﻿62 
  REPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  bluff 
  the 
  greater 
  part 
  of 
  its 
  salt 
  is 
  taken. 
  Above 
  this 
  point 
  the 
  water 
  

   is 
  clear 
  and 
  fresh. 
  On 
  either 
  side 
  of 
  the 
  exit 
  the 
  rocks 
  dip 
  to 
  the 
  north- 
  

   east, 
  the 
  angle 
  at 
  the 
  base 
  of 
  the 
  wall 
  being 
  25°. 
  This 
  decreases 
  as, 
  

   we 
  go 
  up, 
  and 
  also 
  as 
  we 
  go 
  toward 
  the 
  Dolores. 
  Massive 
  deep-red 
  

   sandstones 
  form 
  the 
  capping 
  of 
  the 
  bluffs. 
  Between 
  the 
  basin 
  and 
  the 
  

   Dolores 
  there 
  are 
  remnants 
  of 
  Jurassic 
  strata. 
  Salt 
  Creek 
  is 
  in 
  caQon 
  

   from 
  Sindbad's 
  Valley 
  to 
  the 
  Dolores. 
  Crossing 
  to 
  the 
  west 
  side 
  of 
  the 
  

   basin, 
  we 
  find 
  light-yellowish 
  sand, 
  shales, 
  and 
  limestones, 
  the 
  latter 
  fos- 
  

   siliferous, 
  beneath 
  the 
  red 
  shales 
  and 
  pink 
  conglomeritic 
  beds. 
  They 
  

   dip 
  to 
  the 
  northeast 
  at 
  an 
  angle 
  of 
  60°, 
  seeming 
  to 
  jut 
  up 
  against 
  the 
  

   red 
  beds 
  which 
  here 
  form 
  the 
  bluffs, 
  and 
  dip 
  south 
  of 
  west 
  at 
  an 
  angle 
  of 
  

   10°, 
  decreasing 
  as 
  we 
  go 
  toward 
  the 
  mountain, 
  until 
  we 
  reach 
  the 
  axis 
  

   of 
  a 
  fold, 
  beyond 
  which 
  the 
  strata 
  again 
  rise, 
  dipping 
  from 
  the 
  mountains. 
  

  

  The 
  northeastern 
  portion 
  of 
  the 
  Sierra 
  la 
  Sal 
  is 
  drained 
  by 
  a 
  creek 
  

   flowing 
  east 
  and 
  north 
  to 
  the 
  Dolores. 
  It 
  rises 
  among 
  the 
  peaks 
  about 
  

   stations 
  65 
  and 
  66, 
  and 
  receives 
  a 
  branch 
  from 
  the 
  park-like 
  country 
  at 
  

   the 
  base 
  of 
  the 
  mountains. 
  It 
  soon 
  begins 
  to 
  cut 
  deeply 
  into 
  the 
  rocks, 
  

   joining 
  the 
  Dolores 
  in 
  deep 
  caiion. 
  Between 
  this 
  stream 
  and 
  Salt 
  Creek 
  

   there 
  are 
  a 
  number 
  of 
  minor 
  gulches 
  whose 
  streams 
  flow 
  into 
  the 
  Dolores. 
  

   The 
  largest 
  of 
  these 
  rises 
  on 
  the 
  plateau 
  opposite 
  one 
  of 
  the 
  heads 
  of 
  

   Salt 
  Creek 
  and 
  goes 
  ioto 
  the 
  Dolores 
  nearly 
  opposite 
  the 
  mouth 
  of 
  the 
  

   stream 
  from 
  the 
  Unaweep 
  Caiion. 
  It 
  separates 
  two 
  areas 
  of 
  Jurassic 
  

   rocks 
  which 
  cap 
  the 
  summits 
  of 
  the 
  mesas 
  between 
  Salt 
  Creek 
  and 
  the 
  

   creek 
  rising 
  about 
  stations 
  65 
  and 
  66. 
  They 
  are 
  remnants 
  of 
  strata 
  

   that 
  once, 
  in 
  all 
  probability, 
  extended 
  over 
  the 
  Salt 
  Mountains. 
  

