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  SANTA 
  MAKIA 
  OIL 
  DISTRICT, 
  CALIFORNIA. 
  

  

  LITHOLOGIC 
  CHARACTER. 
  

  

  This 
  formation 
  is 
  mapped 
  as 
  a 
  unit, 
  although 
  it 
  certainly 
  rep- 
  

   resents 
  a 
  long 
  period 
  during 
  which 
  sedimentation, 
  continuous 
  in 
  

   the 
  region 
  as 
  a 
  whole, 
  was 
  locally 
  intermittent 
  and 
  carried 
  on 
  under 
  

   differing 
  conditions, 
  owing 
  to 
  the 
  differentia] 
  elevations 
  to 
  which 
  

   the 
  region 
  was 
  subjected. 
  The 
  stratum 
  resting 
  upon 
  the 
  Monterey 
  

   in 
  one 
  place 
  is 
  apt 
  to 
  be 
  absent 
  in 
  another, 
  where 
  an 
  overlap 
  of 
  one 
  

   or 
  another 
  stratum 
  may 
  occur. 
  The 
  lowest 
  recognized 
  Fernando 
  

   rocks 
  occur 
  south 
  of 
  Sisquoc, 
  where 
  the 
  Monterey 
  is 
  overlain 
  by 
  a 
  

   bed 
  of 
  brecciated 
  and 
  waterworn 
  shale 
  derived 
  from 
  it 
  and 
  cemented 
  

   by 
  argillaceous 
  sand, 
  above 
  which 
  lies 
  about 
  200 
  feet 
  of 
  fine 
  sand, 
  

   succeeded 
  by 
  a 
  50-foot 
  layer 
  of 
  diatomaceous 
  shale 
  that 
  is 
  indistin- 
  

   guishable 
  from 
  that 
  of 
  the 
  Monterey. 
  Above 
  this 
  shale 
  the 
  series 
  

   grades 
  up 
  through 
  about 
  600 
  feet 
  of 
  fine 
  white 
  and 
  yellow 
  sand 
  and 
  

   coarse 
  sand, 
  until 
  a 
  bed 
  of 
  conglomerate 
  is 
  reached. 
  At 
  other 
  places, 
  

   as 
  south 
  of 
  Waldorf 
  and 
  south 
  of 
  Harris, 
  the 
  lowest 
  stratum 
  found 
  

   at 
  Sisquoc 
  is 
  either 
  wanting 
  or 
  of 
  minor 
  importance, 
  and 
  beds 
  of 
  dia- 
  

   tomaceous 
  shale 
  lie 
  conformably 
  over 
  the 
  Monterey 
  shale, 
  making 
  

   the 
  dividing 
  line 
  very 
  hard 
  to 
  find. 
  West 
  of 
  Waldorf 
  the 
  contact 
  

   is 
  marked 
  for 
  miles 
  by 
  a 
  bed 
  of 
  brecciated 
  Monterey 
  shale 
  of 
  coarse 
  

   and 
  fine 
  fragments, 
  in 
  places 
  cemented 
  into 
  a 
  hard 
  amalgam 
  by 
  a 
  

   paste 
  of 
  bituminous 
  material. 
  Here 
  the 
  overlying 
  beds 
  are 
  made 
  

   up 
  of 
  fine 
  shale 
  and 
  sand 
  and 
  pebbly 
  sandstone, 
  which, 
  though 
  actually 
  

   separated 
  by 
  an 
  important 
  unconformity 
  from 
  the 
  Monterey, 
  as 
  

   indicated 
  by 
  the 
  brecciated 
  zone 
  and 
  the 
  abundance 
  of 
  pebbles 
  of 
  

   that 
  formation 
  in 
  them, 
  are 
  conformable 
  in 
  dip 
  with 
  the 
  underlying 
  

   beds. 
  A 
  still 
  younger 
  series 
  of 
  fossiliferous 
  shale 
  and 
  sand 
  marks 
  

   the 
  base 
  of 
  the 
  Fernando 
  1 
  J 
  miles 
  northeast 
  of 
  Divide, 
  and 
  also 
  north- 
  

   east 
  of 
  Schumann 
  and 
  northwest 
  of 
  Mount 
  Solomon; 
  and 
  on 
  the 
  

   summit 
  of 
  the 
  ridge 
  in 
  the 
  vicinity 
  of 
  the 
  head 
  of 
  Pine 
  Canyon, 
  

   halfway 
  between 
  the 
  two 
  latter 
  localities, 
  the 
  4 
  Monterey 
  is 
  capped 
  

   by 
  what 
  appears 
  to 
  be 
  a 
  part 
  of 
  the 
  same 
  series 
  somewdiat 
  younger 
  

   still. 
  This 
  shows 
  that 
  at 
  the 
  locality 
  near 
  the 
  head 
  of 
  Pine 
  Can- 
  

   yon 
  either 
  an 
  overlap 
  of 
  the 
  late 
  Fernando 
  occurred 
  on 
  an 
  old 
  

   eminence 
  of 
  Monterey 
  shale 
  that 
  was 
  above 
  the 
  sea 
  at 
  the 
  time 
  of 
  

   the 
  deposition 
  of 
  the 
  part 
  of 
  the 
  Fernando 
  immediately 
  preceding, 
  

   causing 
  the 
  omission 
  on 
  its 
  summit 
  of 
  hundreds 
  of 
  feet 
  of 
  sedi- 
  

   ments 
  which 
  were 
  deposited 
  around 
  its 
  base; 
  or 
  else 
  the 
  portion 
  

   of 
  the 
  Fernando 
  preceding 
  this 
  series 
  was 
  removed 
  from 
  above 
  the 
  

   Monterey 
  during 
  a 
  period 
  of 
  erosion 
  within 
  Fernando 
  time, 
  this 
  

   period 
  being 
  followed 
  by 
  subsidence. 
  

  

  Along 
  the 
  ridge 
  1 
  mile 
  southeast 
  of 
  Redrock 
  Mountain, 
  in 
  the 
  

   Purisima 
  Hills, 
  there 
  is 
  a 
  capping 
  of 
  diatomaceous 
  shale 
  resembling 
  

   that 
  of 
  the 
  Monterey 
  in 
  every 
  respect, 
  but 
  containing 
  characteristic 
  

   Fernando 
  fossils. 
  It 
  w 
  r 
  as 
  not 
  suspected 
  that 
  this 
  shale 
  belonged 
  to 
  

   a 
  formation 
  distinct 
  from 
  the 
  Monterey 
  until 
  the 
  fossils 
  were 
  found. 
  

  

  