174  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1903.  [bull.  225. 
of  promise.  The  Shasta  King  ore  body  lies  upon  the  west  slope  of 
the  South  Fork  of  Squaw  Creek  nearly  opposite  and  at  a  lower  level 
than  Windy  Camp.  As  the  general  dip  of  the  Windy  Camp  body 
is  toward  the  Shasta  King  they  have  been  regarded  as  belonging  to 
the  same  shear  zone.  This  view  is  strengthened  by  the  occurrence  of 
smaller  ore  bodies  on  the  steep  slope  between  them  which  suggests 
that  a  former  connection  has  been  severed  by  the  erosion  of  Squaw 
Creek.  The  relations  are  not  yet  clearly  understood  and  can  not  be 
fully  worked  out  until  the  deeper  parts  of  the  WTindy  Camp  bod}^  are 
disclosed  in  detail. 
The  Shasta  King  ore  body  is  somewhat  irregularly  basin  shaped,  is 
some  hundreds  of  feet  in  width,  and  has  a  longer  nearly  north-south 
axis  rising  to  the  north  and  limited  for  the  most  part  by  fissures  along 
which  there  has  been  decided  shearing.  An  exception  is  found  in 
places  on  the  upper  surface  of  the  ore  body  where  it  is  solidly  "frozen" 
to  the  country  rock.  The  region  is  one  of  much  disturbance  and  the 
bodies  of  copper  ore  appear  to  have  suffered  greater  deformation  than 
the  adjacent  quartz  veins. 
Mammoth  lode. — Exploration  has  continued  upon  the  Mammoth 
lode  under  the  superintendence  of  Mr.  Fred.  Grotefend.  Its  general 
course  appears  to  be  about  N.  80°  E.  It  has  been  traced  over  300 
feet  in  length  to  a  depth  of  at  least  200  feet  from  the  upper  gossan 
cropping.  On  the  principal  level  it  dips  30°  NW.  and  crosscut  tun- 
nels show  an  extensive  development  in  that  direction  which  may  be 
accounted  for,  in  part  at  least,  by  change  to  gentler  dip.  The  ore,  like 
that  of  all  the  ore  bodies,  is  composed  chiefly  of  pyrite  but  is  locally 
rich  in  chalcopyrite  and  considerable  sphalerite.  Quartz  is  the  gangue 
mineral,  but  in  much  of  the  ore  there  is  scarcely  a  trace  of  it. 
Beyond  Squaw  Creek  the  Friday  and  Lowden  prospect  has  not  been 
worked  to  any  considerable  extent  during  the  year.  The  Golinsky 
was  bonded  and  thoroughly  examined  by  the  Trinity  Copper  Com- 
pany. The  most  northern  openings  of  the  Iron  Mountain  district  are 
near  the  head  of  Little  Backbone  Creek,  where  the  Summit  mine  tun- 
nels completed  this  year  show  much  impregnated  metarhyolite  with 
included  slate  and  small  indistinctly  banded  veins  in  which  chalcopy- 
rite is  most  prominent,  with  smaller  amounts  of  quartz  and  pyrite. 
BULLY   HILL    DISTRICT. 
The  Bully  Hill  district  yields  more  than  any  other  district  wholly 
within  the  Redding  quadrangle.  It  has  two  ore-bearing  tracts,  one 
in  Bully  Hill  and  the  other  near  Copper  City,  besides  a  number  of 
prospects  to  the  west  on  the  slopes  of  Horse  Mountain.  All  these 
have  been  worked  more  or  less  continuously  during  the  year.  As  is 
now  generally  known  the  ores  of  the  Bully  Hill  district  differ  from 
those  of  the  district  west  of  the  Sacramento  in  containing  the  richer 
