GENERAL   ACCOUNT    OF    THE    PRE-CAMBRIAN    ROCKS.  45 
Table  of  correlation  of  pre- Cambrian  rocks  of  North  America — Continued. 
Texas. 
Black  Hills. 
Wyoming. 
Algonkian  (?): 
Algonkian: 
Algonkian: 
Unclassified      pre-Cam- 
Central    Texas. 
Slates,    quartzites, 
Granites  and 
brian: 
Llano     series. 
schists,  and  iron 
gneisses  intrusive 
Granites   and 
Sediments    and 
format  ion,  i  n  - 
in  sediments  list- 
gneisses of  Sierra 
Madre,      Medicine 
schists,      intruded 
truded  by  granite. 
ed  below. 
by    granites     and 
Whalen  group  of 
Hartville  district. 
Bow,  Lar  am  ie, 
gneisses. 
Sweetwater,  Wind 
Western   Texas    (El 
Isolated  areas  be- 
River,   Wyoming, 
Paso  County). 
tween     Hartville 
Rattlesnake,  Gros 
Sediments    and 
and  Black  Hills. 
Ventre,  Teton, 
schists  in  Franklin 
Mica  schists  of  Sun- 
Absaroka, and 
and  Diablo  moun- 
dance quadrangle. 
Bighorn  ranges. 
tains,  intruded  bv 
Sediments  in  Hal- 
granite. 
lock  and  Plum- 
bago canyons,  in 
the  Sierra  Madre 
(Grand  Encamp- 
ment) ,  in  Medi- 
cine Bow  Moun- 
tains, in  Semi- 
noe  Mountains, 
in  Sweetwater 
district  of  the 
Wind  River 
Range,  and  in 
Mount  Sheridan 
near  Yellowstone 
Park. 
Colorado. 
New  Mexico. 
Arizona. 
Algonkian: 
Unclassified 
pre-Cambrian: 
Algonkian  (late) : 
Sediments,  mainly  quartzite, 
Granites 
,  gneisses,  schists, 
Grand  Canyon 
of  Needle  Mountains,  Un- 
quartzites,  and  other  sedi- 
group.   Per- 
compahgre Canyon,    Rico 
ments 
of  central  mountain 
haps  to  be  spe- 
Mountains, and  Front 
system,    including    Mora, 
cifically      corre- 
Range.    Perhaps    also 
Taos, 
Santa    Fe,  Sandia, 
lated    with    the 
C  h  u  a  r 
quartzite  of  Salida  district. 
Magda 
lena,  Caballos,  and 
Belt     series     of 
•   group. 
Quartzites  of  Needle  Moun- 
Franklin mountains;  also 
Montana    and 
U  n  k  a  r 
tains  perhaps  to  be  specific- 
Burro 
and  other  ranges  of 
the  quartzites  of 
group. 
ally    correlated    with    the 
desert 
-range  province. 
Needle ,   Wa- 
Belt series  of  Montana  and 
satch,  and  Uinta 
the  quartzites  of  the  Uinta 
and   Wasatch    mountains 
mountains. 
Pinal    schist    (sedimentary) 
and  the  Grand  Canyon. 
of    southeastern    Arizona, 
Certain    greenstone    schists 
including     Globe,     Bisbee, 
and  Bradshaw districts  (?), 
and  allied  rocks  of  Salida 
district  and  Needle  Moun- 
possibly to  be   correlated 
tains. 
with  Grand  Canyon  series. 
Intruded  by  large  masses  of 
granite,  such  as  Pikes  Peak 
granite. 
Tl  nfnnfnrmitv 
Unconformit  v 
VJ  ILKsKJlLLXJ  LlLLLVy  * 
Archean  (?): 
Archean: 
G ranites ,  gneisses ,  and  schists 
Granites,    gneisses,    and 
schists  of  Grand  Canyon. 
of  Front,  Wet,  Sangre  de 
Cristo,  Sawatch,  and  Nee- 
dle   mountains.    May    in- 
clude sedimentary  schists 
of  Front  Range. 
