﻿1864.] 
  SEELEY 
  HUNSTANTON 
  RED 
  ROCK. 
  331 
  

  

  But 
  there 
  are 
  no 
  data 
  for 
  assuming 
  that 
  the 
  old 
  Cretaceous 
  lands 
  

   sank 
  dowu 
  more 
  uniformly 
  than 
  we 
  see 
  them 
  descending 
  now. 
  

   Every 
  one 
  knows 
  the 
  irregularity 
  of 
  the 
  rise 
  of 
  Sweden, 
  South 
  America, 
  

   and 
  other 
  countries 
  ; 
  and 
  it 
  appears 
  more 
  than 
  possible 
  that 
  the 
  thick 
  

   rock 
  of 
  one 
  place 
  and 
  the 
  thin 
  bed 
  of 
  another 
  are 
  often 
  consequences 
  

   of 
  such 
  a 
  cause 
  as 
  this, 
  and 
  therefore 
  that 
  a 
  deposit 
  may 
  have 
  been 
  

   wholly 
  built 
  up 
  in 
  one 
  district 
  before 
  even 
  its 
  foundation-stone 
  

   was 
  dropped 
  in 
  another. 
  Hence 
  it 
  must 
  sometimes 
  happen, 
  from 
  a 
  

   gradational 
  movement 
  in 
  the 
  sea-bottom, 
  that 
  the 
  rock 
  of 
  one 
  age 
  

   will 
  continue 
  to 
  be 
  deposited 
  during 
  a 
  succeeding 
  period. 
  In 
  a 
  

   former 
  paper* 
  the 
  author 
  endeavoured 
  to 
  show 
  that 
  the 
  sand 
  at 
  

   Huns'ton, 
  like 
  the 
  clay 
  at 
  Speeton, 
  represents 
  two 
  formations, 
  and 
  

   therefore 
  that 
  the 
  formation 
  Carstone 
  is 
  not 
  merely 
  Shanklin 
  sands, 
  

   but 
  Gault 
  too. 
  

  

  When 
  the 
  upper 
  part 
  of 
  the 
  Red 
  Rock 
  is 
  compared 
  with 
  the 
  

   sponge-layer 
  above, 
  the 
  difficulties 
  are 
  not 
  so 
  great 
  ; 
  for, 
  besides 
  

   mineral 
  resemblance, 
  there 
  is 
  in 
  both 
  beds 
  an 
  organic 
  growth, 
  known 
  

   as 
  Spongia 
  paradoxica, 
  which 
  seems 
  to 
  point 
  conclusively 
  to 
  the 
  

   upper 
  bed 
  being 
  immediately 
  subsequent 
  in 
  time. 
  In 
  one 
  place 
  I 
  

   thought 
  I 
  traced 
  an 
  individual 
  growing 
  out 
  of 
  the 
  lower 
  bed 
  into 
  

   the 
  upper 
  one 
  ; 
  and 
  if 
  the 
  existence 
  of 
  this 
  fossil, 
  which 
  forms 
  no 
  

   small 
  part 
  of 
  the 
  bulk 
  of 
  both 
  beds, 
  may 
  be 
  taken 
  as 
  evidence 
  that 
  

   both 
  bed 
  No. 
  1 
  and 
  the 
  sponge-rock 
  belong 
  to 
  the 
  same 
  geological 
  

   formation, 
  the 
  sponge-rock 
  must 
  be 
  regarded 
  as 
  a 
  subordinate 
  bed 
  

   of 
  the 
  Huns'ton 
  Rock. 
  All 
  that 
  sections 
  like 
  fig. 
  1, 
  where 
  the 
  

   sponge-rock 
  seems 
  to 
  be 
  part 
  of 
  the 
  chalk, 
  can 
  indicate 
  is 
  that, 
  at 
  the 
  

   time 
  when 
  those 
  agencies 
  which 
  produced 
  the 
  cracks 
  and 
  slips 
  were 
  

   operating, 
  there 
  already 
  existed 
  a 
  film 
  of 
  yielding 
  matter 
  between 
  

   the 
  red 
  and 
  white 
  sponge-beds, 
  allowing 
  the 
  latter 
  less 
  compact 
  

   deposit 
  space 
  to 
  bend 
  rather 
  than 
  break. 
  

  

  The 
  thin 
  band 
  of 
  red 
  chalk 
  enclosed 
  in 
  the 
  white 
  does 
  not 
  indi- 
  

   cate 
  that 
  it 
  and 
  the 
  intervening 
  chalk 
  must 
  be 
  grouped 
  with 
  the 
  

   Red 
  Rock 
  below. 
  Yet, 
  as 
  the 
  agencies 
  producing 
  the 
  colour 
  appear 
  

   to 
  have 
  been 
  the 
  same, 
  it 
  may 
  indicate 
  that 
  they 
  continued 
  operating 
  

   in 
  other 
  seas 
  for 
  ages 
  after 
  the 
  consolidation 
  of 
  the 
  inferior 
  strata, 
  

   and 
  therefore 
  that 
  they 
  may 
  be 
  a 
  link 
  between 
  the 
  Huns'ton 
  Rock 
  

   and 
  the 
  Chalk. 
  But, 
  after 
  all, 
  it 
  is 
  of 
  very 
  little 
  importance 
  ; 
  and 
  

   occasional 
  shifting 
  of 
  the 
  sand 
  on 
  the 
  shore 
  exposes 
  a 
  band 
  of 
  bright 
  

   red 
  clay 
  in 
  the 
  Carstone, 
  of 
  unknown 
  thickness, 
  but 
  certainly 
  limited 
  

   extent, 
  which 
  might 
  be 
  regarded 
  as 
  having 
  a 
  relation 
  to 
  the 
  Huns'ton 
  

   Rock 
  similar 
  to 
  that 
  of 
  the 
  red 
  chalk. 
  

  

  In 
  another 
  paper 
  f 
  I 
  have 
  endeavoured 
  to 
  show 
  that 
  the 
  Gault 
  is 
  

   unconformable 
  to 
  the 
  Shanklin 
  sands 
  in 
  this 
  district, 
  and 
  that 
  the 
  

   Upper 
  Greensand 
  is 
  not 
  conformable 
  to 
  the 
  Gault. 
  The 
  Chalk 
  and 
  

   Upper 
  Greensand 
  are 
  perfectly 
  conformable. 
  By 
  the 
  help 
  of 
  these 
  

   facts 
  the 
  age 
  of 
  the 
  Huns'ton 
  Red 
  Rock 
  may 
  be 
  gathered. 
  

  

  * 
  "On 
  the 
  Significance 
  of 
  Rocks 
  and 
  Fossils." 
  Read 
  before 
  the 
  Cambridge 
  

   Philosophical 
  Society. 
  

  

  f 
  " 
  On 
  a 
  Section 
  discovering 
  the 
  Cretaceous 
  Beds 
  at 
  Ely." 
  Read 
  before 
  the 
  

   Cambridge 
  Philosophical 
  Society. 
  

  

  