  

  Between 
  Grand 
  Eiver, 
  the 
  Dolores, 
  and 
  the 
  creek 
  flowing 
  northeast 
  

   from 
  station 
  65 
  the 
  rocks 
  are 
  Triassic 
  on 
  the 
  surface, 
  with 
  Upper 
  Car- 
  

   boniferous 
  and 
  in 
  a 
  few 
  places 
  Middle 
  Carboniferous 
  showing 
  in 
  the 
  

   caiions. 
  A 
  line 
  of 
  hogbacks 
  dipping 
  toward 
  the 
  north 
  extends 
  from 
  

   Grand 
  Eiver, 
  8 
  miles 
  below 
  the 
  ]3olores, 
  to 
  a 
  point 
  on 
  the 
  latter 
  12 
  miles 
  

   above 
  its 
  mouth. 
  The 
  Grand 
  cuts 
  through 
  this 
  ridge 
  at 
  right 
  angles 
  to 
  

   its 
  trend. 
  The 
  caiion 
  of 
  Grand 
  Eiver 
  here 
  is 
  cut 
  almost 
  entirely 
  in 
  red 
  

   rocks, 
  and 
  as 
  we 
  follow 
  its 
  course 
  with 
  the 
  eye 
  from 
  the 
  summits 
  of 
  the 
  

   Salt 
  Mountains 
  we 
  can 
  see 
  huge 
  buttes 
  and 
  monument-like 
  masses 
  of 
  

   these 
  red 
  rocks 
  capped 
  with 
  remnants 
  of 
  the 
  layer 
  of 
  massive 
  red 
  sand- 
  

   stone. 
  A 
  view 
  to 
  the 
  northwest 
  from 
  the 
  mountains 
  showed 
  us 
  an 
  area 
  

   that 
  seemed 
  to 
  be 
  entirely 
  destitute 
  of 
  vegetation. 
  The 
  rocks 
  were 
  red 
  

   and 
  presented 
  rounded 
  forms 
  as 
  though 
  carved 
  into 
  rocJies 
  moutonnees 
  

   by 
  glacial 
  action, 
  it 
  is 
  probable 
  that 
  the 
  Sierra 
  la 
  Sal 
  was 
  once 
  the 
  

   seat 
  of 
  local 
  glaciers, 
  although 
  the 
  proof 
  of 
  their 
  former 
  existence 
  is 
  not 
  

   easily 
  demonstrated. 
  I 
  noticed 
  no 
  strise, 
  nor 
  could 
  I 
  be 
  positive 
  in 
  re- 
  

   gard 
  to 
  the 
  existence 
  of 
  moraiual 
  matter. 
  The 
  form 
  of 
  the 
  valleys 
  at 
  

   the 
  sources 
  of 
  the 
  streams 
  in 
  the 
  mountains 
  leads 
  us 
  to 
  suspect 
  their 
  

   former 
  existence. 
  The 
  great 
  elevation 
  of 
  the 
  mountains 
  above 
  the 
  

   country 
  surrounding 
  them 
  has 
  subjected 
  them 
  to 
  so 
  much 
  erosion 
  that 
  

   evidences 
  of 
  glacial 
  action 
  would 
  be 
  naturally 
  much 
  obscured. 
  As 
  to 
  the 
  

   age 
  of 
  the 
  mountains 
  all 
  that 
  can 
  be 
  said 
  is 
  that 
  their 
  elevation 
  took 
  

   place 
  in 
  Post-Cretaceous 
  time, 
  and 
  was 
  probably 
  contemporaneous 
  with 
  

   that 
  of 
  the 
  isolated 
  groups 
  of 
  the 
  Elk 
  Mountains 
  and 
  those 
  of 
  the 
  South- 
  

   west, 
  Abajo, 
  &G. 
  The 
  Sierra 
  la 
  Sal 
  will 
  be 
  referred 
  to 
  again 
  under 
  the 
  

   " 
  Eruptive 
  Eocks." 
  

  

  SINDBAD'S 
  VALLEY. 
  

  

  Sindbad's 
  Valley 
  is 
  the 
  curious, 
  kidney-shaped 
  basin 
  in 
  which 
  the 
  

   branches 
  of 
  Salt 
  Creek 
  rise. 
  Its 
  axis 
  has 
  a 
  direction 
  northwest 
  and 
  

   southeast. 
  It 
  has 
  but 
  one 
  outlet, 
  viz, 
  the 
  caiion 
  through 
  which 
  Salt 
  Creek 
  

  

  I 
  

  

  