METALLIFEROUS    ORES.  17 
When  this  method  of  treating  statistics  shall  have  been  extended  to  the  other  metals 
the  discussion  of  the  results  from  the  geological  standpoint  will  form  an  important  part 
of  the  work  of  the  section  of  metalliferous  ores. 
The  work  more  strictly  belonging  to  this  section  (excluding  that  in  Alaska)  that  has 
been  carried  on  during  the  year  will  be  noted  in  geographic  order: 
UNITED    STATES    IN    GENERAL. 
Mr  W.  H.  Weed  has  compiled  from  certain  publications  a  general  review  of  the  impor- 
tant copper  deposits  of  the  United  States  which  will,  it  is  thought,  be  found  of  value  to 
all  interested  in  mines  as  furnishing  in  condensed  form  the  geological  data  necessary  for 
an  understanding  of  the  manner  of  occurrence  of  the  principal  copper-producing  ores. 
APPALACHIAN    REGION. 
Mr.  Weed  has  continued  from  time  to  time  during  the  year  his  reconnaissance  studies 
of  the  copper  deposits  of  the  Appalachian  region,  the  manuscript  of  which,  as  already 
noted,  is  very  nearly  ready  for  publication,  and  it  is  hoped  that  it  will  be  issued  very 
shortly  after  the  appearance  of  the  present  bulletin. 
Mr.  Spencer  has  carried  om  during  the  summer  a  special  study  of  the  geological  relations 
of  the  magnetite  deposits  of  the  Franklin  Furnace  quadrangle,  in  New  Jersey,  with  the 
idea  that  the  solution  of  this  problem  may  throw  important  light  on  the  mooted  question 
of  the  origin  of  the  Franklin  Furnace  zinc  ores. 
Mr.  Charles  Palache  has  been  occupied  during  the  same  time  in  making  a  mineralogical 
study  of  the  Franklin  Furnace  ores,  which  it  is  hoped  will  also  throw  some  light  on  their 
genesis. 
MISSISSIPPI    VALLEY    REGION. 
At  the  commencement  of  the  field  season  Mr.  Bain,  who  has  hitherto  had  charge  of  the 
work  in  this  region,  resigned  his  position  on  the  Survey  to  accept  the  directorship  of  the 
Illinois  State  Geological  Survey;  consequently,  no  economic  field  work  has  been  carried 
on  in  this  region  during  the  year. 
As  reconnaissance  examinations,  in  intervals  of  other  work,  Mr.  E.  O.  Ulrich  has 
examined  the  copper  deposits  in  sedimentary  rocks  that  are  of  widespread  occurrence  in 
northern  Texas.  Mr.  G.  B.  Richardson  has  also  studied  the  geological  relations  of  the 
tin  deposits  of  the  Franklin  Mountains,  near  El  Paso,  the  results  of  which  appear  in  this 
bulletin. 
ROCKY    MOUNTAIN    REGION. 
Arizona. — The  work  planned  for  Arizona  for  the  field  season  had  been  an  economic 
survey  of  the  Tombstone  mining  district  and  reconnaissance  examinations  of  the  smaller 
mining  districts  of  the  Territory  by  Mr.  F.  L.  Ransome  and  his  assistants.  When,  however, 
at  the  commencement  of  the  field  season,  Mr.  Spurr  resigned  his  position  on  the  Survey, 
it  was  judged  best  to  assign  Mr.  Ransome  to  the  economic  survey  of  the  Goldfield  and 
Bullfrog  districts  of  Nevada,  which  originally  had  been  allotted  to  Mr.  Spurr;  hence,  the 
field  work  that  has  been  done  in  Arizona  during  the  year  has  consisted  only  of  visits  by 
the  writer  to  the  Tombstone,  Bisbee,  and  Globe  districts  for  the  purpose  of  keeping  in 
touch  with  geological  phenomena  newly  exposed  in  these  regions  by  recent  mining 
developments. 
Colorado.— In  Colorado  a  geological  field  party  has  been  engaged  during  the  summer 
in  mapping  more  carefully  the  geology  of  portions  of  northwestern  Colorado,  which  will 
be  opened  by  the  new  "MoiTatt  road"  tshat  is  destined  to  connect  Denver  with  Salt  Lake 
City.  In  the  course  of  this  work,  Mr.  H.  S.  Gale  was  enabled  to  make  a  reconnaissance 
examination  of  the  Hahns  Peak  gold  field  and  map  its  geology.  His  report  on  this  district 
is  included  in  the  present  volume. 
Bull.  285—06 2 
