﻿io6 
  Geological 
  Survey 
  of 
  Louisiana 
  [Sect. 
  

  

  deep 
  sea 
  deposits 
  seems 
  hardly 
  well 
  explained 
  by 
  the 
  theory 
  of 
  

   the 
  common 
  time 
  origin 
  of 
  these 
  deposits. 
  The 
  Arkansas 
  

   Orange 
  Sand 
  or 
  Lafayette 
  as 
  identified 
  by 
  McGee 
  seems 
  capable 
  

   of 
  division. 
  Harris 
  found 
  a 
  portion 
  of 
  the 
  pebble 
  beds 
  passing 
  

   beneath 
  the 
  Midway 
  Eocene 
  in 
  the 
  vicinity 
  of 
  Little 
  Rock. 
  The 
  

   Plateau 
  Gravels 
  of 
  Hill 
  contain 
  Cretaceous 
  fossils 
  in 
  Clark 
  

   county, 
  and 
  Harris 
  is 
  inclined 
  to 
  regard 
  the 
  fossils 
  as 
  of 
  the 
  

   same 
  age 
  as 
  the 
  gravel. 
  

  

  Too 
  little 
  is 
  known 
  of 
  the 
  gravels 
  of 
  Louisiana 
  to 
  justify 
  any 
  

   very 
  conclusive 
  statements, 
  and 
  man}' 
  years 
  must 
  elapse 
  before 
  

   the 
  problem 
  can 
  be 
  fully 
  worked 
  out, 
  but 
  the 
  facts 
  we 
  know 
  at 
  

   present 
  seem 
  to 
  suggest 
  at 
  least 
  a 
  working 
  hypothesis. 
  The 
  

   band 
  of 
  pebbles 
  which 
  appears 
  along 
  the 
  southern 
  edge 
  of 
  the 
  

   Grand 
  Gulf 
  seems 
  to 
  pass 
  beneath 
  the 
  Port 
  Hudson 
  and 
  to 
  be 
  

   the 
  gravel 
  which 
  is 
  struck 
  in 
  deep 
  wells 
  sunk 
  in 
  the 
  Port 
  Hud- 
  

   son 
  territor5^ 
  It 
  is 
  the 
  time 
  equivalent 
  of 
  the 
  Lafayette 
  of 
  

   McGee. 
  The 
  band 
  of 
  gravel 
  which 
  follows 
  the 
  escarpment 
  

   which 
  marks 
  the 
  northern 
  limit 
  of 
  the 
  Grand 
  Gulf 
  does 
  not 
  

   extend, 
  to 
  any 
  appreciable 
  extent, 
  over 
  the 
  adjacent 
  lower 
  

   territory 
  of 
  the 
  Jackson.* 
  The 
  question 
  then 
  becomes, 
  has 
  the 
  

   time 
  since 
  the 
  deposition 
  of 
  the 
  Lafayette 
  been 
  sufficient 
  for 
  the 
  

   erosion 
  of 
  a 
  strip 
  of 
  gravel 
  several 
  miles 
  wide 
  along 
  a 
  course 
  

   which 
  cuts 
  the 
  principal 
  streams 
  at 
  right 
  angles? 
  The 
  gravel 
  

   train 
  in 
  the 
  vicinity 
  of 
  Monroe 
  lies 
  in 
  about 
  the 
  position 
  and 
  

   direction 
  of 
  the 
  shore 
  line 
  in 
  the 
  Jackson 
  period. 
  The 
  gravel 
  

   at 
  Many 
  andSabinetownis 
  in 
  about 
  the 
  position 
  of 
  the 
  Claiborne 
  

   shore-line. 
  The 
  Black 
  lake 
  bayou 
  gravel 
  train 
  occupies 
  a 
  

   questionable 
  position. 
  Much 
  of 
  it 
  lies 
  along 
  a 
  line 
  between 
  the 
  

   Lignitic 
  and 
  Lower 
  Claiborne 
  but 
  seems 
  too 
  far 
  east 
  to 
  represent 
  

   the 
  Claiborne 
  shore-line. 
  Indeed 
  if 
  the 
  gravel 
  in 
  Sec. 
  4, 
  11 
  N., 
  

   6 
  W., 
  be 
  considered 
  a 
  part 
  of 
  it, 
  it 
  is 
  younger 
  than 
  the 
  Claiborne. 
  

   We 
  are 
  hardly 
  prepared 
  to 
  affirm 
  that 
  this 
  is 
  a 
  true 
  explanation 
  

   of 
  the 
  deposition 
  of 
  the 
  gravel 
  as 
  the 
  facts 
  at 
  hand 
  are 
  entirely 
  

  

  * 
  Hopkins, 
  ist 
  Annual 
  Rept. 
  La. 
  Geol. 
  Surv., 
  p. 
  104, 
  says 
  : 
  " 
  The 
  inter- 
  

   vening 
  region 
  of 
  the 
  Jackson 
  and 
  Vicksburg 
  is 
  lower 
  ; 
  and 
  often 
  entirely 
  

   bare 
  of 
  drift 
  as 
  is 
  the 
  case 
  with 
  marly 
  regions 
  of 
  the 
  Grand 
  Gulf. 
  ' 
  When- 
  

   ever 
  the 
  northern 
  edge 
  of 
  the 
  Grand 
  Gulf 
  was 
  passed 
  by 
  the 
  present 
  

   writers 
  no 
  gravel 
  was 
  observed 
  even 
  on 
  the 
  Jackson. 
  

  

  