OUR  MINERAL  RESERVES.

By  George  Otis  Smith.
INTRODUCTION.
INVENTORY  OE  MINERAL  RESOURCES.
The  United  States  is  not  only  the  world’s  greatest  producer  of
mineral  wealth,  but,  so  far  as  estimates  of  the  earth’s  treasures  have
shown,  it  possesses  greater  reserves  of  most  of  the  essential  minerals ­
  than  any  other  nation.  It  is  to  our  national  mineral  resources ­
  that  the  United  States  Geological  Survey  has  given  special
attention  since  its  organization  in  1879,  for  the  congressional  enactment ­
  creating  the  Survey  specified  as  its  duties  “  the  classification
of  the  public  lands  and  examination  of  the  geological  structure,
mineral  resources,  and  products  of  the  national  domain.”
Geologic  investigations  have  been  made  with  a  view  of  determining
the  mode  of  occurrence  and  the  extent  of  distribution  not  only  of
those  minerals  and  rocks  that  possess  present  value,  but  also  of  those
that  have  only  possible  future  utility,  the  nature  of  which  may  be
as  yet  neither  known  nor  suspected.  Thus  a  geologic  map,  in  so
far  as  its  scale  permits,  is  a  graphic  inventory  both  of  the  mineral
resources  now  used  and  of  those  that  are  untouched  because  they
are  at  present  of  no  value.  He  is  indeed  a  bold  prophet,  however,
who  pretends  to  forecast  either  the  probability  or  improbability
°f  future  usefulness  of  any  raw  material.  As  has  been  illustrated
by  the  radium  mineral  carnotite,  the  minéralogie  curiosity  of  one
decade  may  become  the  valuable  ore  of  the  next.  The  principal  ore
of  aluminum,  bauxite,  was  not  even  mentioned  in  a  list  of  useful
minerals  published  by  the  Geological  Survey  25  years  ago.
The  Survey’s  annual  report  entitled  “Mineral  Resources  of  the
United  States”  contains  not  only  statistical  statements  of  production
and  consumption,  which  constitute  an  annual  census  of  the  mineral
industry  in  all  its  phases,  but  also  a  series  of  comprehensive  studies
of  the  sources  of  mineral  wealth,  with  estimates  of  the  reserves  to
be  drawn  upon  for  future  production.  The  very  nature  of  many
mineral  resources  precludes  exact  knowledge  of  the  extent  of  their
reserves,  and  the  estimates  of  other  reserves  must  be  made  roughly
quantitative.  At  best,  future  supply  and  demand  can  be  only  approximately ­
  measured,  but  the  recognition  of  this  limitation  has  not
discouraged  the  collection  of  all  available  information  concerning
the  country’s  mineral  resources.