﻿1±*2 
  S. 
  Powers 
  — 
  The 
  Butler 
  Salt 
  Dome. 
  

  

  Cambrian 
  area 
  is 
  interpreted 
  as 
  the 
  western 
  edge 
  of 
  an 
  

   extensive 
  Pennsylvanian 
  land 
  mass 
  and 
  as 
  the 
  old 
  shore 
  

   line. 
  It 
  is 
  not 
  believed 
  to 
  be 
  a 
  narrow 
  land 
  area, 
  or 
  

   horst, 
  along 
  the 
  Balcones 
  fault 
  line. 
  

  

  Further 
  information 
  concerning 
  the 
  extent 
  of 
  this 
  

   former 
  land 
  area, 
  which 
  is 
  of 
  much 
  greater 
  magnitude 
  and 
  

   importance 
  than 
  the 
  buried 
  granite 
  ridge 
  in 
  Kansas, 
  is 
  

   being 
  secured 
  by 
  the 
  subsurface 
  discoveries 
  at 
  Healdton, 
  

   Oklahoma, 
  and 
  at 
  Electra, 
  Burkburnett, 
  and 
  Petrolia, 
  

   Texas, 
  and 
  in 
  the 
  area 
  south 
  and 
  east 
  of 
  these 
  fields. 
  15 
  

   Granite 
  of 
  pre-Cambrian 
  age 
  has 
  been 
  found 
  beneath 
  the 
  

   Petrolia 
  field, 
  in 
  Clay 
  County, 
  at 
  a 
  depth 
  of 
  4,240 
  feet 
  in 
  

   the 
  Texas 
  Company 
  Byers 
  No. 
  41 
  and 
  in 
  a 
  well 
  7 
  miles 
  

   north 
  of 
  St. 
  Jo, 
  Montague 
  County, 
  at 
  3,007 
  feet. 
  Lime- 
  

   stone, 
  which 
  has 
  been 
  identified 
  as 
  probably 
  of 
  Ordovi- 
  

   cian 
  age, 
  occurs 
  above 
  the 
  granite 
  in 
  the 
  Byers 
  well 
  below 
  

   3,750 
  feet 
  and 
  in 
  Ball 
  No. 
  1, 
  5 
  miles 
  north 
  of 
  Myra, 
  Cooke 
  

   County, 
  below 
  2,195 
  feet 
  (identified 
  by 
  Dr. 
  J. 
  A. 
  Udden). 
  

   However, 
  most 
  of 
  the 
  massive 
  limestone 
  found 
  in 
  the 
  

   deep 
  wells 
  in 
  the 
  Red 
  River 
  section 
  is 
  supposed 
  to 
  be 
  of 
  

   Pennsylvanian 
  age, 
  unconformable 
  with 
  the 
  overlying 
  

   Cisco 
  beds. 
  These 
  buried 
  hills 
  are 
  interpreted 
  as 
  out- 
  

   liers 
  of 
  the 
  main 
  land 
  area 
  to 
  the 
  southeast. 
  

  

  A 
  very 
  plausible 
  Cretaceous 
  age 
  for 
  the 
  hypothetical 
  

   salt 
  body 
  which 
  furnished 
  the 
  interior 
  domes 
  — 
  basal 
  Cre- 
  

   taceous 
  or 
  basal 
  Upper 
  Cretaceous 
  — 
  and 
  a 
  basal 
  Tertiary 
  

   age 
  for 
  the 
  salt 
  body 
  which 
  furnished 
  the 
  coastal 
  domes 
  

   has 
  been 
  suggested 
  by 
  Dumble. 
  16 
  

  

  The 
  conditions 
  necessary 
  for 
  the 
  formation 
  of 
  salt 
  

   domes 
  appear 
  to 
  be; 
  first, 
  a 
  bed 
  of 
  salt 
  of 
  considerable 
  

   thickness 
  and 
  of 
  sedimentary 
  origin; 
  second, 
  a 
  synclinal 
  

   area 
  causing 
  deep 
  burial 
  of 
  the 
  salt 
  bed; 
  and 
  third, 
  a 
  

   system 
  of 
  lines 
  of 
  weakness 
  comparable 
  to 
  a 
  system 
  of 
  

   joint 
  planes 
  along 
  which 
  there 
  is 
  no 
  actual 
  displacement, 
  

   but 
  at 
  the 
  junction 
  of 
  which 
  the 
  salt 
  may 
  break 
  through. 
  

  

  :5 
  The 
  Ordovician 
  Healdton 
  Hills 
  have 
  been 
  described 
  by 
  the 
  writer, 
  but 
  

   a 
  question 
  has 
  arisen 
  as 
  to 
  whether 
  the 
  Pennsylvanian 
  section 
  belongs 
  to 
  the 
  

   Glenn 
  formation 
  or 
  to 
  a 
  formation 
  extending 
  northward 
  from 
  Texas 
  which 
  

   is 
  covered 
  by 
  progressive 
  overlap 
  (an 
  unpublished 
  opinion 
  by 
  Mr. 
  Ben 
  Belt, 
  

   of 
  Fort 
  Worth, 
  Texas) 
  . 
  

  

  Buried 
  limestone 
  hills 
  at 
  Petrolia 
  were 
  first 
  discovered 
  by 
  Mr. 
  W. 
  E. 
  

   Wrather, 
  of 
  Dallas, 
  Texas, 
  but 
  recent 
  developments 
  have 
  just 
  been 
  published 
  

   by 
  Lee 
  Hager 
  (Eed 
  Eiver 
  uplift 
  has 
  another 
  angle, 
  Oil 
  and 
  Gas 
  Journal, 
  

   Oct. 
  17, 
  1919, 
  pp. 
  64-5). 
  

  

  16 
  E. 
  T. 
  Dumble, 
  op. 
  cit. 
  

  

  