﻿784 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [26] 
  

  

  abundance 
  of 
  these 
  materials, 
  which 
  are 
  so 
  characteristic 
  of 
  a 
  true 
  red 
  

   clay, 
  as 
  being 
  a 
  measure 
  of 
  the 
  relative 
  rate 
  of 
  accumulation 
  of 
  the 
  ma- 
  

   rine 
  sediments 
  in 
  which 
  they 
  lie. 
  The 
  terrigenous 
  deposits 
  accumulate 
  

   most 
  rapidly 
  ; 
  then 
  follow 
  in 
  order 
  Pteropod 
  ooze, 
  Globigerina 
  ooze, 
  

   Diatom 
  ooze, 
  Kadiolarian 
  ooze, 
  and, 
  slowest 
  of 
  all, 
  red 
  clay. 
  

  

  From 
  the 
  data 
  now 
  advanced 
  it 
  appears 
  possible 
  to 
  deduce 
  other 
  

   conclusions 
  important 
  from 
  a 
  geological 
  point 
  of 
  view. 
  In 
  the 
  deposits 
  

   due 
  essentially 
  to 
  the 
  action 
  of 
  the 
  ocean 
  we 
  are 
  at 
  once 
  struck 
  by 
  the 
  

   great 
  variety 
  of 
  sediments 
  which 
  may 
  accumulate 
  in 
  regions 
  where 
  the 
  

   external 
  conditions 
  are 
  almost 
  identical. 
  Again, 
  marine 
  faunas 
  and 
  

   floras, 
  at 
  least 
  those 
  of 
  the 
  surface, 
  differ 
  greatly, 
  both 
  with 
  respect 
  to 
  

   species 
  and 
  to 
  relative 
  abundance 
  of 
  individuals, 
  in 
  different 
  regions 
  of 
  

   the 
  ocean 
  ; 
  and 
  as 
  their 
  remains 
  determine 
  the 
  character 
  of 
  the 
  deposit 
  

   in 
  many 
  instances, 
  it 
  is 
  legitimate 
  to 
  conclude 
  that 
  the 
  occurrence 
  of 
  

   organisms 
  of 
  a 
  different 
  nature 
  in 
  several 
  beds 
  is 
  not 
  an 
  argument 
  

   against 
  the 
  synchronism 
  of 
  the 
  layers 
  which 
  contain 
  them. 
  

  

  The 
  small 
  extent 
  occupied 
  by 
  littoral 
  formations, 
  especially 
  those 
  of 
  

   an 
  arenaceous 
  nature, 
  shown 
  by 
  our 
  investigations, 
  and 
  the 
  relatively 
  

   slow 
  rate 
  at 
  which 
  such 
  deposits 
  are 
  formed 
  along 
  a 
  stable 
  coast, 
  are 
  

   matters 
  of 
  importance. 
  

  

  In 
  the 
  present 
  state 
  of 
  things 
  there 
  does 
  not 
  appear 
  to 
  be 
  anything 
  

   to 
  account 
  for 
  the 
  enormous 
  thickness 
  of 
  the 
  clastic 
  sediments 
  making 
  

   up 
  certain 
  geological 
  formations, 
  unless 
  we 
  consider 
  the 
  exceptional 
  

   cases 
  of 
  erosion 
  which 
  are 
  brought 
  into 
  play 
  when 
  a 
  coast 
  is 
  undergoing 
  

   constant 
  elevation 
  or 
  subsidence. 
  

  

  Great 
  movements 
  of 
  the 
  land 
  are 
  doubtless 
  necessary 
  for 
  the 
  forma- 
  

   tion 
  of 
  thick 
  beds 
  of 
  transported 
  matter 
  like 
  sandstones 
  and 
  conglom- 
  

   erates. 
  

  

  In 
  this 
  connection 
  may 
  be 
  noted 
  the 
  fact 
  that 
  in 
  certain 
  regions 
  of 
  the 
  

   deep 
  sea 
  no 
  appreciable 
  formation 
  is 
  now 
  taking 
  place 
  ; 
  hence 
  the 
  ab- 
  

   sence 
  in 
  the 
  sedimentary 
  series 
  of 
  a 
  layer 
  representing 
  a 
  definite 
  hori- 
  

   zon 
  must 
  not 
  always 
  be 
  interpreted 
  as 
  proof 
  either 
  of 
  the 
  emergence 
  of 
  

   the 
  bottom 
  of 
  the 
  sea 
  during 
  the 
  corresponding 
  period 
  or 
  of 
  an 
  ulterior 
  

   erosion. 
  Arenaceous 
  formations 
  of 
  great 
  thickness 
  require 
  seas 
  of 
  no 
  

   great 
  extent 
  and 
  coasts 
  subject 
  to 
  frequent 
  oscillations, 
  which 
  permit 
  

   the 
  shores 
  to 
  advance 
  and 
  retire. 
  Along 
  these, 
  through 
  all 
  periods 
  of 
  

   the 
  earth's 
  history, 
  the 
  great 
  marine 
  sedimentary 
  x)henomena 
  have 
  

   taken 
  place. 
  

  

  The 
  continental 
  geological 
  formations, 
  when 
  compared 
  with 
  marine 
  

   deposits 
  of 
  modern 
  seas 
  and 
  oceans, 
  present 
  no 
  analogues 
  to 
  the 
  red 
  

   clays, 
  Kadiolarian, 
  Globigerina, 
  Pteropod, 
  and 
  Diatom 
  oozes. 
  On 
  the 
  

   other 
  hand, 
  the 
  terrigenous 
  deposits 
  of 
  our 
  lakes, 
  shallow 
  seas, 
  in- 
  

   closed 
  seas, 
  and 
  the 
  shores 
  of 
  the 
  continents 
  reveal 
  the 
  equivalents 
  of 
  

   our 
  chalks, 
  green 
  sands, 
  sandstones, 
  conglomerates, 
  shales, 
  marls, 
  and 
  

   other 
  sedimentary 
  formations. 
  Such 
  formation 
  as 
  certain 
  Tertiary 
  de- 
  

   posits 
  of 
  Italy, 
  Kadiolarian 
  earth 
  from 
  liarbadoes, 
  and 
  portions 
  of 
  the 
  

  

  