 
  little 
  

   remarkable 
  that 
  rocks 
  of 
  the 
  same 
  general 
  period 
  have 
  been 
  

   preserved 
  in 
  the 
  same 
  way 
  in 
  districts 
  so 
  far 
  removed 
  from 
  Franz 
  

  

  1 
  ' 
  Die 
  geographische 
  Verbreitung 
  der 
  Juraforination,' 
  Denkschr. 
  d. 
  k. 
  Akad. 
  

   d. 
  Wiss. 
  Wien, 
  vol. 
  1. 
  (1885) 
  pp. 
  57-142. 
  

  

  2 
  J. 
  W. 
  Judd, 
  ' 
  The 
  Secondary 
  Rocks 
  of 
  Scotland,' 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  

   vol. 
  xxix. 
  (1873) 
  p. 
  164, 
  & 
  vol. 
  xxxiv. 
  (1878) 
  p. 
  726. 
  

  

  3 
  It 
  not 
  only 
  occurs 
  in 
  Central 
  and 
  Southern 
  Europe, 
  Northern 
  Russia, 
  and 
  

   Franz 
  Josef 
  Land, 
  but 
  also 
  in 
  Cutch 
  (Waageu, 
  Pal. 
  Indica, 
  ser. 
  ix. 
  vol. 
  i. 
  1873) 
  and 
  

   Bolivia 
  (Steinmann, 
  Neues 
  Jahrb., 
  Beilage-Band 
  i. 
  1881, 
  p. 
  239). 
  It 
  has 
  also 
  been 
  

   recorded 
  from 
  Western 
  Australia 
  (Moore, 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xxvi. 
  

   1870, 
  p. 
  226), 
  but 
  Neuinayr 
  throws 
  doubt 
  on 
  the 
  identification 
  (op. 
  cit. 
  p. 
  118). 
  

  

  2m 
  2 
  

  

  