196  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1905. 
VANCOUVER   AND   TEXADA    ISLANDS,  BRITISH    COLUMBIA. 
The  best-known  sources  of  iron  ore  for  the  northwestern  United  Stales  are  Texada  Island 
and  the  west  side  of  Vancouver  Island,  British  Columbia,  especially  near  Barclay  Sound. 
The  furnace  at  Port  Townsend,  Wash.,  has  drawn  its  ore  from  the  first  of  these  localitiei 
and  in  plans  for  the  use  of  this  ore  American  capital  has  largely  figured.  Each  of  these 
localities  was  visited  in  1904. 
Without  going  into  detailed  descriptions,  it  may  he  reported  that  these  ores  are  largely 
magnetite,  carrying  usually  considerable  amounts  of  iron  and  copper  sulphides,  apati:e, 
amphibole,  and  garnet.  At  the  surface  is  an  oxidized  zone,  usually  a  few  inches  thick,  of 
limonite  and  while  sulphate.  The  metallic-iron  content  averages  from  35  to  GO  per  cent! 
and  above  in  different  deposits,  the  Texada  ores  and  a  part  of  those  on  Barclay  Sound  hav- 
ing the  higher  percentages.  The  sulphur  content  is  for  the  most  pari  high,  requiring  that 
I  he  ores  he  roasted.  The1  copper  content  is  also  high,  particularly  in  the  Texada  ores  (2  per 
cent  ).     The  phosphorus  in  the  higher  grade  ores  is  mainly  below  the  Bessemer  limit. 
The  ores  occur  a!  or  near  the  contact  of  acid  igneous  rocks  with  limestone  and  are  obvi- 
ously repla<  ementsof  limestone.  In  some  instances  the  ore  may  be  seen  cut  irelv  surrounded 
by  igneous  rock,  evident  ly  a  replacement  of  limestone  intruded  by  and  caught  up  in  igneous 
rock  near  the  contact.  'Flic  contacts  of  the  igneous  rock  with  the  ore  are  characteristically 
sharp  and  present  no  gradation  features  that  would  accord  with  the  view  that  1  he  ore  repre- 
sents  segregations  from  igneous  rocks.  The  abundant  occurrence  of  lime  garnet,  however, 
both  in  1  he  ore  and  in  the  crystalline  limestone  adjacent  to  the  igneous  contact,  suggests 
the  concentration  of  the  deposit  under  the  influence  of  igneous  intrusion.  The  shape,  size, 
and  vertical  extent  of  the  deposits  have  for  the  most  part  not  been  determined,  but  it  is 
obvious  that  a  huge  tonnage  of  iron  ore  is  here  to  be  obtained.  In  the  Barclay  Sound  area 
several  pits  and  tunnels  have  penel  rated  ore  from  a  few  feel  to  a  maximum  of  1  10  fee1!  hori- 
zontally  and  approximately  the  same  amount  vertically.  In  Texada  Island  bells  have  a 
maximum  thickness  of  about  100  feel  and  in  one  place  a  bell  has  been  cut  by  a  tunnel  300 
feel  below  1  he  surface.  I  lere  t  he  ore  is  as  wide  and  apparently  of  as  good  a  grade  as  at  the 
surface. 
COLORADO. 
In  company  with  C.  R.  Van  Ilise  a  reconnaissance  was  made  in  1905  of  the  iron  ores  south 
of  Ashcroft,  in  Pitkin  and  Gunnison  counties,  near  White  Pine,  Gunnison  County;  and  in 
the  Cebolla  district,  also  in  Gunnison  County. 
About  0  miles  south  of  Ashcroft  iron  ores  appear  on  both  sides  of  the  Elk  Mountains 
divide,  near  its  junction  with  the  Saguache  Range,  in  Pitkin  and  Gunnison  counties.  At 
"Cooper's,"  on  the  northwest  side  of  the  divide,  at  an  elevation  of  between  1 1  ,(XK)  and 
12,000  feet,  the  iron  lies  on  the  steep  face  of  the  ridge.  It  is  apparently  underlain  and 
overlain  by  limestone,  and  stringers  of  it  may  be  seen  extending  into  the  limestone.  The 
dip  of  the  iron  belt  seems  to  be  down  the  slope.  Eight  tunnels  have  been  driven  into  the 
iron,  the  longest  one  122  feet  and  the  shortest  40  feet  in  iron.  The  vertical  distance  bet  ween 
the  highest  and  lowest  tunnels  is  between  75  and  100  feet.  The  greatest  distance  bet  ween 
the  tunnels  along  the  slope  is  300  feet.  The  iron  may  be  seen  to  extend  along  the  slope  for 
about  500  feet.  These  figures  are  not  exact.  Specimens  taken  at  random  showed  a 
metallic-iron  content  varying  from  30  to  (34  per  cent,  phosphorus  0.007  to  0.069  per  cent, 
and  sulphur  0.077  to  0.970  per  cent.  The  bulk  of  the  ore  is  high  in  iron  and  sulphur  and 
low  in  phosphorus.  The  iron  at  the  surface  is  magnetite,  with  cavities  filled  with  secondary 
limonite  and  quartz.  Back  in  the  tunnels  the  ore  becomes  harder  and  contains  unaltered 
sulphides,  garnet,  epidote,  and  feldspar,  suggesting  original  concentration  under  the  influ- 
ence of  igneous  rocks,  which  appear  on  the  adjacent  ridges. 
On  the  southeast  side  of  the  divide  the  iron  ores,  supposedly  continuous  with  those  of  the 
northwest  side,  extend  in  a  belt  along  the  east  side  of  Taylors  Peak  and  reappear  on  Crystal 
Peak  and  Mount  Tilton.     They  were  examined  at  Taylors  Peak,  the  principal  occurrence, 
