﻿iij 
  General 
  Geology 
  : 
  I.afayette 
  99 
  

  

  deposits. 
  The 
  material 
  which 
  has 
  been 
  lumped 
  together, 
  in 
  

   Louisiana, 
  as 
  Grand 
  Gulf 
  lies 
  between 
  the 
  Vicksburg 
  (Lower 
  

   Oligocene) 
  and 
  the 
  upper 
  Pliocene. 
  It 
  may 
  therefore 
  represent 
  

   Upper 
  Oligocene, 
  Miocene 
  or 
  Pliocene. 
  In 
  Mississippi 
  the 
  

   conditions 
  are 
  a 
  little 
  more 
  satisfactory. 
  The 
  collections 
  of 
  

   Johnson 
  at 
  Vernal 
  P. 
  O. 
  demonstrated 
  that 
  the 
  upper 
  part 
  of 
  

   Hilgard's 
  Grand 
  Gulf, 
  in 
  that 
  region, 
  is 
  Chesepeake 
  Miocene. 
  

   But 
  the 
  Alabama 
  and 
  Florida 
  sections 
  were 
  needed 
  to 
  show 
  the 
  

   age 
  of 
  the 
  Grand 
  Gulf 
  proper.* 
  It 
  has 
  there 
  been 
  shown 
  that 
  

   the 
  typical 
  Grand 
  Gulf 
  passes 
  under 
  the 
  Oak 
  Grove 
  beds, 
  and 
  

   hence 
  is 
  probably 
  equivalent 
  to 
  the 
  Chatahoochie 
  or 
  Upper 
  

   Oligocene 
  beds. 
  The 
  Grand 
  Gulf 
  beds 
  above 
  the 
  typical 
  Grand 
  

   Gulf 
  and 
  below 
  the 
  Pascagoula 
  clays 
  pass 
  into 
  the 
  Oak 
  Grove 
  

   sands, 
  which 
  are 
  now 
  regarded 
  by 
  Dall 
  as 
  transitional 
  between 
  

   the 
  Oligocene 
  and 
  Miocene. 
  f 
  

  

  LAFAYETTE 
  t 
  

  

  Historical 
  

  

  Origin 
  of 
  the 
  Term 
  Lafayette 
  

  

  The 
  attention 
  of 
  geologists 
  engaged 
  in 
  work 
  on 
  the 
  southern 
  

   coastal 
  plain 
  was 
  early 
  attracted 
  by 
  beds 
  of 
  brightly 
  colored 
  

   sands 
  and 
  gravels 
  extending 
  over 
  wide 
  areas. 
  The 
  color 
  of 
  

   these 
  deposits 
  soon 
  suggested 
  a 
  name 
  ; 
  they 
  were 
  called 
  "Orange 
  

   Sand" 
  by 
  Safford 
  in 
  1856 
  1]. 
  Hilgard 
  adopted 
  the 
  term 
  in 
  his 
  

   Mississippi 
  report 
  and 
  gave 
  the 
  most 
  complete 
  description 
  of 
  

   the 
  deposits 
  that 
  has 
  been 
  made 
  up 
  to 
  the 
  time 
  of 
  McGee's 
  

  

  * 
  Smith, 
  Geol. 
  Surv. 
  Ala., 
  1894, 
  pp. 
  104-107 
  ; 
  Dall 
  and 
  Stanley-Brown 
  

   Bull. 
  Geol. 
  Soc. 
  Am., 
  vol. 
  5, 
  p. 
  164, 
  1894. 
  

  

  f 
  A 
  Table 
  of 
  North 
  American 
  Tertiary 
  Horizons, 
  Correlated 
  with 
  One 
  

   Another 
  and 
  with 
  Those 
  of 
  the 
  Western 
  Europe, 
  with 
  Annotations 
  by 
  

   Wm. 
  H. 
  Dall, 
  iSth 
  An. 
  Rept. 
  U. 
  S. 
  Geol, 
  Surv., 
  1896-97, 
  Part 
  II, 
  p. 
  340, 
  

   1898. 
  

  

  :]: 
  See 
  article 
  by 
  W 
  J 
  McGee. 
  — 
  The 
  Lafayette 
  Formation, 
  12th 
  Ann. 
  Rept. 
  

   U. 
  S. 
  Geol. 
  Surv., 
  1891, 
  pp. 
  347-521, 
  which 
  is 
  by 
  far 
  the 
  most 
  complete 
  

   account 
  of 
  the 
  subject 
  yet 
  published. 
  

  

  II 
  Geol. 
  Recon. 
  of 
  Tenn. 
  by 
  J. 
  M. 
  Safford, 
  1856, 
  pp. 
  148-162. 
  Quoted 
  by 
  

   McGee. 
  

  

  