104  PROCEEDINGS  OE  THE  GEOLOGICAL  SOCIETY.  [May  1893. 
possibly  the  Red  Clay  of  deep-sea  investigation,  to  say  nothing  of 
deposits  which  partake  of  the  nature  of  mixtures  of  the  above.  It 
must  be  accounted  as  a  somewhat  singular  coincidence  that  this 
paper  on  the  Oceanic  Deposits  of  Barbados  should  have  been  brought 
before  the  Society  within  a  few  weeks  of  the  publication  of  the 
‘  Challenger  Report,  which  deals  in  extenso  with  the  Deep-sea 
Deposits  collected  by  the  staff  of  that  vessel  from  16  to  20  years 
ago.1  Fortunately  many  of  the  results  had  been  given  to  the  world 
in  previous  publications,  though  it  must  have  been  a  satisfaction  to 
our  Authors  to  have  been  able  to  test  their  conclusions  by  the  more 
perfected  report.  Dr.  John  Murray,  on  the  other  hand,  has  been 
able  to  refer  to  the  similarity  between  the  Barbadian  deposits  and  the 
modern  oceanic  oozes.  But  he  still  expresses  doubts  whether  the 
deposits  of  the  abysmal  areas  have  in  the  past  taken  any  part  in  the 
formation  of  the  existing  continental  masses.2  Again  he  says  that, 
with  some  doubtful  exceptions,  it  has  been  impossible  to  recognize 
in  the  rocks  of  the  continents  any  formations  identical  with  the 
pelagic  deposits.3 
Me  may,  however,  take  it  for  granted  that  in  more  than  one 
island  of  the  Caribbean  Sea  pelagic  deposits  are  now  to  be  found  as 
rock-masses  of  considerable  importance,  some  modified  in  structure, 
others  but  little  altered.  Such  being  the  case,  it  remains  to  con¬ 
sider  their  age,  and  the  inferences  connected  with  their  upheaval 
from  the  bed  of  the  sea.  If  we  may  trust  to  the  scientific 
imagination  the  story  runs  somewhat  as  follows  : — After  the  earth- 
movements  which  resulted  in  the  plication  of  the  fundamental 
series  of  ‘  continental  ’  origin,  the  area  subsided  into  depths 
appropriate  for  the  deposition  of  Globigerina- ooze,  and  so  continued 
to  subside  until  the  relative  numbers  of  the  calcareous  and  siliceous 
organisms  became  reversed,  when  finally  such  depths  were  attained 
that  siliceous  organisms  alone  remained  in  the  ooze,  which  now 
became  exclusively  Radiolarian.  The  comparative  thickness  of  the 
Radiolarian  portion  of  the  earths  is  held  to  indicate  a  long  period 
of  extreme  depth ;  but  presently  a  reverse  action  commenced,  and 
the  organic  series  ended,  as  it  began,  with  a  calcareous  deposit. 
When  the  area  again  began  to  subside,  and  the  calcareous  matter  to 
diminish  in  amount,  a  fine  argillaceous  substance,  believed  to  be 
analogous  to  the  Red  Clay  of  the  deep  sea,  was  deposited  in  lien  of 
the  Radiolarian  ooze  of  the  first  great  depression. 
1  •  Challenger’  Reports,  Deep-sea  Deposits,  Murray  and  Renard,  1891. 
2  Ibid.  p.  xxix.  3  Ibid .  p.  189. 
