CABNOTITE    IN     RIO    BLANCO    COUNTY,  COLO.  113 
proper  designation  of  these  lower  formations.     The  rock  strata,  how- 
ever, form  a  -cries  fairly  comparable  with  the  formations  known  easl 
f  the  Rocky  Mountain  ranges,  and  it    is  od   the  basis  of  similarity  <>f 
haracter  of  the  rocks  themselves  that  the  geologic  names  are  given. 
Below  the  gap  in  the  Dakota  ledges  Coal  Creek  emerges  into  an  open 
valley,  from  which,  after  making  a  short  turn  toward  the  north,  it 
Mice  more  turns  westward  and  cuts  into  the  sandstone  hogbacks 
he  coal  held.     Half  a  mile  or  so  beyond,  it  turns  to  the  south  toward 
iVhite  Hirer.     The  valley  between  the  coal-field  hogbacks  and  the 
Dakota  hogback  is  about  1|  miles  wide  and  is  eroded  on  a  formation 
if  comparatively  weaker  shales.      It  i-  divided  about  midway  by  a 
minor  hogback  ridge  due  to  the  presence  of  some  harder  sandy  layers. 
'he  total  thickness  of  these  shaly  strata  is  considerably  over  a  mile, 
ust  above  the  Dakota  ledge-  tin-  -hale  is  very  black,  dense,  and  in 
nany  places  slaty,  and  in  this  position  on  the  north  slope  ^(  Sleepy 
'at  Mountain  a  number  of  fossils  were  found  that  are  known  to  be 
f  Benton  age.     The  geologists  of  the  Hayden  survey  mapped  this 
vhole  predominatingly  shaly  formation   -except  a  few  hundred  feet 
t  the  top  that  were  placed  with  the  Fox  Hills  formati<  n    a-  the  Colo- 
ado  shale.     As  a  single  unit   the1  vhole  group  of  strata  above  the 
Dakota   sandstone   and   below   the  coal-bearing  formation  has  been 
ailed  the  Mancos  -hale  in  the  report  on  the  Yampa  coal  field. ' 
Above  the  Mancos  shale  the  coal-bearing  sandstones  and  shales 
Lttain  a  thickness  of  something  over  a  mile,  and  in  other  parts  of  the 
ield  these  rocks  arc  succeeded  and  overlain  by  still  later  formation.-. 
The  lumber  camp  known  as  "The  Transfer'3  is  in  the  rocky  gorge 
mere  Coal  Creek  enter-  the  lowermost  Ledges  of  the  coal-bearing  beds. 
Ul  of  thes<  rocks,  occupying  the  interval  from  the  beds  below  the 
Dakota  ledges  up  to  the  sandstone  ledges  near  "The  Transfer."  dip 
westward  at  rather  high  angles,  varying  from  about  55°  to  7o°.  (See 
ross  section,  PI.  III. 
PROSPECTS. 
CAYWool)    CLAIMS. 
A  number  of  claim-  on  which  only  prospect  pits  had  been  dug  were 
isited  in  company  with  Mr.  Gilbert  Wesson,  of  Meeker.  The  best 
bowing  of  carnotite  was  in  a  shallow  pit.  said  to  be  known  as  the 
'aywood  Xo.  1  claim.  This  is  situated  on  the  ridge  summit  at  an 
levation  of  1,100  feet  above  Coal  Creek,  about  half  a  mile  north  of 
he  point  where  the  creek  flows  through  the  Dakota  sandstone  ledg 
q  this  and  some  other  pits  near  by  there  was  an  apparent  abundance 
f  fossil  wood.  (Mated  with  bright-yellow  pigment.  This  coating  is 
ery  conspicuous  and  contrasts  markedly  with  the  dark  iron-brown 
Sfo.  297    1906. 
