46  PKE-CAMBKIA^    GEOLOGY   OF    NORTH   AMERICA. 
Table  of  correlation  of  pre- Cambrian  rocks  of  North  America — Continued. 
Washington,  Oregon, 
and  California. ' 
British  Columbia,  Yukon,  and  Alaska. 
Mexico. 
Unclassified       pre-Cam- 
Algonkian  (late) : 
Doubtfully  pre-Cam- 
Unclassified      pre-Cam- 
brian  (?): 
Nisconlith 
brian: 
brian: 
Gneisses,    schists, 
group  and 
Birch  Creek  schist 
Crystalline      schists 
sediments,  and  vol- 
partof  Ad- 
of Tanana-Yu- 
and  granites,  prin- 
canics of  northern 
ams   Lake 
kon  region. 
cipally   along   the 
Cascades   and   In- 
group    of 
Totsen   group  of 
Pacific  slope. 
ternational  Bound- 
British Co- 
northern Alas- 
ary region  of  north- 
lumbia. 
ka. 
eastern    Washing- 
Belt series  of 
•Belt(?). 
Indian    River 
ton,  Klamath 
b  o  undary 
group  of  Klon- 
Mountains of  Ore- 
region. 
dike. 
gon  and  California, 
Down  ward 
Kuzitrin  group  of 
and  other  districts. 
extension 
of     Bow 
River 
group. 
Seward    Penin- 
sula. 
Kigluaik  group  of 
Seward    Penin- 
sula. 
Unclassified  pre-Cam- 
brian: 
Shu  swap  group 
and    "  Lauren- 
tian"  series  of 
British  Colum- 
bia.     Contains 
rocks  probably 
belonging    to 
both  the  Arch- 
e  a  n    and    the 
Algonkian. 
Pelly  gneiss  (?). 
