SOUTHWESTERN    NEVADA    AND    EASTERN    CALIFORNIA.  63 
with  similar  dikes  observed  at  Lida.  Rhyolite  flows  also  form  a  considerable  proportion 
of  the  mesa  already  mentioned.  The  Cambrian  shales  and  limestones  have  been  pro- 
foundly metamorphosed  and  near  the  granite  are  schists  and  garnet-quartz-epidote  rocks. 
They  are  complexly  folded  and  at  places  faulted.  The  granite  is  pink  and  coarse  grained. 
From  the  presence  of  granite  dikes  in  the  sedimentaries  and  from  certain  mining  data  it 
is  assumed  that  the  contact  of  the  granite  and  limestones  has  a  very  gentle  dip  and  that 
deep  mines  in  limestone  near  the  contact  will  probably  encounter  granite. 
The  properties  of  the  Gold  Crest  Mining  Company,  situated  three-fourths  of  a  mile  south 
of  Tokop,  were  examined  in  some  detail.  On  the  Ouida  claim  a  vertical  vein  cuts  the 
garnet-quartz-epidote  rock,  which  strikes  N.  10°  E.  and  dips  20°  W.  This  vein  is  1^  feet 
wide  and  strikes  N.  80°  W.  The  quartz  is  white  and  semitransparent.  The  quartz  of  the 
vein  lias  been  intensely  crushed  and  the  fragments  have  been  cemented  by  hematite  and 
limonite.  Dendrites  of  manganese  oxide  also  occur.  Some  portions  of  the  quartz  are  com- 
pact, with  here  and  there  an  iron-pyrite  cube  unaltered,  while  other  portions  have  a  few 
vugs  lined  with  quartz  crystals  or  are  honeycombed  with  iron-pyrite  casts.  From  the 
fact  that  the  compact  varieties  are  refractory  and  the  honeycombed  varieties  are  free  mill- 
ing, it  is  evident  that  the  gold  was  set  free  by  the  alteration  of  the  pyrite.  A  mashed, 
greasy  phase  of  the  garnet-quartz-epidote  rock  on  one  side  of  the  vein  is  said  to  pan  gold, 
but  whether  the  altered  pyrite  originally  occurred  in  the  altered  limestone  or  whether  the 
values  were  derived  from  the  surface  alteration  of  the  quartz  veins  is  unknown. 
Angular  fragments  of  altered  limestone  and  shale  are  common  near  the  borders  of  some 
veins.  In  such  instances  silicification  has  extended  into  the  limestone  and  these  belts, 
like  the  quartz  veins,  weather  in  relief.  Such  veins  grade  into  sheared  and  breeciated  zones 
of  silicified  limestone  and  these  again  are  reported  to  carry  values. 
Another  vein  is  similar  to  that  first  described,  but  the  shattered  quartz  is  cemented  by 
a  gray  chalcedonic  quartz,  while  still  another  at  first  sight  appears  crustified,  but  close 
inspection  shows  that  the  appearance  is  due  to  a  longitudinal  fracturing  of  the  vein  and 
subsequent  filling  by  limonite  and  the  chalcedonic  quartz.  Both  forms  of  quartz  are  said  to 
assay,  but  the  earlier  quartz  appears  to  carry  both  the  sulphides  already  mentioned  and 
slight  amounts  of  galena  as  noted  in  other  veins.  The  chalcedonic  quartz  may  appear  to 
carry  values,  because  sufficient  care  has  not  been  taken  to  eliminate  the  older  quartz  from 
samples. 
As  secondary  minerals,  limonite,  hematite,  cerussite,  free  gold,  and  a  little  malachite  were 
observed.  Probably  some  chalcop3^rite  exists  at  greater  depths.  One  of  the  last  changes 
which  these  ore  deposits  have  undergone  is  the  deposition  locally  of  a  thin  film  of  bluish- 
white  chalcedony. 
Mr.  Joseph  Mackedon,  the  manager,  states  that  in  several  prospect  holes  the  quartz  veins 
have  passed  from  altered  limestone  to  granite  without  diminution  in  size  or  value  of  content. 
From  the  striking  resemblance  of  these  veins  to  those  of  Old  Camp  this  is  to  be  expected. 
Waters  carrying  silica  and  metallic  salts  in  solution  appear  to  have  deposited  these  sub- 
stances in  strong  fractures  which  extend,  in  some  cases  at  least,  into  the  granite.  The 
country  rock  was  to  a  less  extent  impregnated.  The  quartz  veins  were  subsequently 
crushed  and  iron  oxides  and  chalcedonic  silica  were  deposited  in  the  fractures.  Simulta- 
neously, probably,  iron  pyrite  was  dissolved  and  the  gold  set  free. 
Water  and  wood  for  mining  and  domestic  purposes  are  near  at  hand,  and  the  distance  to 
the  railroad  at  Goldfield  is  25  miles. 
The  Rattlesnake  mine,  near  the  properties  described,  appears  to  be  in  the  same  rock 
formation,  and  its  ore  deposits  and  those  of  Tokop  are  said  to  be  similar.  Eight  or  ten 
years  ago  the  Rattlesnake  produced  $150,000,  and  it  has  recently  been  reopened.  The 
veins  of  Tokop,  like  those  of  Old  Camp,  seem  strong,  and  will  probably  be  permanent  to 
such  depths  as  mining  is  possible.  With  depth,  however,  the  ore  will  become  refractory 
and  may  become  leaner. 
Old  Camp. — Old  Camp,  near  Gold  Mountain,  is  situated  30  miles  west  of  south  of  Goldfield 
and  20  miles  southeast  of  Lida.     The  almost  deserted  village  is  situated  near  the  center  of 
