﻿8. 
  Powers— 
  The 
  Butler 
  Salt 
  Dome. 
  131 
  

  

  tain, 
  between 
  Bine 
  Lake 
  and 
  the 
  Trinity 
  River, 
  is 
  still 
  

   higher. 
  Within 
  the 
  inner 
  circle 
  of 
  hills 
  the 
  top 
  of 
  the 
  

   dome 
  has 
  little 
  relief. 
  If 
  the 
  trne 
  elevation 
  of 
  the 
  

   Trinity 
  River 
  is 
  230 
  feet 
  the 
  assumed 
  datum 
  on 
  the 
  ac- 
  

   companying 
  map 
  is 
  about 
  20 
  feet 
  too 
  low. 
  The 
  elevation 
  

   of 
  the 
  divide 
  becomes 
  295 
  feet, 
  that 
  of 
  the 
  higher 
  hills 
  

   365 
  feet, 
  that 
  of 
  the 
  Llewellyn 
  gin 
  lake 
  315 
  feet. 
  

  

  Stream 
  adjustment 
  to 
  the 
  dome 
  is 
  also 
  shown 
  in 
  the 
  

   bend 
  of 
  the 
  Trinity 
  River 
  around 
  Rocky 
  Mountain. 
  The 
  

   river 
  at 
  one 
  time 
  probably 
  flowed 
  south 
  of 
  the 
  Mountain 
  

   and 
  at 
  that 
  time 
  formed 
  the 
  depression 
  occupied 
  by 
  Blue 
  

   Lake. 
  At 
  times 
  of 
  very 
  high 
  water 
  the 
  river 
  flows 
  into 
  

   the 
  prairies 
  on 
  either 
  side 
  of 
  the 
  saline. 
  

  

  Lakes 
  are 
  one 
  of 
  the 
  characteristic 
  features 
  of 
  the 
  

   interior 
  salt 
  domes. 
  The 
  Palestine, 
  Steen, 
  and 
  Grand 
  

   Saline 
  domes 
  have 
  central 
  lakes 
  surrounded 
  by 
  hills. 
  

   Brooks 
  and 
  Keechi 
  domes 
  have 
  saline 
  prairies, 
  but 
  no 
  

   lakes. 
  Butler 
  dome 
  has 
  the 
  Llewellyn 
  gin 
  lake 
  just 
  

   within 
  the 
  inner 
  circle 
  of 
  hills. 
  This 
  lake 
  is 
  intermittent 
  : 
  

   it 
  dries 
  up 
  in 
  dry 
  seasons 
  and 
  it 
  is 
  never 
  deeper 
  than 
  

   5 
  feet. 
  The 
  water 
  is 
  fresh 
  and 
  no 
  salt 
  incrustation 
  is 
  

   found 
  near 
  the 
  margin. 
  Formerly 
  the 
  area 
  now 
  occupied 
  

   by 
  the 
  lake 
  must 
  have 
  been 
  drained 
  either 
  to 
  the 
  north- 
  

   west 
  or 
  to 
  the 
  south, 
  probably 
  through 
  the 
  former 
  "wind 
  

   gap." 
  It 
  is 
  evident 
  that 
  the 
  depression 
  was 
  formed 
  by 
  

   solution 
  of 
  underlying 
  salt 
  probably 
  subsequent 
  to 
  the 
  

   latest 
  rejuvenation 
  of 
  the 
  streams 
  and 
  to 
  the 
  resultant 
  

   lowering 
  of 
  the 
  ground 
  water 
  level. 
  

  

  Springs. 
  

  

  Associated 
  with 
  all 
  interior 
  salt 
  domes 
  there 
  are 
  bar- 
  

   ren 
  prairies 
  partly 
  covered 
  with 
  salt-marsh 
  grass, 
  boggy 
  

   areas 
  into 
  which 
  one 
  may 
  sink 
  into 
  sand 
  or 
  blue 
  clay 
  

   to 
  an 
  untested 
  depth, 
  and 
  springs 
  of 
  very 
  slightly 
  min- 
  

   eralized 
  water. 
  Some 
  of 
  these 
  springs 
  are 
  sulphur 
  

   water, 
  some 
  "soda" 
  water, 
  some 
  "sour" 
  (alum) 
  water. 
  

   On 
  evaporation 
  "salt 
  licks" 
  result 
  and 
  salt 
  can 
  be 
  ex- 
  

   tracted 
  by 
  evaporating 
  the 
  white 
  residue 
  on 
  the 
  surface 
  

   of 
  the 
  ground. 
  During 
  the 
  Civil 
  War 
  salt 
  was 
  procured 
  

   from 
  several 
  of 
  the 
  interior 
  domes 
  including 
  Butler, 
  

   the 
  locality 
  being 
  near 
  Blue 
  Lake. 
  The 
  almost 
  tasteless 
  

   white 
  salt 
  which 
  is 
  common 
  as 
  a 
  thin 
  incrustation 
  on 
  

  

  