﻿52 
  SANTA 
  MARIA 
  OIL 
  DISTRICT, 
  CALIFORNIA. 
  

  

  surface 
  vegetation. 
  Many 
  of 
  the 
  recent 
  cases 
  of 
  burning 
  are 
  directly 
  

   traceable 
  to 
  the 
  first 
  cause, 
  but 
  for 
  those 
  which 
  may 
  have 
  taken 
  place 
  

   before 
  the 
  advent 
  of 
  man 
  either 
  the 
  second 
  or 
  third 
  cause 
  will 
  have 
  

   to 
  be 
  invoked. 
  

  

  RANGE 
  IN 
  TIME 
  OF 
  THE 
  PHENOMENON. 
  

  

  As 
  already 
  mentioned, 
  the 
  marked 
  influence 
  of 
  the 
  hardened 
  shale 
  

   on 
  the 
  topography 
  in 
  certain 
  places 
  indicates 
  that 
  it 
  originated 
  in 
  

   those 
  places 
  a 
  long 
  time 
  ago. 
  The 
  age 
  of 
  some 
  of 
  the 
  burnt 
  shale 
  is 
  

   further 
  shown 
  by 
  the 
  presence 
  of 
  numerous 
  fragments 
  of 
  it 
  at 
  a 
  

   depth 
  of 
  at 
  least 
  10 
  feet 
  below 
  the 
  surface 
  in 
  horizontal 
  beds 
  of 
  Pleis- 
  

   tocene 
  age. 
  These 
  beds 
  consist 
  of 
  sand, 
  clay, 
  and 
  rough 
  gravel, 
  and 
  

   form 
  the 
  low 
  hills 
  between 
  Guadalupe 
  Lake 
  and 
  the 
  high 
  hills 
  to 
  the 
  

   west. 
  The 
  fragments 
  of 
  shale 
  are 
  little 
  worn 
  and 
  evidently 
  of 
  local 
  

   derivation, 
  having 
  possibly 
  come 
  from 
  the 
  cliffs 
  already 
  mentioned 
  

   south 
  of 
  Guadalupe. 
  The 
  fact 
  that 
  the 
  Monterey 
  shale 
  has 
  under- 
  

   gone 
  this 
  kind 
  of 
  baking 
  in 
  Pleistocene 
  as 
  well 
  as 
  in 
  recent 
  time 
  indi- 
  

   cates 
  further 
  that 
  the 
  accumulation 
  of 
  the 
  oil 
  and 
  its 
  dissemination 
  

   in 
  the 
  surface 
  rocks 
  took 
  place, 
  or 
  were 
  taking 
  place, 
  before 
  the 
  

   latest 
  orogenic 
  movements 
  in 
  this 
  coastal 
  region. 
  

  

  FERNANDO 
  FORMATION 
  (MIOCENE-PLIOCENE-PLEISTOCENE) 
  . 
  

  

  GENERAL 
  STATEMENT. 
  

  

  The 
  name 
  Fernando 
  was 
  first 
  applied 
  by 
  Homer 
  Hamlin 
  to 
  a 
  series 
  

   of 
  rocks 
  overlying 
  the 
  Monterey 
  in 
  the 
  San 
  Fernando 
  Valley, 
  Los 
  

   Angeles 
  County. 
  The 
  formation 
  has 
  since 
  been 
  recognized 
  by 
  

   Eldridge 
  and 
  Arnold 
  a 
  in 
  the 
  region 
  of 
  the 
  Puente 
  Hills, 
  Los 
  Angeles, 
  

   and 
  Santa 
  Clara 
  Valley 
  oil 
  districts, 
  where 
  it 
  is 
  a 
  series 
  of 
  unaltered 
  

   sedimentary 
  rocks 
  lying 
  unconformably 
  over 
  the 
  Monterey, 
  and 
  

   probably 
  representing 
  a 
  portion 
  of 
  upper 
  Miocene 
  time, 
  the 
  whole 
  of 
  

   the 
  Pliocene, 
  and 
  a 
  part 
  of 
  the 
  Pleistocene. 
  Its 
  lower 
  portion 
  is 
  the 
  

   equivalent 
  of 
  the 
  Santa 
  Margarita 
  and 
  Pismo 
  formations, 
  and 
  its 
  

   upper 
  portion 
  is 
  contemporaneous 
  with 
  the 
  Paso 
  Robles 
  formation, 
  

   as 
  these 
  three 
  are 
  described 
  by 
  Fairbanks 
  in 
  the 
  San 
  Luis 
  folio. 
  6 
  

  

  In 
  the 
  region 
  at 
  present 
  under 
  discussion 
  the 
  name 
  Fernando 
  is 
  

   applied 
  to 
  a 
  similar 
  formation 
  that 
  represents 
  a 
  large 
  part 
  of 
  the 
  

   Pliocene 
  and 
  probably 
  includes 
  the 
  upper 
  Miocene 
  and 
  part 
  of 
  the 
  

   lowest 
  Pleistocene. 
  It 
  consists 
  throughout 
  of 
  a 
  series 
  of 
  sandstone, 
  

   conglomerate, 
  and 
  shale 
  resting 
  unconformably 
  upon 
  the 
  Monterey. 
  

   Unconformities 
  also 
  exist 
  locally 
  within 
  the 
  Fernando. 
  It 
  attains 
  

   a 
  thickness 
  of 
  at 
  least 
  3,000 
  feet, 
  but 
  no 
  one 
  section 
  exposes 
  the 
  whole 
  

   series 
  and 
  it 
  is 
  probable 
  that 
  the 
  formation 
  includes 
  a 
  considerably 
  

   greater 
  thickness. 
  It 
  is 
  widespread 
  in 
  the 
  northern 
  part 
  of 
  Santa 
  

  

  a 
  The 
  Santa 
  Clara 
  Valley, 
  Los 
  Angeles, 
  and 
  Puente 
  Hills 
  oil 
  districts, 
  southern 
  California: 
  Bull. 
  

   U. 
  S. 
  Geol. 
  Survey 
  No. 
  309, 
  1907, 
  pp. 
  22-28. 
  

   b 
  Geologic 
  Atlas 
  U. 
  S., 
  folio 
  101, 
  U. 
  S. 
  Geol. 
  Survey, 
  1904.. 
  

  

  