SOUTHWESTERN    NEVADA    AND    EASTERN    CALIFORNIA.  67 
Kawich. — Kawich  is  situated  in  a  detrital  embayment  on  the  east  side  of  the  Kawich 
Range.  The  town  is  54  miles  south  of  east  of  Goldfield.  The  district  is  known  as  the  Gold- 
eed  mining  district.  The  first  locations  were  made  in  December,  1904,  and  early  in  the 
pring  of  1905  several  hundred  men  rushed  to  the  camp.  When  visited  by  the  writer 
August,  1905)  there  were  about  ten  miners  at  work.  Considerable  development  work  has 
)een  done,  two  shafts  reaching  150  feet,  and  several  thousand  feet  of  drifts  have  been  driven. 
The  mines  are  situated  on  a  gently  sloping  area  of  wash,  from  which  numerous  small, 
•ugged  outcrops  of  monzonite-porphyry  and  smooth  ones  of  rhyolite  protrude.  The  mon- 
onite-porphyry  is  older  than  the  rhyolite  and  has  so  far  been  the  ore  bearer.  Fresh  speci- 
nens  of  the  former  are  gray  in  color,  with  many  rather  large  phenocrysts  of  feldspar  and 
dther  hornblende  or  biotite,  or  both. 
The  first  locations  were  made  on  the  property  of  the  Goldreed  Mining  Company.  Here  a 
•ugged  outcrop  of  intensely  silicified  monzonite-porphyry,  dark  brown  on  weathered  sur- 
aces,  contains  in  many  cavities  plates  of  hackly  gold,  some  of  which  are  an  inch  in  diameter. 
Numerous  other  areas  of  silicified  monzonite-porphyry  have  been  located  by  prospectors, 
>ut  at  none  was  gold  visible  to  the  eye,  although  many  panned  gold.  The  silicified  por- 
phyry is  light  grayish  brown  on  fresh  surfaces  and  breaks  with  a  conchoidal  fracture.  The 
boundary  between  the  silicified  and  unsilicified  portion  is  usually  sharp.  The  numerous 
cavities  are  due  to  the  removal  of  the  monzonite-porphyry  phenocrysts  prior  to  the  depo- 
sition of  native  gold.  Strong  iron  stains  and  some  dendrites  of  manganese  dioxide  are 
issociated  with  the  gold.  The  iron  stains  probably  point  to  pyrite  as  the  original  source  of 
:he  ore,  an  inference  strengthened  by  the  presence  of  gypsum.  Quartz  veinlets  cut  the 
silicified  monzonite-porphyry  but  are  said  to  carry  no  values.  Certain  clear  phenocryst-like 
quartz  areas  indicate  that  silicification  continued  after  the  removal  of  the  phenocrysts  usual 
in  the  porphyry.  The  deepest  shafts  show  that  the  silicified  porphyry  holds  its  width, 
although  up  to  the  time  of  this  examination  the  values  are  low  except  at  the  surface.  At 
the  Goldreed  mine  good  values  have  been  obtained  in  a  kaolinitic  substance  found  in  the 
cavities  of  the  silicified  monzonite-porphyry  at  the  100-foot  level.  Associated  with  the 
silicified  facies  are  white  kaolinized  facies,  which  are  often  stained  red  or  purplish  by  iron 
salts. 
Iron  pyrite  has  been  encountered  on  the  150-foot  level  at  the  Goldreed  mine  disseminated 
in  unsilicified  monzonite-porphyry.  Its  assay  value  is  low.  Several  thin  veins  of  pyrite 
occur  on  the  lower  levels  of  the  Diamond  No.  2.  These  veins  are  crustified,  and  vugs  some- 
times occur  in  the  center.     This  pyrite  is  said  to  assay  $35  in  gold  per  ton. 
The  silicified  porphyry  has  been  considerably  faulted  and  slickensides  and  breccias  are 
pommon.  At  the  Goldreed  mine  the  faulting  has  been  very  complex  and  certain  cavities 
appear  to  be  due  to  faulting.  These  cavities  are  wedge-shaped  and  reach  a  maximum 
ength  of  5  feet.  At  the  Chief  Kawich  the  faults  strike  N.  50°  W.,  parallel  to  the  silicified 
monzonite-porphyry  boundary,  and  dip  80°  SW.  At  the  Diamond  No.  2  the  faults  dip  45°  E. 
The  step-like  offsets  in  the  silicified  monzonite-porphyry  on  which  the  Chief  Kawich  and  the 
Goldreed  mines  are  situated  is  rather  suggestive  of  faulting,  although  the  effect  may  be 
due  to  a  chance  distribution  of  several  small  areas  of  silicified  porphyry. 
|  The  resemblance  between  the  Kawich  and  Gold  Crater  deposits  is  close.  It  is  probable 
that  waters  bearing  silica  in  solution  rose  along  joint  and  fault  planes  and  that  silica  more 
pr  less  completely  replaced  the  rock  contiguous  to  the  fractures.  Pyrite  was  probably 
/deposited  simultaneously,  partly  in  the  country  rock  and  partly  in  open  fissures.  Since 
the  silicification  the  veins  have  been  faulted.  The  kaolinization  of  certain  portions  of 
the  porphyry  was  probably  contemporaneous  with  the  surface  alteration  of  the  original 
sulphides.  From  the  lean  character  of  the  pyrite  so  far  encountered  it  is  probable  that 
the  rich  surface  gold  deposits  have  been  concentrated  from  the  pyrite  contained  in  many 
feet  of  monzonite-porphyry,  which  have  been  removed  by  erosion.  Other  rich  bodies  of 
pre  will,  however,  probably  be  encountered  above  the  level  of  ground  water,  which  is  here 
jdeep. 
