THE  PRODUCTION  OF  SILVER  IN  THE  UNITED  STATES  IN  1904. 
By   Waldemar  Lindgren. 
INTRODUCTION. 
A  preliminary  estimate  by  the  Director  of  the  Mint  places  the  pro- 
duction of  silver  in  the  United  States  at  53,603,000  fine  ounces,  and 
in  the  same  estimate  the  amounts  contributed  by  the  several  States 
are  enumerated.  Although  detailed  statistics  are  not  3ret  available, 
it  may  be  worth  while  to  attempt  an  approximate  distribution  of  this 
product  among  the  different  classes  of  ore,  and  also,  so  far  as  possible, 
among  the  different  classes  of  ore  deposits.  The  data  available  for 
such  classification,  which  is  here  for  the  first  time  attempted,  are  nec- 
essarily incomplete,  and  the  figures  given  must  be  considered  merely 
as  estimates.  Much  information  concerning  this  question  is  con- 
tained in  the  reports  of  the  Bureau  of  the  Mint.  Besides  this,  many 
data  have  been  obtained  by  the  mining  geologists  of  the  Geological 
Survey  and  from  reports  in  the  technical  press. 
The  production  of  silver  in  the  United  States  has  been  practically 
stationary  since  1890,  at  figures  averaging  55,000,000  ounces.  Dur- 
ing 1892  and  1893  the  output  rose  to,  respectively,  63,500,000  and  60,- 
000,000  ounces,  only  to  drop  suddenly  during  1894  to  49,500,000 
ounces.  The  estimate  for  1904,  as  stated  above,  is  53,603,000  ounces, 
a  decrease  of  about  700,000  ounces  from  the  preceding  year. 
In  subdividing  this  amount  a  basis  has  been  adopted  similar  to  that 
employed  in  the  subdivision  of  the  gold  production.  The  different 
classes  of  ores  to  which  the  production  can  be  traced  are  as  follows : 
(1)  Silver  derived  from  placers. 
(2)  Silver  derived  from  dry  or  quartzose  ores. 
(3)  Silver  derived  from  copper  ores. 
(4)  Silver  derived  from  lead  ores. 
The  second  class  is  further  subdivided  according  to  the  geological 
character  of  the  veins,  one  division  being  formed  by  the  pre-Cambrian 
veins,  another  by  the  Mesozoic  gold-quartz  veins  of  the  Pacific  coast 
belt,  and  a  third  by  the  Tertiary  gold  and  gold-silver  veins,  which 
appear  chiefly  in  connection  with  eruptive  rocks  of  that  age. 
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