﻿56 
  SANTA 
  MARIA 
  OIL 
  DISTRICT, 
  CALIFORNIA. 
  

  

  STRUCTURE. 
  

  

  As 
  has 
  been 
  stated, 
  the 
  Fernando 
  is 
  generally 
  so 
  nearly 
  conform- 
  

   able 
  with 
  the 
  Monterey 
  that 
  it 
  is 
  difficult 
  to 
  draw 
  a 
  line 
  between 
  

   them 
  on 
  the 
  basis 
  of 
  a 
  discrepancy 
  in 
  dip. 
  Nevertheless, 
  it 
  is 
  in 
  

   genera] 
  true 
  thai 
  folding 
  has 
  been 
  gentler 
  in 
  the 
  Fernando 
  than 
  in 
  

   the 
  Monterey. 
  It 
  would 
  seem 
  that 
  the 
  older 
  formation 
  had 
  been 
  

   disturbed 
  in 
  varying 
  amounts, 
  in 
  some 
  places 
  severely 
  and 
  in 
  others 
  

   gently, 
  during 
  the 
  process 
  of 
  uplift 
  that 
  put 
  an 
  end 
  to 
  its 
  period 
  of 
  

   deposition. 
  As 
  a 
  result 
  the 
  dips 
  at 
  the 
  present 
  time 
  in 
  the 
  Fer- 
  

   nando 
  are 
  apt 
  to 
  be 
  less 
  steep 
  than 
  in 
  the 
  Monterey, 
  but 
  folding 
  lias 
  

   gone 
  on 
  largely 
  along 
  old 
  lines, 
  so 
  that 
  conformity 
  in 
  strike 
  between 
  

   the 
  two 
  formal 
  ions 
  is 
  the 
  rule. 
  

  

  Wide, 
  low 
  folds 
  are 
  characteristic 
  of 
  the 
  structure 
  in 
  the 
  Fernando 
  

   within 
  the 
  Santa 
  Maria 
  basin 
  region. 
  This 
  is 
  illustrated 
  by 
  the 
  

   broad 
  anticlines 
  in 
  this 
  formation 
  in 
  the 
  Solomon 
  Hills, 
  the 
  broad 
  

   anticline 
  in 
  the 
  Purisima 
  Hills, 
  and 
  the 
  synclines 
  in 
  the 
  Los 
  Alamos 
  

   and 
  Santa 
  Rita 
  valleys, 
  in 
  which 
  the 
  dips 
  range 
  from 
  5° 
  to 
  25° 
  as 
  a 
  

   rule 
  for 
  a 
  long 
  way 
  on 
  either 
  side 
  of 
  the 
  fold 
  and 
  rarely 
  become 
  

   steeper 
  than 
  30° 
  or 
  35°. 
  In 
  places, 
  as 
  south 
  and 
  west 
  of 
  Sisquoc 
  

   and 
  west 
  of 
  Canada 
  Laguna 
  Seca, 
  the 
  beds 
  are 
  almost 
  if 
  not 
  quite 
  

   horizontal, 
  but 
  this 
  is 
  exceptional. 
  Curves 
  and 
  plunges 
  in 
  the 
  pre- 
  

   existing 
  low 
  folds 
  in 
  the 
  Monterey 
  gave 
  rise 
  to 
  structural 
  basins 
  in 
  

   which 
  the 
  Fernando 
  was 
  deposited 
  as 
  a 
  filling. 
  Such 
  was 
  the 
  origin 
  

   of 
  the 
  oval 
  area 
  of 
  Fernando 
  sand 
  covering 
  the 
  eastern 
  portion 
  of 
  

   the 
  Todos 
  Santos 
  y 
  San 
  Antonio 
  grant. 
  This 
  basin 
  is 
  the 
  westward 
  

   extension 
  of 
  a 
  great 
  synclinal 
  basin 
  that 
  runs 
  from 
  that 
  locality 
  first 
  

   eastward 
  and 
  then 
  southeastward 
  across 
  the 
  Los 
  Alamos, 
  La 
  Laguna, 
  

   and 
  Corral 
  de 
  Quati 
  grants 
  and 
  has 
  determined 
  the 
  position 
  of 
  the 
  

   Los 
  Alamos 
  Valley. 
  The 
  northern 
  arm 
  of 
  this 
  syncline 
  slopes 
  grad- 
  

   ually 
  up 
  to 
  the 
  axis 
  of 
  the 
  Solomon 
  Hills, 
  and 
  the 
  southern 
  arm 
  rises 
  

   abruptly 
  into 
  the 
  Purisima 
  Hills, 
  the 
  slope 
  on 
  both 
  sides 
  conforming 
  

   with 
  the 
  topography. 
  The 
  region 
  of 
  low 
  slopes 
  covered 
  by 
  parts 
  of 
  

   the 
  Mission 
  La 
  Purisima 
  and 
  Santa 
  Rita 
  grants 
  is 
  a 
  somewhat 
  simi- 
  

   lar 
  wide 
  synclinal 
  basin 
  filled 
  with 
  soft 
  Fernando 
  sediments. 
  The 
  

   Fernando 
  is 
  steeply 
  upturned 
  along 
  the 
  northeastern 
  border 
  of 
  the 
  

   Casmalia 
  Hills, 
  where 
  it 
  stands 
  almost 
  vertically 
  in 
  contact 
  with 
  

   much 
  disturbed 
  and 
  in 
  places 
  overturned 
  beds 
  of 
  the 
  Monterey 
  

   shale. 
  It 
  is 
  upturned 
  also 
  where 
  it 
  rests 
  against 
  the 
  serpentine 
  

   north 
  of 
  Alamo 
  Pintado 
  Creek 
  on 
  the 
  La 
  Laguna 
  grant, 
  and 
  south- 
  

   west 
  of 
  Los 
  Alamos 
  it 
  seems 
  to 
  dip 
  very 
  steeply 
  under 
  the 
  brow 
  of 
  

   an 
  overturn 
  in 
  the 
  Monterey. 
  In 
  the 
  San 
  Rafael 
  Mountains 
  patches 
  

   of 
  Fernando 
  deposits 
  occur 
  as 
  remnants, 
  and 
  the 
  beds 
  in 
  many 
  

   places 
  are 
  steeply 
  folded 
  or 
  turned 
  completely 
  on 
  edge. 
  They 
  

   exhibit 
  unconformity 
  with 
  the 
  Monterey. 
  In 
  at 
  least 
  three 
  places 
  

   the 
  Fernando 
  is 
  affected 
  by 
  faulting 
  — 
  a 
  few 
  miles 
  west 
  of 
  Los 
  Ala- 
  

   mos, 
  in 
  the 
  neighborhood 
  of 
  Cebada 
  Canyon, 
  and 
  along 
  the 
  fault 
  

  

  