62  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1905. 
$500  per  ton  in  gold  and  silver  values.  Such  assay  returns,  however,  in  at  least  the  majority 
of  cases,  were  obtained  from  picked  samples  and  are  of  no  value  in  estimating  the  economic 
importance  of  a  prospect. 
The  water  level,  to  judge  from  the  development  work  so  far  carried  on  in  the  Lida  dis- 
trict, is  comparatively  near  the  surface.  Much  of  the  ore  which  has  already  been  taken 
out  is  refractory  and  would  require  milling  and  smelting.  While  in  comparison  with  the 
surrounding  districts  the  Lida  district  is,  in  these  respects,  at  a  disadvantage,  there  is  a 
fair  growth  of  pifton  and  juniper  on  the  hills  surrounding  the  mines  which  will  furnish,  for 
a  time  at  least,  satisfactory  fuel  and  some  mining  timber.  Water  sufficient  for  mining 
and  domestic  purposes  flows  from  springs  in  and  above  the  village  and  can  be  obtained  in 
the  Lida  Valley  at  slight  depths. 
Lime  Point. — The  name  Lime  Point  is  applied  to  a  ridge  running  northwest  from 
Slate  Ridge.  Recently  a  number  of  claims  have  been  located  on  it  and  some  develop- 
ment work  is  now  being  done.  The  ridge  is  formed  of  a  coarse  biotite  granite  and  Cam- 
brian sedimentary  rocks.  The  intrusion  of  the  granite  has  strongly  metamorphosed  the 
limestone  and  the  shales  have  become  semischists.  The  granite  itself  is  cut  by  diorite- 
porphvry  dikes  and  by  pegmatite  and  aplitic  dikes.  Later  flows  of  basaltic  rocks  occupy 
small  areas. 
The  Bullfrog-George  mine  is  situated  on  the  side  of  a  rounded,  boss-like,  granite  hill, 
near  theLida-Old  Camp  road.  The  surrounding  hills  are  cut  by  quartz  veins  which  weather 
in  relief  and  can  be  traced  long  distances.  Some  of  these  contain  feldspar  and  others  can 
be  traced  into  pegmatite  dikes.  The  Bullfrog-George  development  work  is  being  done  on 
a  quartz  vein  from  4  to  '.»  feet  w  ide  which  is  traceable  about  a  quarter  of  a  mile.  The  vein 
is  vertical  and  strikes  \.  70°  \Y. 
The  vein  at  some  places  passes  gradually  into  the  granite,  the  white,  translucent  quartz 
of  the  granite  grading  into  that  of  the  \ein  without  break.  Again,  the  granite  appears  to 
have  been  shattered  prior  to  the  deposition  of  the  quartz,  which  now-  fills  linked  cavities 
in  the  granite.  The  quartz  vein  souk  times  sends  branches  into  the  granite.  Apparently 
isolated  in  the  quail/,  are  small  areas  of  pyrite  and  chalcopyrite,  with  less  galena  and 
chalcocite  or  a  related  sulphide.  The  quartz  in  many  portions  is  intensely  crushed,  this 
crushing  perhaps  being  contemporaneous  with  the  faults  which  cut  the  diorite-porphyry 
dikes.  The  crushed  fragments  have  been  recemented  by  limonite  or  a  chalcedonic  quartz 
much  stained  by  limonite.  With  these  knife-edges  of  limonite  and  in  limonite-stained 
cavities  malachite,  cerussite,  and  traces  of  azurite  occur.  Such  quartz  pans  free  gold, 
and  coarse  pannings  were  examined  from  the  intensely  iron-stained  contact  of  the  granite 
and  quartz.  The  feldspars  of  the  granite  within  4  feet  of  the  vein  arc  often  much  kaolin- 
ized.  At  the  east  end  of  the  quartz  veins  Jess  shattering  was  noted.  Vugs  lined  with 
quartz  crystals  are  common.  Other  vugs  are  lined  with  cubes  of  purple  fluorite  one-fourth 
inch  in  diameter,  while  finely  divided  flakes  of  molybdenite  are  sporadically  present  in  the 
quartz. 
The  quartz  vein  itself  appears  to  be  of  pegmatitic  origin  and  to  have  been  deposited 
while  portions  of  the  granite  were  still  viscous  and  other  portions  were  comparatively 
solid.  Later  faulting  occurred  and  the  quartz  vein  was  crushed.  Since  then  limonite 
and  chalcedonic  quartz  have  recemented  the  quartz  fragments.  The  period  at  which  the 
sulphide  mineralization  occurred  is  unknown.  The  molybdenite  and  fluorite  are  probably 
of  pegmatitic  origin,  while  the  sulphides  were  very  likely  formed  later. 
Water  is  at  present  hauled  from  a  pipe  line  on  the  Lida-Old  Camp  road  9  miles  distant, 
while  the  nearest  fuel  is  found  in  the  vicinity  of  Old  Camp.  The  camp  is  30  miles  from 
the  railroad  terminus  at  Goldfield. 
Tokop. — Tokop,  in  an  air  line,  is  4  miles  northeast  of  Old  Camp  and  25  miles  by  road 
west  of  south  of  Goldfield.  Rugged  hills  and  rounded  domes  rise  from  the  much-dissected 
mesa  lying  to  the  east  and  northeast  of  the  settlement.  The  rocks  present  are  those  already 
mentioned  as  occurring  at  Lime  Point,  with  the  addition  of  dikes  of  granite-porphyry 
which,  to  the  north  of  the  village,  cut  the  Cambrian  and  are  probably  to  be  correlated 
