24  CONTRIBUTIONS    TO   ECONOMIC    GEOLOGY,  1904.        r bull.  260. 
A  similar  discussion  of  the  copper  product  of  the  United  States  is 
given  by  Mr.  W.  H.  Weed,  in  which  the  percentage  product  in  round 
numbers  is  distributed,  according  to  the  form  in  which  the  copper 
occurs  in  the  ores,  in  the  f ollowing  percentages : 
Per  cent. 
Native  ores 27 
Oxide  ores 6 
Sulphide  ores 67 
Mr.  Bain  has  made  a  similar  review  of  the  lead  and  zinc  deposits 
of  the  United  States,  based  primarily  upon  geographical  distribution. 
APPALACHIAN    REGION. 
The  reconnaissance  study  of  the  copper  deposits  of  the  Appalach- 
ian region  has  been  continued  at  intervals  during  the  last  season  by 
W.  H.  Weed,  and  a  brief  statement  of  the  results  of  his  observations 
is  given  in  this  volume.  It  is  intended  that  special  studies  shall  be 
made  of  some  of  the  more  important  copper-producing  districts  ofj 
this  region  as  soon  as  financial  and  other  conditions  permit. 
In  the  States  of  North  and  South  Carolina  the  occurrence  of  tin! 
ores  has  been  known  for  some  time.  After  the  close  of  the  field  season 
in  the  West  a  reconnaissance  examination  of  a  district  along  the  boun- 
dary of  the  two  States  was  made  by  Mr.  Graton,  under  the  direction 
of  Mr.  Waldemar  Lindgren,  which  has  shown  that  the  deposits  am 
probably  of  considerable  economic  importance,  although  they  have 
not  yet  been  so  extensively  and  systematically  developed  as  to  afford 
a  regular  and  constant  production  of  this  important  metal.  An 
account  of  the  geological  relations  and  extent  of  the  Carolina  occur- 
rence, followed  by  a  concise  statement  of  what  is  known  with  regard 
to  tin  deposits  throughout  the  rest  of  the  world,  will  be  found  in  this 
volume. 
Geological  work  in  the  region  to  be  described  in  the  Franklin 
Furnace  folio  has  been  actively  carried  on  during  the  past  summer  by 
Mr.  A.  C.  Spencer.  This  additional  work  was  considered  advisable 
on  account  of  the  importance  of  the  remarkable  zinc  deposits  of  the 
region  from  a  scientific  as  well  as  an  economic  point  of  view,  and  also 
because  the  mines  of  the  New  Jersey  Zinc  Company,  which  for  some 
years  past  have  been  closed  to  all  outside  visitors  on  account  of  pend- 
ing litigation,  have  again  been  thrown  open  for  inspection.  This  fur- 
ther investigation  has  opened  up  some  new  geological  problems,  which 
will  require  another  season's  work  for  their  solution.  The  present 
condition  of  this  work  is  not  favorable  to  the  presentation  of  the 
results  in  the  usual  abstract  form. 
