vanhise.]  THE    CORDILLERAS.      '  337 
undergone   repeated   metamorphisni.    Aside  from  these  the  earliest 
inefcamorphic  rocks  of  the  coast  are  probably  Cretaceous. 
Becker,86  in  1891,  describes  the  sierra  between  the  Stanislaus  and 
Truekee  rivers  as  being  chiefly  granite  and  diorite  overlain  in  part  by 
andesite  and  basalt.  The  granite  and  other  granular  rocks  are  inter- 
sected by  fissures  at  short  intervals  which  are  believed  to  be  early  Cre- 
taceous. 
LITERATURE   OF   WASHINGTON. 
Gibes,87  in  1855,  states  that  in  central  Washington,  in  the  valley  of 
the  Methow,  is  found  granite,  syenite  and  gneiss,  well  characterized 
and  blended  with  each  other.  The  syenite  is  often  divided  by  joints  so 
as  almost  to  appear  stratified  and  to  give  its  perpendicular  walls  the 
semblance  of  artificial  construction.  The  gneiss  is  found  both  hori- 
zontal and  displaced  by  the  intrusion  of  trap.  Along  the  Columbia 
river  was  found  syenite,  granite,  gneiss,  quartzose  rocks,  talcose  slate 
and  greenstone. 
LITERATURE   OF   BRITISH   COLUMBIA. 
Bichardson,88  in  1872,  mentions  crystalline  rocks  on  the  east  coast 
of  Vancouver  which  are  pre  Carboniferous  and  may  be  of  Laurentian 
age. 
Eichardson,89  in  1873,  finds  below  the  coal-bearing  series  of  Van- 
couver and  Queen  Charlotte  islands  crystalline  limestones,  diorites,  red 
and  green  slates,  the  age  of  which  is  uncertain,  but  are  probably  Silur- 
ian or  later. 
Eichardson,90  in  1876,  finds  crystalline  rocks  throughout  a  wide- 
spread area  in  British  Columbia,  extending  through  7  degrees  of  lati- 
tude, from  .New  Westminster  on  the  Fraser  river  to  Wrangel  on  the 
Stickeen  river,  and  through  6  degrees  of  longitude,  from  Vancouver  to 
Cariboo  and  Tete  Jaune  cache.     While  not  able  to  speak  authorita- 
tively on  the  age  of  this  great  series  of  crystalline  rocks  or  to  say 
hether  different  portions  of  them  will  be  proved  to  belong  to  distinct 
pochs,  they  present  such  a  wonderful  uniformity  in  character  as  to 
avor  the  idea  that  they  constitute  one  great  and  widespread  series, 
hey  are  doubtless  the  gold-bearing  rocks  of  British  Columbia. 
Selwyn,91  in  1877,  in  a  report  on  exploration  in  British  Columbia, 
ivides  the  rocks  into  five  divisions  from  above  downward.     Division 
bur  consists  of  semicrystalline  rocks,  among  which  are  limestones, 
hales,  mica-schists  and  quartzites,  which  appear  to  have  obscure  fos- 
ils.    The  age  of  these  rocks  is  not  clearly  determined.    Division  five 
onsists  of  granitic  rocks. 
Macoun,92  in  1877,  finds  granite-gneiss  and  gneiss  a  few  miles  up  the 
Juatre  Fourches  river,  which  are  referred  to  the  Laurentian. 
Dawson,  (G-.  M.)M  in  1877,  states  that  a  crystalline  series  occurs  in 
le  Cascade  mountains  about  Eagle  and  Tat  la  lakes.     These  are  chiefly 
ighly  crystalline  gneisses,  granites  and  diorites. 
Bull.  86—22 
