COPPER    MINES    OF    THE    UNITED    STATES MICHIGAN.  109 
time  as  the  gangue  minerals.  The  epidote,  specularite,  and  garnet,  as  described  by  Palachc,a  present 
clear  evidence  of  simultaneous  crystallization.  At  the  Peacock  mine  a  large  body  of  medium-grade  ore 
of  this  character  was  embedded  in  diorite.  No  limestone  showed  here,  but  I  am  informed  that  a  lower 
tunnel  has  lately  encountered  limestone  below  the  croppings. 
Other  claims  in  which  the  ore  occurs  on  the  contact  of  limestone  and  diorite  are  the  White  Monument, 
Alaska,  Blue  Jacket,  Helena,  and  Decorah.  Considerable  masses  of  ore  have  been  exposed  at  some  con- 
tacts, though  the  distribution  is  extremely  irregular.  In  the  Blue  Jacket  a  rich  body  of  bornite  and 
chalcocite  was  lately  found,  and  it  is  reported  that  500  tons  of  40  per  cent  ore  has  been  shipped  from  this 
mine  during  the  past  summer.  During  1900  the  Boston  and  Seven  Devils  Copper  Company  shipped 
from  the  Peacock  and  other  claims  260  tons  containing  23  per  cent  of  copper  besides  8  ounces  of  silver 
and  0.04  ounce  of  gold  per  ton. 
Still  another  copper  deposit  in  Idaho  which  appears  to  belong  to  this  type  is  the  White  Knob  mine, 
near  Houston,  in  Lost  River  Valley.  Mr.  W.  Darlington,  the  general  manager  of  the  company,  has 
kindly  furnished  the  following  information:  The  ore  occurs  as  a  deposit  between  granite  and  limestone; 
the  trend  of  the  contact  is  north  and  south,  the  limestone  lying  to  the  east  and  the  granite  to  the  west. 
On  the  surface  the  ore-bearing  zone  is  1,200  feet  in  length  and  (as  a  maximum)  400  feet  in  width.  The 
minerals  are  hematite,  magnetite,  chalcopyrite,  pyrite,  and  a  little  galena,  in  a  gangue  of  garnet  and 
coarsely  crystalline  calcite.  A  porphyry  dike  also  occurs  on  the  contact,  complicating  the  geological 
relations.  The  oxidized  zone  is  very  deep,  water  not  having  been  encountered  until  the  depth  of  GOO 
feet  was  reached  in  the  shaft. 
MICHIGAN. 
The  Lake  Superior  copper  district  has  shown  a  larger  production  for  1905  than  at  any 
time  in  its  previous  history.  There  were  nineteen  regular  producers,  and  the  output  for 
the  year  is  estimated  at  220,950,000  pounds,  valued  at  about  $35,000,000,  an  increase  of 
nearly  12,600,000  pounds  over  that  of  the  preceding  year.  As  usual,  the  largest  output 
and  largest  gain  is  made  by  the  Calumet  and  Hecla  Company,  which  furnished  nearly 
27  per  cent  of  the  total  production  for  the  year,  the  chief  production  coming  from  the 
"Calwmet  conglomerate/'  as  in  former  years.  The  "Kearsarge  amygdaloid  belt"  has  also 
furnished  part  of  the  Calumet  production.  The  only  new  producer  is  the  Allouez,  the  ore 
from  this  mine  being  treated  in  the  Centennial  stamp  mill.  The  Copper  Range  properties 
were  extensively  developed,  insuring  an  increased  output  for  the  current  year.  Among  the 
older  properties  there  has  been  a  marked  revival  of  interest  and  many  of  the  mines  are  now 
being  reopened,  owing  to  the  high  price  of  copper.  Among  the  producers  which  may  be 
expected  to  add  to  the  output  of  the  district  in  the  near  future  may  be  mentioned  the 
Keweenaw  Copper  Company,  wrhich  is  under  the  control  of  the  Amalgamated  Copper  inter- 
ests. The  Resolute,  owned  by  the  same  interests;  the  Delaware,  recently  purchased  by 
the  Calumet  and  Hecla;  and  the  Cliff,  owned  by  the  Tamarack  Company,  have  also  been 
extensively  developed  during  the  year.  The  Erie-Ontario  Development  Company  and  the 
King  Philip  Mining  Company  are  among  the  newer  ventures.  The  Phoenix  is  the  only  mine 
abandoned,  as  the  St.  Clair  vein  proved  too  narrow  to  permit  profitable  working. 
Eight  mines  paid  dividends,  the  total  being  $9,014,600,  of  which  $5,000,000  was  paid  out 
by  the  Calumet  and  Hecla. 
The  Lake  Superior  district  is  unique  among  the  copper  regions  of  the  world.  Some- 
what similar  deposits  occur  in  other  places,  but  they  are  small  and  as  yet  un worked.  The 
copper  occurs  in  a  native  state,  and  the  extent  of  the  ore-bearing  beds,  the  nearly  uniform 
dip  of  the  beds,  and  the  fact  that  the  copper  is  present  for  long  distances  along  a  bed  render 
mining  a  stable  industry  in  this  district.  These  conditions  and  well-established  systems 
of  transportation  for  ore  and  supplies  permit  such  cheap  mining  that  ores  containing  less 
than  1  per  cent  of  copper  are  worked  at  a  profit.  The  dividends  paid  by  the  different 
mines  operating  this  district  aggregate  about  $160,000,000,  and  are  greater  than  those 
of  any  other  mining  district  in  the  world.  The  annual  production  is  about  15  per  cent  of 
the  copper  output  of  the  world.  The  mining  companies  in  operation  are  increasing  their 
output  year  by  year  and  new  mines  are  being  developed,  and  yet  it  may  be  confidently 
asserted  that  there  is  no  present  sign  of  exhaustion  of  the  region. 
a  Am.  Jour  Sci.,  3d  ser.,  vol.  8,  October,  1899. 
