﻿1804.] 
  

  

  BIGSBY 
  MISSING 
  SEDIMENTARY 
  FORMATIONS. 
  

  

  22\ 
  

  

  surface 
  polished 
  before 
  these 
  first 
  deposits 
  were 
  made, 
  and 
  as 
  it 
  were 
  

   gnawed, 
  we 
  acquire 
  a 
  certainty 
  that 
  that 
  rock 
  was 
  already 
  consoli- 
  

   dated 
  before 
  the 
  first 
  life 
  of 
  the 
  epoch 
  following 
  was 
  buried 
  there 
  ; 
  

   and 
  this 
  implies 
  a 
  considerable 
  lapse 
  of 
  time 
  between." 
  

  

  Gaps 
  are 
  the 
  most 
  numerous 
  in 
  mountainous 
  countries 
  ; 
  they 
  are, 
  

   however, 
  by 
  no 
  means 
  the 
  largest 
  there, 
  either 
  vertically 
  or 
  hori- 
  

   zontally. 
  They 
  appear 
  to 
  have 
  the 
  greatest 
  horizontal 
  extension 
  in 
  

   plains 
  ; 
  and, 
  further, 
  it 
  is 
  probably 
  true 
  that 
  the 
  vertical 
  succession 
  

   of 
  deposits 
  is 
  the 
  most 
  perfect 
  in 
  the 
  least 
  disturbed 
  districts 
  ; 
  which 
  

   we 
  see 
  (with 
  exceptions) 
  in 
  the 
  gently 
  undulating 
  regions 
  of 
  New 
  

   York 
  State, 
  and 
  on 
  the 
  west 
  side 
  of 
  the 
  Mississippi. 
  

  

  It 
  is 
  true 
  that 
  the 
  floors 
  and 
  roofs 
  of 
  gaps 
  have 
  no 
  relation 
  to 
  each 
  

   other 
  but 
  such 
  as 
  is 
  impressed 
  on 
  them 
  by 
  crust-oscillation. 
  There 
  

   is 
  complete 
  stratigraphical 
  independence 
  of 
  the 
  two 
  contiguous 
  beds 
  ; 
  

   the 
  floor 
  of 
  the 
  one 
  is 
  a 
  mere 
  support 
  to 
  the 
  other, 
  with 
  no 
  resem- 
  

   blance 
  to 
  the 
  new 
  deposit 
  either 
  in 
  mineralogy 
  or 
  in 
  fossil 
  contents. 
  

   The 
  floor 
  of 
  the 
  breach 
  remained 
  sub 
  atmospheric, 
  and 
  subject 
  only 
  

   to 
  agencies 
  already 
  noticed, 
  until 
  immersion 
  and 
  its 
  consequences 
  

   covered 
  it 
  up. 
  

  

  Table 
  A 
  will 
  be 
  found 
  useful 
  by 
  showing 
  the 
  epochal 
  relations 
  of 
  

   roof 
  and 
  floor 
  at 
  a 
  glance. 
  Their 
  total 
  absence 
  of 
  anything 
  like 
  

   connexion 
  in 
  nearly 
  all 
  cases 
  becomes 
  in 
  it 
  at 
  once 
  manifest. 
  

  

  Table 
  A. 
  — 
  Synoptical 
  View 
  of 
  the 
  Roofs 
  and 
  Floors 
  of 
  Gaps 
  in 
  their 
  

  

  Epochal 
  Relations. 
  

  

  Roofs 
  of 
  Blanks. 
  

  

  Floors 
  of 
  Blanks. 
  

  

  «5 
  

   a 
  

  

  0J 
  

  

  

  

  

  

  go 
  

  

  a 
  

  

  

   5 
  

  

  c 
  

   - 
  

   

   

  

  CB 
  

  

  a 
  

  

  

   W 
  

  

  Is 
  

  

  a 
  

  

  s 
  

  

  

   

   

   m 
  

  

  *DD 
  

  

  an 
  

   03 
  

   U 
  

  

  3 
  

  

  06 
  

  

  CD 
  

  

  c 
  

   3 
  

  

  's 
  

  

  u 
  

  

  CD 
  

  

  - 
  

  

  1 
  

  

  CO 
  

  

  13 
  

   O 
  

  

  u 
  

  

