164  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull.  225. 
iron  minerals  that  are  frequently  mistaken  for  it,  since  they  give  a 
distinct  red,  black,  or  brown  powder. 
A  number  of  specimens  were  obtained  that  showed  pieces  of  quartz 
and  slate  from  the  bed  rock  still  attached  to  them,  leaving  no  doubt  as 
to  the  origin  of  the  fragments.  Some  small  pieces  of  cassiterite  have 
been  found  inclosed  between  the  fragments  of  slate,  showing  that  they 
were  broken  out  of  small  veins  in  the  slate. 
Near  the  head  of  Buck  Creek  Mr.  Edgar  Rickard,  in  1902,  tested 
the  gravels  and  found  them  to  contain  about  8  pounds  of  60  per  cent 
ore  to  the  cubic  yard.  Mr.  Hess  saw  pannings  made  at  a  number  of 
places  along  Buck  Creek,  but  not  enough  to  thoroughly  test  the  rich- 
ness of  the  ground.  The  best  seen  came  from  immediately  above 
the  mouth  of  Sutter  Creek,  where  a  drain  ditch  from  2  to  2£  feet  deep 
was  in  construction.  From  these  pannings  Mr.  Hess  estimates  that 
the  gravels  contained  approximately  27  pounds  of  60  per  cent  concen- 
trates to  the  cubic  yard  of  gravel.  The  gravel  deposit  here  was  about 
5i  feet  thick  and  approximately  100  feet  wide.  At  this  point  there 
seemed  to  be  no  difference  in  the  distribution  of  the  tin  ore  through 
the  gravels  from  the  surface  down,  and  the  largest  pieces  were  found 
on  the  surface. 
From  the  evidence  of  prospectors  it  seems  that  this  uniform  distri- 
bution through  the  gravel  prevails  generally  along  the  creek,  though 
at  one  place  it  was  found  to  be  richer  on  the  bed  rock. 
On  Grouse  Creek  below  the  mouth  of  Buck  the  amount  of  tin  ore  is 
reported  to  be  very  small,  and  Mr.  Hess  found  no  evidence  of  pros- 
pecting in  this  section.  The  gravel  deposits  of  Grouse  Creek  are 
more  extensive  than  those  on  Buck,  and  seem  to  be  worthy  of  attention. 
No  large  amounts  of  cassiterite  have  been  reported  from  either  Gold 
Creek,  a  tributary  of  Grouse  above  Buck,  or  from  Sutter,  a  large 
southern  tributary  of  Buck,  nor  has  much  gold  been  found  there. 
To  briefty  summarize  the  evidence  regarding  the  Buck  Creek  region, 
tin  ore  has  been  found  in  the  gravels  of  Buck  Creek  from  its  mouth  to 
within  a  mile  of  its  head.  The  pay  streak  is  confined  to  the  present 
stream- bed  and  flood-plain  deposits,  and  probably  varies  from  10  or  12 
feet  to  150  feet  in  width.  In  the  present  creek  bed  the  ore  is  found 
from  the  surface  down.  Outside  the  creek  bed  there  is  a  covering  of 
moss  and  muck  above  the  gravels.  No  ore  is  known  to  have  been 
found  on  the  hillsides  surrounding  Buck  Creek  or  on  the  plateau  sur- 
face in  which  Buck  Creek  is  incised,  though  such  an  occurrence  is  to 
be  expected.  The  thickness  of  tin-bearing  gravels  varies  from  a  few 
inches  to  4  or  5  feet.  Estimates  of  the  amount  of  tin  ore  in  the 
gravels  vary  from  8  to  27  pounds  per  cubic  yard,  but  probably  the 
former  amount  is  more  nearly  the  average  of  the  creek. 
Tin  ore  was  discovered  on  Buck  Creek  in  the  fall  of  1901,  and  some 
mining  for  stream  tin  was  attempted  in  the  summer  of  1902.     As  a 
