﻿GEOLOGY. 
  31 
  

  

  shale 
  is 
  mentioned 
  by 
  H. 
  W. 
  Fairbanks 
  in 
  the 
  two 
  quotations 
  given 
  

   under 
  the 
  heading 
  " 
  Previous 
  knowledge 
  of 
  the 
  geology, 
  " 
  pages 
  12-13, 
  

   and 
  this 
  author 
  discusses 
  them 
  further 
  in 
  his 
  paper 
  there 
  cited. 
  

  

  STRUCTURE 
  AND 
  THICKNESS. 
  *&> 
  

  

  Like 
  all 
  the 
  Tertiary 
  and 
  pre-Tertiary 
  formations 
  of 
  this 
  region 
  

   the 
  deposits 
  under 
  discussion 
  have 
  been 
  subjected 
  to 
  folding 
  that 
  

   has 
  left 
  none 
  of 
  them 
  in 
  an 
  undisturbed 
  attitude. 
  But 
  as 
  they 
  con- 
  

   sist 
  in 
  large 
  part 
  of 
  soft 
  sandstone 
  and 
  conglomerate 
  with 
  inter- 
  

   bedded 
  layers 
  of 
  sandstone 
  and 
  clayey 
  shale, 
  they 
  have 
  not 
  been 
  so 
  

   violently 
  fractured 
  and 
  disturbed 
  as 
  much 
  of 
  the 
  brittle 
  shale 
  of 
  the 
  

   lower 
  portion 
  of 
  the 
  Monterey 
  (middle 
  Miocene). 
  The 
  high 
  ridge 
  of 
  

   the 
  Santa 
  Ynez 
  Mountains 
  from 
  Point 
  Conception 
  eastward 
  is 
  formed 
  

   by 
  a 
  great 
  monocline 
  in 
  the 
  sandstone 
  of 
  this 
  terrane, 
  dipping 
  toward 
  

   the 
  sea 
  on 
  the 
  south 
  at 
  an 
  angle 
  of 
  about 
  30°. 
  North 
  of 
  this 
  ridge 
  

   occurs 
  a 
  longitudinal 
  depression 
  in 
  the 
  range 
  in 
  which 
  the 
  folds 
  of 
  

   the 
  beds 
  are 
  rather 
  low; 
  and 
  still 
  farther 
  north, 
  bordering 
  the 
  Santa 
  

   Ynez 
  Yalley, 
  these 
  rocks 
  are 
  considerably 
  disturbed, 
  dipping 
  in 
  

   various 
  directions 
  and 
  at 
  all 
  angles 
  between 
  15° 
  and 
  the 
  vertical. 
  

   The 
  general 
  inclination 
  of 
  the 
  beds 
  on 
  the 
  north 
  side, 
  however, 
  is 
  

   northward, 
  the 
  structure 
  of 
  this 
  part 
  of 
  the 
  range, 
  broadly 
  viewed, 
  

   being 
  anticlinal. 
  In 
  the 
  San 
  Rafael 
  Mountains 
  the 
  Yaqueros 
  strata 
  

   are 
  steeply 
  folded 
  along 
  northwest-southeast 
  lines, 
  in 
  conformity 
  

   with 
  the 
  overlying 
  Monterey. 
  A 
  marked 
  example 
  of 
  the 
  way 
  in 
  

   which 
  the 
  soft, 
  coarse 
  conglomerate 
  has 
  been 
  left 
  little 
  affected 
  

   occurs 
  in 
  Buckhorn 
  Canyon, 
  where 
  thick 
  beds 
  of 
  this 
  rock, 
  probably 
  

   the 
  basal 
  part 
  of 
  the 
  Yaqueros, 
  lie 
  almost 
  horizontal. 
  

  

  The 
  Tejon-Sespe-Yaqueros 
  rocks 
  have 
  a 
  thickness 
  of 
  at 
  least 
  5,000 
  

   feet 
  in 
  the 
  Santa 
  Ynez 
  Mountains, 
  and 
  further 
  work 
  will 
  probably 
  

   allow 
  these 
  figures 
  to 
  be 
  considerably 
  increased. 
  

  

  AGE 
  AND 
  FOSSILS. 
  

  

  At 
  least 
  two 
  distinct 
  faunas 
  are 
  found 
  in 
  the 
  Tejon-Sespe-Ya- 
  

   queros 
  strata. 
  The 
  lower 
  is 
  characteristically 
  Eocene, 
  and 
  similar 
  

   to 
  that 
  of 
  the 
  Tejon 
  formation 
  of 
  the 
  type 
  locality; 
  the 
  upper 
  con- 
  

   tains 
  many 
  of 
  the 
  species 
  found 
  at 
  the 
  type 
  locality 
  of 
  the 
  Vaqueros 
  

   formation, 
  which 
  is 
  the 
  standard 
  lower 
  Miocene 
  of 
  the 
  central 
  Cali- 
  

   fornia 
  province. 
  So 
  far 
  as 
  is 
  definitely 
  known 
  no 
  species 
  bridges 
  

   the 
  gap 
  between 
  these 
  two 
  faunas, 
  either 
  here 
  or 
  elsewhere 
  in 
  Cali- 
  

   fornia, 
  although 
  the 
  beds 
  containing 
  the 
  two 
  are 
  apparently 
  con- 
  

   formable 
  not 
  only 
  in 
  the 
  Santa 
  Ynez 
  Range 
  but 
  also 
  locally 
  as 
  far 
  

   north 
  as 
  Martinez, 
  east 
  of 
  San 
  Francisco 
  Bay. 
  

  

  