  '2 
  

   

  

  & 
  

  

  S 
  

   1 
  

  

  c 
  

  

  es 
  

  

  

   > 
  

  

  cu 
  

  

  p 
  

  

  a 
  

  

  X 
  

  

  4 
  

  

  ** 
  

  

  '3 
  

  

  N 
  

   O 
  

  

  s 
  

  

  "oS 
  

  

  Ah 
  

   1 
  

  

  c 
  

   .5 
  

   a 
  

  

  CD 
  

  

  (h 
  

  

  3 
  

   S3 
  

   Hi 
  

  

  4 
  

  

  a 
  

  

  

  

  3 
  

  

  .a* 
  

  

  O 
  

   O 
  

  

  M 
  

  

  "c3 
  

   O 
  

  

  Quaternary 
  . 
  . 
  . 
  

   Pliocene 
  

  

  1 
  

  

  1 
  

  

  1 
  

  

  1 
  

  

  T 
  

  

  

  

  

  1 
  

  

  

  16 
  

   1 
  

  

  Miocene 
  

  

  • 
  • 
  • 
  

  

  • 
  • 
  • 
  

  

  ... 
  

  

  i 
  

  

  1 
  

  

  ... 
  

  

  

  1 
  

  

  1 
  

  

  1 
  

  

  

  1 
  

  

  

  1 
  

  

  • 
  . 
  . 
  

  

  1 
  

  

  8 
  

  

  

  

  

  

  

  2 
  

  

  1 
  

  

  3 
  

  

  1 
  

  

  1 
  

  

  1 
  

  

  

  

  2' 
  

  

  2 
  

  

  

  

  13 
  

  

  Chalk 
  

  

  

  • 
  • 
  • 
  

  

  ... 
  

  

  • 
  • 
  • 
  

  

  ... 
  

  

  1 
  

  

  2 
  

  

  1 
  

  

  3 
  

  

  1 
  

  

  5 
  

  

  

  4 
  

  

  8 
  

  

  

  

  25 
  

  

  

  

  

  

  

  

  

  

  

  

  

  1 
  

  

  

  

  ... 
  

  

  1 
  

  

  

  2 
  

  

  

  

  

  

  

  

  

  5 
  

  

  1 
  

  

  1 
  

  

  1 
  

  

  6 
  

  

  . 
  . 
  . 
  

  

  i 
  

  

  1 
  

  

  

  1 
  

  

  17 
  

  

  Lias 
  

  

  

  • 
  • 
  • 
  

  

  • 
  •• 
  

  

  • 
  •• 
  

  

  ... 
  

  

  ... 
  

  

  

  

  

  

  1 
  

  

  3 
  

  

  1 
  

  

  1 
  

  

  i 
  

  

  

  7 
  

  

  Trias 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  1 
  

  

  

  1 
  

  

  

  2 
  

  

  

  

  

  

  

  

  

  

  

  

  

  6 
  

  

  

  

  ... 
  

  

  ... 
  

  

  

  6 
  

  

  Carboniferous 
  

  

  ... 
  

  

  

  

  

  

  

  

  

  

  

  2 
  

  

  4 
  

  

  31 
  

  

  

  . 
  . 
  . 
  

  

  

  37 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  9 
  

  

  

  1 
  

  

  

  10 
  

  

  

  

  

  

  

  ...... 
  

  

  

  

  

  

  

  

  3 
  

  

  

  3 
  

  

  

  6 
  

  

  No. 
  of 
  Floors 
  

  

  1 
  

  

  1 
  

  

  1 
  

  

  2 
  

  

  4J2 
  

  

  10 
  

  

  4 
  

  

  7 
  

  

  5 
  

  

  22 
  

  

  8 
  

  

  56 
  

  

  14 
  

  

  11 
  

  

  2 
  

  

  150 
  

  

  * 
  Rocks 
  of 
  doubtful 
  age 
  ; 
  but 
  below 
  Trias. 
  

  

  There 
  are, 
  however, 
  other 
  appearances 
  which 
  are 
  worthy 
  of 
  notice. 
  

   Those 
  which 
  refer 
  to 
  the 
  mineral 
  condition 
  of 
  the 
  surfaces, 
  and 
  to 
  

  

  