collier.]       TIN    DEPOSITS    OF    THE    YORK    REGION,    ALASKA.  161 
the  prevailing  south  winds  of  summer  tne  harbor  is  practically  an  open 
roadstead,  and  affords  little  if  any  better  landing*  facilities  than  can  be 
found  at  Nome  or  York.  Tin  City  is  10  miles  distant,  and  northwest 
of  good  anchorage  on  Port  Clarence.  East  of  Cape  Mountain,  the  flat- 
topped  upland  called  the  York  Plateau  has  an  elevation  of  about  300 
feet,  and  is  made  up  of  limestones  and  interbedded  slates  which  have 
been  already  described.  Cape  Mountain  itself  is  composed  almost 
entirely  of  granite  in  the  form  of  a  boss  or  stock  intruded  in  the  lime- 
stone. The  contact  relations  of  the  granite  and  limestone  have  not 
been  studied  in  detail,  but,  from  data  gathered  in  the  reconnaissance, 
it  appears  that  the  granite  cuts  across  the  stratification  of  the  limestone. 
The  writer's  visit  to  this  locality  was  of  necessity  a  very  hasty  one, 
and  he  was  embarrassed  by  exceedingly  rainy  weather,  so  that  his 
observations  were  limited  in  extent.  However,  specimens  of  tin  ore 
were  obtained,  which  undoubtedly  came  from  the  granite  of  the 
mountain,  though  the  ore  was  not  definitely  traced  to  its  position  in 
the  bed  rock.  It  is  reported  that  tin  ore  has  been  found  at  three 
distinct  points  on  this  mountain,  and  that  it  occurs  in  somewhat  irreg- 
ular deposits  which  have  an  east-west  trend.  Several  tunnels  were 
being  driven  into  the  mountain,  but  it  was  reported  that  ore  bodies 
had  not  been  found  in  any  of  them. 
The  ore  obtained  at  Cape  Mountain  differs  in  general  appearance 
from  that  seen  on  Lost  River.  Large  pieces  of  nearly  pure  cassiterite, 
one  of  which  weighed  about  9  pounds,  are  said  to  have  been  found  on 
the  surface  of  the  mountain.  A  specimen  obtained  by  the  writer 
weighs  approximate^  2  pounds,  and  is  nearly  pure  cassiterite,  showing 
little,  if  any,  outward  signs  of  crystallization,  but  has  embedded  in  it 
and  surrounding  it  much  tourmaline  in  slender  needles.  While  in  this 
vicinity  the  writer  was  shown  a  number  of  large  crystals  of  cassiterite 
which  were  nearly  colorless  and  practically  transparent.  Much  of 
the  supposed  tin  ore  contains  a  great  many  dark  minerals  that  have 
been  mistaken  for  cassiterite,  but  are  simply  tourmaline  in  slender 
black  or  brown  needles. 
Tin  ore  was  discovered  on  Cape  Mountain  in  July,  1902,  and  exten- 
sive developments  were  planned  for  the  season  of  1903.  The  plan  of 
this  work  was  as  follows:  A  large  dynamo  driven  by  a  gasoline  engine 
was  to  be  placed  near  the  beach  at  the  point  now  known  as  Tin  City, 
and  from  this  dynamo  wires  were  to  be  run  to  several  points  on  the 
mountain  to  supply  power  for  electric  drills.  By  the  use  of  these 
drills  it  was  expected  that  prospect  tunnels  could  be  rapidly  extended 
into  the  heart  of  the  mountain,  in  order  to  crosscut  the  ledges  from 
which  the  float  ore,  above  described,  had  been  derived.  After  spend- 
ing nearly  the  whole  of  the  season  of  1903  in  getting  the  machinery 
in  place,  it  was  found  that  the  engine  for  driving  the  dynamo  was 
defective,  and  the  plan  for  development  work  during  the  winter  of 
Bull.  225—04 11 
