300  CONTRIBUTIONS    TO   ECONOMIC    GEOLOGY,  1904.        [bull.  260. 
to  300  feet  vertically  above  the  other.  These  veins  have  a  general 
northeast  strike,  and  dip  northwest  at  angles  of  18°  to  20°.  The 
reins  are  of  the  same  general  character  as  those  of  the  Golden  Che sj 
mine,  but  contain  rather  less  abundant  sulphides.  These  were  form- 
erly worked  by  the  Mother  Lode,  Occident,  and  Treasure  Box  mines 
by  flat  slopes  extending  from  the  surface  into  the  hill.  Some  pock- 
ets of  rich  ore,  containing  much  free  gold,  have  been  found  in  these. 
mines  and  were  treated  in  arrastras.  The  veins  as  a  whole,  however] 
are  of  rather  low  grade  and  have  not  been  sloped  for  more  than  a 
few  hundred  feet  from  the  surface.  Their  average  width  is  probably 
not  over  8  inches.  Just  west  of  these  veins  is  the  Mead  vein  which 
strikes  about  north  15°  east  and  dips  easterly  at  about  75°.  This 
is  a  fissure  vein,  cutting  the  beds  of  the  Prichard  formation.  Its 
relation  to  the  bed  veins  east  of  it  is  unknown,  as  it  apparently  has  not 
been  considered  worth  while  to  explore  the  intersections  or  junction! 
of  these  veins.  The  Mead  vein  is  said  to  contain  a  pay  shoot  of  $2a 
ore.  The  vein  consists  of  white  quartz  with  sometimes  a  little  side-rite 
(or  other  ferruginous  carbonate)  near  the  walls  and  with  auriferous 
pyrite,  chalcopyrite,  and  galena  in  the  medial  portion.  A  nurnbel 
of  small  bed  veins  have  been  worked  west  of  Murray,  the  most  noted 
being  the  nearly  horizontal  Buckeye  Boy,  in  Dream  Gulch,  which! 
produced  about  $25,000  in  gold  from  a  single  small  pocket. 
Placers. — The  older  placer  deposits  of  Murray  constitute  what  is 
locally  called  the  Old  Wash  and  are  remnants  of  an  earlier  channel 
of  Prichard  Creek  from  250  to  300  feet  above  the  present  stream] 
These  gravels,  which  are  in  part  derived  from  older  gravels  depositee! 
still  higher  above  the  present  valleys,  have  been  hydraulicked  near] 
Murray,  but  have  not  proved  A^ery  rich. 
Most  of  the  placer  gold  of  the  Murray  region  has  come  from  thd 
bottoms  of  the  existing  gulches  and  has  been  obtained  by  simple 
sluicing,  booming,  drifting,  and  dredging.  The  bed  of  Prichard  | 
Creek  has  been  worked  about  a  mile  west  of  Murray  by  a  hydraulic 
elevator,  but  the  depth  of  the  gravel,  which  averages  about  30  feet, 
has  proved  in  most  cases  an  insurmountable  obstacle  to  successful 
exploitation.  In  1903  three  dredges  were  at  work  near  Delta,  of 
which  one  only,  at  the  mouth  of  Trail  Creek,  was  operated  at  a  profit, 
on  gravel  running  about  10  cents  to  the  yard. 
The  gravel  of  Trail  Creek  near  Delta  is  from  18  to  20  feet  deep, 
and  was  formerly  worked  by  sinking  shafts  to  bed  rock  and  then 
drifting.  At  present  about  $6,000  a  year  is  obtained  from  these 
gravels  by  booming.  In  this  method  the  water  is  impounded  in  a 
reservoir  fitted  with  an  automatic  discharge  gate.  When  the  reser- 
voir is  full  the  gate  opens,  and  the  whole  body  of  Water  is  directel 
against  the  gravel  in  such  a  manner  as  to  wash  it  away.     A  small 
