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  R. 
  T. 
  Hill 
  — 
  Reconnaissance 
  of 
  the 
  

  

  of 
  the 
  Delaware 
  Mountains 
  near 
  the 
  Hudson 
  River 
  limestone. 
  

   The 
  Delaware 
  Mountains 
  proper 
  are 
  a 
  few 
  long 
  limestone 
  

   ridges 
  and 
  detached 
  buttes 
  in 
  the 
  beautiful 
  valley 
  of 
  Delaware 
  

   Creek. 
  Seven 
  miles 
  west 
  of 
  the 
  academy, 
  near 
  Bill 
  Jackson's, 
  

   they 
  are 
  composed 
  of 
  limestone 
  underlaid 
  by 
  the 
  above 
  men- 
  

   tioned 
  Favosites 
  sandstone 
  — 
  a 
  porous 
  gray 
  quartzite 
  with 
  an 
  

   occasional 
  patch 
  of 
  limestone. 
  The 
  buttes 
  are 
  peculiarly 
  dis 
  

   torted, 
  their 
  strata 
  being 
  disturbed 
  at 
  a 
  very 
  slight 
  angle 
  in 
  

   many 
  directions, 
  which 
  may 
  be 
  compared 
  to 
  the 
  uneven 
  curva- 
  

   ture 
  of 
  a 
  saddle. 
  

  

  The 
  Delaware 
  mountains 
  were 
  mentioned 
  by 
  Mr. 
  Jules 
  

   Marcou, 
  who 
  followed 
  the 
  old 
  Fort 
  Smith 
  and 
  Fort 
  Washita 
  

   trail 
  which 
  passed 
  by 
  them. 
  He 
  referred 
  them 
  to 
  the 
  Sub- 
  

   Carboniferous 
  or 
  Mountain 
  Limestone.* 
  The 
  scenery 
  in 
  the 
  

   Valley 
  of 
  the 
  Delaware 
  is 
  exquisite, 
  the 
  contrast 
  between 
  the 
  

   low 
  rounded 
  hills 
  and 
  the 
  extensive 
  valleys 
  with 
  their 
  peculiar 
  

   buttes 
  present 
  a 
  restful 
  and 
  varied 
  landscape. 
  The 
  region 
  

   promises 
  rich 
  scientific 
  treasures 
  to 
  some 
  future 
  student 
  who 
  

   has 
  time 
  and 
  facilities 
  to 
  work 
  out 
  its 
  structure 
  and 
  history. 
  

   It 
  was 
  impossible 
  to 
  trace 
  the 
  relation 
  of 
  the 
  Wapenucka 
  dis- 
  

   trict 
  to 
  the 
  Arbuckle 
  Mountains 
  to 
  the 
  westward, 
  owing 
  to 
  

   dangers 
  of 
  exploration 
  in 
  a 
  country 
  where 
  geologists 
  are 
  not 
  

   welcome, 
  but 
  there 
  is 
  evidently 
  a 
  close 
  connection 
  if 
  not 
  con- 
  

   tinuity 
  between 
  them. 
  * 
  

  

  2b. 
  The 
  Tishomingo 
  Granite. 
  — 
  In 
  the 
  heart 
  of 
  the 
  Chick- 
  

   asaw 
  nation 
  south 
  of 
  and 
  underlying 
  the 
  Wapenucka 
  limestone 
  

   district 
  is 
  an 
  extensive 
  granite 
  area. 
  This 
  is 
  the 
  central 
  divis- 
  

   ion 
  of 
  our 
  mountain 
  region. 
  It 
  is 
  a 
  triangular 
  area 
  of 
  sandy 
  

   prairie 
  land 
  with 
  low 
  rounded 
  granite 
  hills 
  and 
  undulations, 
  

   lying 
  between 
  the 
  Santa 
  Fe 
  and 
  M. 
  K. 
  and 
  T. 
  railroad 
  and 
  

   running 
  east 
  and 
  west 
  from 
  Boggy 
  depot 
  to 
  six 
  miles 
  west 
  of 
  

   Tishomingo, 
  and 
  northeast 
  to 
  Mill 
  Creek 
  and 
  beyond. 
  

  

  The 
  granite 
  is 
  well 
  displayed 
  two 
  miles 
  southwest 
  of 
  Boggy 
  

   station 
  ; 
  in 
  Pennington 
  Creek 
  ; 
  at 
  Tishomingo 
  and 
  other 
  places. 
  

   At 
  its 
  eastern 
  outcrop 
  it 
  is 
  composed 
  of 
  red 
  feldspar, 
  white 
  and 
  

   black 
  mica, 
  quartz 
  and 
  hornblende 
  with 
  numerous 
  pegmatitic 
  

   veins. 
  Its 
  composition 
  and 
  occurrence 
  is 
  nearly 
  identical 
  with 
  

   the 
  Burnet 
  Texas 
  granite, 
  and 
  it 
  is 
  unlike 
  the 
  igneous 
  rocks 
  of 
  

   the 
  Wichitas 
  to 
  be 
  described 
  later. 
  In 
  the 
  western 
  part 
  of 
  this 
  

   area 
  the 
  feldspar 
  is 
  albite. 
  There 
  are 
  numerous 
  dikes 
  of 
  

   black 
  rock 
  intersecting 
  this 
  granite 
  specimens 
  of 
  which 
  from 
  

   Pennington 
  Creek 
  have 
  been 
  sent 
  to 
  Professor 
  J. 
  F. 
  Kemp 
  for 
  

   study. 
  Concerning 
  these 
  he 
  says 
  : 
  *' 
  They 
  are 
  a 
  typical 
  dia- 
  

   base. 
  They 
  are 
  mostly 
  idiomorphic 
  plagioclase 
  crystals, 
  doubt- 
  

   less 
  labradorite 
  from 
  the 
  extinction 
  angles, 
  irregular 
  greenish 
  

   augite 
  and 
  a 
  little 
  magnetite. 
  They 
  show 
  the 
  so-called 
  ophitic 
  

  

  * 
  Geology 
  of 
  North 
  America. 
  

  

  