124  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1905. 
is  in  southern  Albany  County.  A  part  of  the  same  geographical  section  is  the  Pearl  district 
of  northern  Colorado.  Encampment,  Carbon  County,  has  the  only  large  smelter  in  Wyo- 
ming, and  an  aerial  tramway,  16  miles  in  length,  the  longest  in  the  West,  connects  the  smelter 
with  the  Ferris-Haggarty  mine.  The  smelter,  tramway,  mine,  and  other  property  of  the 
North  American  Copper  Company  were,  after  default  in  the  payment  of  interest  on  bonds 
and  a  foreclosure,  taken  over  by  its  successor,  the  Penn-Wyoming  Copper  Company. 
The  district  has  been  fully  described  by  Spencer, a  from  whose  paper  the  following 
synopsis  has  been  taken: 
The  region  is  one  of  quartzites  and  schists.  The  beds  have  a  prevailing  east-west  course 
and  dip  steeply  to  the  north  and  are  intruded  by  igneous  rocks.  The  ore  bodies  are  recon- 
centration  enrichments  along  channels,  due  to  the  netted  fracturing  of  the  rocks. 
The  ore  is  siliceous  and  needs  an  iron  flux,  gossan  for  this  purpose  being  mined  at  a 
locality  9  miles  away  and  hauled  to  the  smelter. 
The  smelter  is  at  the  town  of  Encampment.  The  ore  is  carried  by  rope  tramway  16 
miles  across  the  range,  over  two  divides  and  two  valleys.  Coal  is  supplied  from  a  locality 
8  miles  from  the  mines  and  hauled  up  grade  in  wagons  to  the  furnaces.  There  are  two 
producing  mines — the  FerrisrHaggarty  and  the  Doane. 
The  Doane-Rambler  mine  is  the  second  largest  of  the  Encampment  district.  The  shaft 
is  now  (1905)  600  feet  deep,  with  several  hundred  feet  of  drifts  cutting  through  both  low- 
grade  and  high-grade  ores.  The  property  is  equipped  with  a  complete  machinery  plant 
and  is  said  to  have  the  largest  ore  reserves  of  any  mine  in  the  district. 
The  Ferris-Haggarty  ore  body  lies  between  steeply  dipping  schists  and  quartzites,  the 
schists  lying  above  the  ore.  The  ore  consists  of  chalcocite  and  chalcopyrite  impregnating 
and  replacing  crushed  quartzite,  which  forms  the  gangue.  Much  of  the  ore  requires  con- 
centration. The  ore  body  is  250  to  300  feet  long,  and  varies  from  a  few  inches  in  thickness 
at  the  end  up  to  30  feet  in  the  middle.  The  schist  hanging  wall  is  very  regular;  the  foot 
wall  is  very  irregular,  being  governed  by  the  amount  of  brecciation  or  fracturing  of  the 
quartzite.     But  one  pipe  of  ore  has  as  yet  been  found. 
The  Doane  is  of  the  same  type.  The  ore  is  glance,  with  lesser  amounts  of  chalcopyrite, 
bornite,  and  rarely  of  covellite.  The  ore  body  is  an  elliptical  "pipe"  lying  in  a  bed  of 
quartzite,  dipping  steeply  to  the  north,  the  ore  shoot  having  a  wavy  pitch  to  the  west. 
a  Prof.  Paper  U.  S.  Geol.  Survey  No.  25,  1904. 
