﻿210 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [Mar. 
  9, 
  

  

  In 
  Spain* 
  all 
  stages 
  of 
  the 
  Oolitic 
  series 
  are 
  poorly 
  developed. 
  

   The 
  Oxfordian 
  gives 
  to 
  it 
  its 
  chief 
  feature, 
  the 
  others 
  being 
  quite 
  rudi- 
  

   mentary. 
  In 
  the 
  Pyrenees 
  the 
  Oolite 
  is 
  distinctly 
  seen, 
  but 
  it 
  is 
  in 
  

   mere 
  fragments 
  (Leymerie). 
  

  

  The 
  Oolite 
  of 
  England 
  is 
  more 
  complete 
  and 
  better 
  characterized 
  

   than 
  in 
  most 
  other 
  countries 
  ; 
  for 
  in 
  them 
  it 
  is 
  everywhere 
  imperfect, 
  

   and 
  in 
  some 
  places 
  is 
  thin, 
  displaced, 
  and 
  even 
  scarcely 
  represented 
  ; 
  

   but 
  in 
  England 
  also, 
  rich 
  in 
  mineral 
  condition 
  and 
  fossil 
  contents 
  as 
  

   the 
  different 
  beds 
  often 
  are, 
  they 
  are 
  frequently 
  either 
  absent 
  or 
  non- 
  

   persistent. 
  All 
  along 
  the 
  coast 
  of 
  Dorsetshire 
  f, 
  and 
  indeed 
  through- 
  

   out 
  the 
  south 
  of 
  England, 
  the 
  Great 
  Oolite 
  is 
  wanting 
  ; 
  and 
  commonly 
  

   this 
  series 
  of 
  beds 
  is 
  supported 
  by 
  Lias 
  ; 
  but 
  between 
  Norton 
  Phillips 
  

   and 
  Frome 
  horizontal 
  beds 
  of 
  the 
  former 
  abut 
  against, 
  not 
  Lias 
  nor 
  

   Trias, 
  but 
  inclined 
  strata 
  of 
  Carboniferous 
  Limestone. 
  

  

  A 
  formal 
  description 
  of 
  the 
  rocks 
  of 
  this 
  epoch 
  is 
  not 
  now 
  our 
  

   object 
  ; 
  but 
  we 
  may 
  add 
  that, 
  generally 
  speaking, 
  we 
  find 
  only 
  one 
  

   of 
  the 
  stages 
  in 
  the 
  same 
  locality 
  : 
  the 
  most 
  constant, 
  as 
  has 
  already 
  

   been 
  observed, 
  is 
  the 
  Oxford 
  Clay 
  $. 
  

  

  The 
  peculiar 
  circumstances 
  attending 
  the 
  occurrence 
  of 
  the 
  Ox- 
  

   ford 
  Clay, 
  and 
  especially 
  its 
  enormous 
  range, 
  must 
  form 
  my 
  excuse 
  

   for 
  dwelling 
  on 
  it, 
  before 
  proceeding 
  to 
  point 
  out 
  some 
  blanks 
  con- 
  

   nected 
  with 
  the 
  Jurassic 
  strata. 
  

  

  The 
  Oxford 
  Clay, 
  with 
  its 
  beautiful 
  fossils, 
  which 
  are 
  said 
  by 
  

   D'Orbigny 
  § 
  to 
  be 
  identical 
  from 
  the 
  equator 
  to 
  the 
  pole, 
  is 
  spread 
  

   over 
  a 
  far 
  greater 
  geographical 
  space 
  than 
  any 
  other 
  stage 
  of 
  the 
  

   Oolitic 
  period. 
  It 
  occurs 
  all 
  through 
  Western 
  Europe, 
  in 
  England, 
  

   Italy, 
  Spain, 
  France, 
  and 
  Germany 
  || 
  . 
  Together 
  with 
  the 
  Coral-rag, 
  it 
  

   gives 
  to 
  the 
  Jura 
  Mountains^ 
  their 
  strongest 
  orographic 
  characters. 
  

   In 
  the 
  Salt 
  Range 
  of 
  the 
  Punjaub 
  ** 
  and 
  in 
  the 
  Himalayas 
  of 
  

   Northern 
  India 
  it 
  is 
  very 
  conspicuous 
  ; 
  but 
  in 
  Russia 
  it 
  particu- 
  

   larly 
  claims 
  the 
  attention 
  of 
  the 
  geologist. 
  

  

  Sir 
  Roderick 
  Murchison 
  and 
  his 
  colleagues 
  say 
  that 
  the 
  Ox- 
  

   fordian 
  is 
  almost 
  the 
  only 
  Jurassic 
  bed 
  in 
  Russia 
  ft. 
  It 
  is 
  there 
  

   capped 
  by 
  the 
  Cretaceous 
  strata, 
  and 
  lies 
  on 
  Palaeozoic 
  rocks, 
  as 
  

   near 
  Plas, 
  Mackariof, 
  and 
  Moscow 
  ; 
  and 
  whether 
  seen 
  near 
  Moscow, 
  

   on 
  the 
  Volga, 
  in 
  the 
  Oural, 
  or 
  in 
  the 
  Petchora 
  Valley, 
  &c, 
  its 
  com- 
  

   position 
  is 
  surprisingly 
  uniform. 
  It 
  is 
  always 
  very 
  thin, 
  and 
  is 
  accom- 
  

   panied 
  by 
  shreds 
  of 
  Kelloway 
  Rock, 
  Coral-rag, 
  or 
  Calcareous 
  grit. 
  

  

  Sir 
  Roderick 
  was 
  rightly 
  much 
  struck 
  by 
  the 
  simplicity, 
  uni- 
  

   formity, 
  and 
  thinness 
  of 
  the 
  Russian 
  Jurassic 
  strata, 
  which 
  doubt- 
  

   less 
  continue, 
  on 
  the 
  north-east, 
  across 
  the 
  immense 
  plains 
  on 
  the 
  

   coasts 
  of 
  the 
  Icy 
  Sea 
  to 
  New 
  Siberia, 
  and 
  extend 
  over 
  100° 
  of 
  

   longitude 
  and 
  27° 
  of 
  latitude. 
  The 
  necessarily 
  uniform 
  action 
  

   which 
  must 
  have 
  prevailed 
  over 
  this 
  vast 
  surface 
  is 
  not 
  without 
  its 
  

  

  * 
  D'Archiac, 
  ' 
  Histoire 
  des 
  Progres,' 
  vol. 
  vi. 
  pp. 
  163, 
  206. 
  

  

  t 
  Ibid. 
  vol. 
  vi. 
  p. 
  102. 
  \ 
  Ibid. 
  vol. 
  vii. 
  p. 
  699. 
  

  

  § 
  D'Orbigny, 
  'Cours 
  de 
  Paleontologie,' 
  vol. 
  ii. 
  p. 
  521. 
  

  

  || 
  D'Archiac, 
  ' 
  Histoire 
  des 
  Progres,' 
  vol. 
  vi. 
  p. 
  100. 
  

  

  f 
  Ibid. 
  pp. 
  50, 
  56, 
  57. 
  ** 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  ix. 
  p. 
  194. 
  

  

  tt 
  Geology 
  of 
  Russia, 
  vol. 
  i. 
  pp. 
  230, 
  231, 
  245, 
  247, 
  253, 
  256, 
  vol. 
  ii. 
  p. 
  428. 
  

  

  