bodtwell.]  VANADIUM    AND    URANIUM    IN    UTAH.  205 
of  this  region  (Sheet  XIV.  by  Holmes,  in  the  Hayden  Atlas)  gives 
the  area  included  in  the  Richardson  amphitheater  as  upper  Carbon- 
iferous, inclosed  by  and  dotted  with  inliers  of  red  beds  of  "Jura- 
Trias  "  age. 
The  stratigraphic  relation  between  the  sandstone  series  and  the 
underlying  conglomeratic  formation  is  significant.  If  no  unconform- 
ity exists  at  this  horizon  it  is  possible  that  the  conglomerate  forma- 
tion is  equivalent  to  Triassic  conglomerates  of  the  Dolores  formation 
in  western  Colorado.0  On  the  other  hand,  if  an  unconformity  does 
exist  here,  the  conglomerates  may  be  correlated  with  Carboniferous 
conglomerates  of  Colorado.  The  final  solution  of  this  important 
stratigraphic  problem  must  await  detailed  comparative  study,  prefer- 
ably by  geologists  familiar  with  the  Colorado  section. 
The  structure  of  this  series  partakes  of  the  general  north -north- 
west monoclinal  dip  of  the  region.  This  is  interrupted,  however,  by 
a  zone  of  deformation  which  enters  the  Richardson  amphitheater  at 
the  northeast,  near  the  month  of  Fisher  Creek,  crosses  in  a  south- 
westerly course,  indicated  by  breccias  and  steeply  upturned  beds,  and 
passes  out  on  the  southwest  along  a  zone  marked  by  intense  crumpling 
and  probable  faulting.  Crumpling,  fissnring,  and  faulting  on  a 
small  scale  are  common  throughout  this  zone.  No  igneous  rocks  were 
found  in  place,  although  some  are  reported  by  prospectors  to  occur 
about  10  miles  south,  on  Grand  River,  and  about  15  miles  southeast, 
in  the  foothills  of  the  La  Sal  Mountains. 
Character  of  the  ores. — The  deposits  are  chiefly  compounds  of 
vanadium,  including  vanadio-arsenates  of  copper,  barium,  and  cal- 
cium. These  and  perhaps  additional  compounds  of  vanadium  occur, 
in  all  instances  observed,  in  aggregates  of  small,  brittle,  green,  greenish- 
yellow,  and  yellowish-green  crystals.  Individual  crystals  are  about 
one-sixteenth  of  an  inch  in  diameter,  and  have  the  forms  of  thin, 
imperfectly  terminated  folia  or  plates.  They  are  grouped  parallel 
or  radiate  in  sheaves  or  wreaths.  The  light-olive  or  yellowTish-green 
varieties  are  distributed  irregularly,  while  the  darker  green,  roughly 
circular  crystals  are  usually  in  rosettes  or  wreaths.  The  olive  and 
yellowish  crystals  have  a  characteristically  pearly  luster,  and  the  deep 
green  ones  usually  show  a  dull,  waxy  luster.  Small  oval  masses  of 
amorphous  carnotite  and  also  small  yellow  crystals,  slightly  darker 
than  this  carnotite.  are  intimately  associated  with  the  green  crystals. 
The  exact  mineralogical  description  of  the  several  species  will  be 
reserved  for  the  final  paper.  From  his  preliminary  analyses.  Doctor 
Hillebrand  lias  decided  that  one  of  the  minerals  is  a  new  variety  of 
"Cross,  ('.  W..  Description  of  the  Telluride  quadrangle:  Geologic  Atlas  I  .  S..  folio  57, 
U.  S.  Geol.  Survey. 
