diller]  REDDING   QUADRANGLE,  CALIFORNIA.  171 
town,  hear  the  southwest  corner  of  the  quadrangle.  The  gravels  of 
the  Horsetown  region  in  the  early  days  were  very  rich,  and  successful 
dredging,  under  good  management,  may  well  have  been  predicted  for 
that  region.  Hard  gravel  was  encountered,  and  early  in  the  season 
the  dredger  burned.  It  is  said  that  a  stronger  dredger,  of  greater 
capacity,  is  to  be  put  in  its  place,  and  is,  in  fact,  in  October,  1903, 
reported  well  under  wa}^ 
GOLD    OF   QUARTZ   MINES. 
The  demand  for  silica  to  flux  the  copper  ores  creates  a  favorable 
opportunity  for  mining  the  comparatively  low-grade  quartz  veins  of 
the  region,  and  during  1903  ore  was  sent  to  Keswick,  or  elsewhere, 
from  a  number  of  mines  within  the  quadrangle,  but  the  total  ship- 
ment in  part,  at  least,  of  carefully  selected  and  graded  ores  did  not 
amount  to  over  500  tons  per  month. 
The  country  rock  of  the  auriferous  quartz  veins  throughout,  with 
the  exception  of  the  Shasta  region  where  granodiorite  prevails,  is  essen- 
tially the  same  as  that  of  the  copper  ore  bodies  and  consists  of  an 
ancient  series  of  igneous  rocks,  andesites,  and  rlvyolites,  so  altered  by 
pressure  in  many  cases  as  to  closely  resemble  slate.  Most  of  the 
mines  are  shallow,  but  at  Old  Diggings,  G  miles  northwest  of  Red- 
ding, the  shafts  have  reached  a  depth  of  500  feet,  and  indicate  that  the 
ore  has  a  considerable  degree  of  continuity. 
Most  of  the  mines  about  Old  Diggings,  especially  the  Central, 
Evening  Star,  Mammoth,  and  Spanish,  were  working  to  a  greater  or 
less  extent  in  1903.  All  are  upon  somewhat  irregular  but  nearly  par- 
allel quartz  veins  which  have  a  general  course  a  few  degrees  east  of 
north  and  a  dip  of  about  85°  SE.  In  thickness  the  veins  range  from 
a  few  inches  to  18  feet,  and  carry  small  amounts  of  disseminated 
pyrite  and  chaicopyrite.  The  Central  mine  is  at  present  the  largest 
producer  of  the  Old  Diggings  vicinity,  and  furnishes  the  bucket  tram- 
way over  which  the  other  mines  of  that  place  ship  their  ores  across 
Sacramento  River  to  the  Southern  Pacific  Railroad. 
The  small  group  of  mines  near  Quartz  Hill,  1  miles  northwest  of 
Redding,  were,  at  the  time  of  my  visit,  less  active  than  in  1902,  but 
to  the  west,  near  the  old  Spanish  mine,  there  was  increased  activity 
at  the  Bracket  and  Crown  Deep.  The  quartz  veins  of  the  last  two 
mines  are  less  regular  than  those  east  of  the  Sacramento.  They  gen- 
erally strike  N.  12°  to  10°  W.,  and  are  crushed,  containing  vein 
material  of  various  ages. 
One  of  the  oldest  and  once  most  active  quartz  mines  of  the  Redding 
quadrangle  is  the  Uncle  Sam,  on  Squaw  Creek,  6  miles  west  of  Ken- 
nett.  Its  proximity  to  the  large  bodies  of  low-grade  copper  ore  makes 
it  of  special  interest,  and  the  Trinity  Copper  Company,  under  bond, 
has  recently  made  a  thorough  examination   of  the   property.     The 
