UTAH.  W£> 
gulches  three  lots  of  indicative  fossils  were  collected.  These  have 
been  determined  by  Dr.  G.  H.  Girty  to  belong  to  the  lower  Carboni- 
ferous (Mississippian).  Accordingly  it  would  appear  that  the  great 
sandstone  series  is  earlier  than  lower  Carboniferous. 
It  was  not  practicable  to  remain  in  this  region  long  enough  to  work 
out  the  detailed  structure,  nor  to  examine  the  character  of  the  contact 
between  the  lower  Carboniferous  and  the  underlying  siliceous  series. 
In  general,  it  was  noted  that  the  members  which  immediately  underlie 
the  fossiliferoiis  limestone  include  varicolored  and  cross-bedded  sand- 
stones and  quartzite,  black  fucoid  shales,  and  occasional  waterworn 
quartz  pebbles.  Special  investigation  of  these  problems  was  under- 
taken by  a  Survey  party  last  summer,  and  the  result  of  that  work  will 
throw  much  additional  light  on  this  important  geologic  problem. 
ECONOMIC  FEATURES. 
The  traditional  absence  of  deposits  of  metallic  ores  in  the  Uinta 
Range  and  the  prospective  development  of  this  region  in  the  near 
future  gave  added  interest  to  the  detection  of  such  deposits  during  the 
reconnaissance.  Reports  were  obtained  regarding  a  number  of  appar- 
ently unimportant  occurrences  within  the  limits  of  the  quadrangle. 
Copper  is  stated  to  have  been  found  in  a  narrow  seam  near  Rockport, 
in  the  riverbed  just  east  of  the  north  line  of  the  town.  In  1874 small 
seams  of  argentiferous  lead  ore  were  discovered  in  the  southwest  por- 
tion of  the  range,  on  Beaver  Creek,  2  to  3  miles  southeast  of  Kamas, 
and  iron  associated  with  some  lead  was  reported  in  the  fall  of  1902  in 
Hoyles  Canyon,  in  the  extreme  western  end  of  the  Uinta  Range. 
East  of  the  Coalville  quadrangle  iron  deposits  are  known  to  occur 
in  at  least  two  localities  in  the  Uinta  Mountains.  One  of  these  was 
recently  visited  by  Mr.  James  A.  Hogle,  a  mining  engineer,  of  Salt 
Lake  City,  Utah,  from  whom  the  following  information  was  obtained: 
The  deposit  is  located  in  the  northeast  shoulder  of  Utah,  in  Uinta 
County,  20  miles  north  of  Vernal,  and  8  to  9  miles  east  of  the  point 
at  which  Green  River  enters  Utah  in  Spring  Creek  Valley,  on  the 
boundary  between  Utah  and  Wyoming.  It  is  a  brown,  manganese- 
iron  ore  of  limonitic  character.  It  outcrops  prominently  as  a  bed  3 
to  8  feet  in  thickness  at  the  crest  of  a  hogback,  and  is  traceable  along 
its  strike  for  several  hundred  feet.  The  age  of  the  sandstone  country 
was  not  determined,  but  it  occupies  an  area  which  has  been  previously 
mapped  as  Jurassic  and  Cretaceous. ° 
This  deposit  has  been  visited  by  prospectors  and  representatives  of 
mining  exploration  companies,  who  report  traces  of  gold  in  the  iron 
and  a  siliceous  gangue.     It  is  their  opinion  that,  although  this  ore  is  of 
"White,  C.  A.,  Geology  and  geography  of  a  portion  of  northwest  Colorado  and  adjacent  parts  of 
Utah  and  Wyoming:  Ninth  Ann.  Kept.  U.  S.  Geol.  Survey,  1889,  pi.  lxxxviii. 
Bull.  225—04 15 
