166  CONTRIBUTIONS   TO   ECONOMIC   GEOLOGY,  1903.  [bull. 225. 
On  Anikovik  River  there  are  extensive  gravel  deposits,  which  it  is 
possible  might  be  made  to  yield  fair  returns,  either  in  gold  or  in  tin, 
if  economically  worked  on  an  extensive  scale  by  hydraulic  methods. 
Sufficient  water  for  this  purpose  can  probably  be  obtained  either  from 
the  head  of  Anikovik  River  or  from  Kanauguk  River. 
REPORTED  OCCURRENCES  OF  STREAM  TIN. 
Prospectors  who  are  familiar  with  the  stream  tin  from  Buck  Creek 
report  finding  small  amounts  of  the  ore  in  a  great  many  streams  in 
the  York  region;  among  these  are  Baituk  and  Kigezruk  creeks,  flow- 
ing into  Bering  Sea;  Banner  Creek,  a  tributary  of  Anikovik  River; 
several  small  creeks  flowing  into  Lopp  Lagoon;  Clara  Creek,  a  tribu- 
tary of  Mint  River;  and  York  Creek,  a  tributary  of  Pinguk  River. 
Stream  tin  has  been  reported  from  all  parts  of  Seward  Peninsula 
where  gold  mining  is  in  progress,  but  except  in  respect  to  the  York 
region,  these  reports  have  generally  been  found  to  be  without  foun- 
dation. 
REPORTED  OCCURRENCES  OF  LODE  ORE. 
Discoveries  of  tin-bearing  lodes  have  been  reported  by  prospectors 
from  many  other  localities  in  Seward  Peninsula,  some  of  which  de- 
serve notice,  since  geologic  conditions  are  known  to  be  promising. 
These  are  the  localities  in  which  intrusive  stocks  of  granite  occur,  but 
in  no  case  has  the  presence  of  tin  ore  in  appreciable  amounts  been 
confirmed  by  the  Geological  Survey,  and  they  can  be  passed  over  with 
mere  mention.  These  localities  are  Brooks  Mountain,  near  the  head 
of  Lost  River,  and  4  miles  north  of  the  Lost  River  tin  deposits;  the 
hills  east  of  Don  River;  Ears  Mountain,  about  50  miles  north  of  Port 
Clarence;  Hot  Springs,  about  70  miles  northeast  of  Port  Clarence; 
Asses  Ears,  about  20  miles  south  of  Kotzebue  Sound,  and  the  Dio- 
mede  Islands,  in  Bering  Strait,  about  30  miles  west  of  Cape  Prince  of 
Wales. a 
CONCLUSION. 
The  above  facts  show  cassiterite  to  be  rather  irregularly  distributed 
through  an  area  of  about  450  square  miles,  embracing  the  western  end 
of  Seward  Peninsula. 
At  three  localities — Anikovik  River,  Buhner  Creek,  and  Buck 
Creek — its  occurrence  in  placers  has  been  verified  by  the  Geological 
Survey,  and  lode  tin  has  been  found  by  the  Survey  at  Lost  River  and 
a  Since  this  was  written,  four  specimens  obtained  from  Ears  Mountain  have  been  analyzed  by  Mr. 
Eugene  C  Sullivan,  chemist  of  the  U.  S.  Geological  Survey.  In  each  case  traces  of  tin  amounting  to 
a  few  hundredths  of  1  per  cent  were  found.  The  rocks  assayed  consist  of  a  granite-porphyry  in 
which  the  original  constituents  are  largely  replaced  by  calcite,  tourmaline,  and  pyrrhotite.  The 
occurrence  of  cassiterite  in  the  Asses  Ears  region  has  been  confirmed  by  Dr.  Cabell  Whitehead,  of  the 
Alaska  Banking  and  Safe  Deposit  Company,  who  found  it  in  fine  grains  in  the  placer  gold  from  Old 
Glory  Creek. 
