vanhisb.  ]  THE    CORDILLERAS.  307 
ferior  conformable  nonfossiliferous  quartzite  and  then  an  unconformity 
before  the  rocks  are  reached  referred  to  the  Archean,  the  conclusion  can 
not  be  questioned.  Also  it  is  probable  that  where  there  is  a  complex 
of  granite,  gneiss,  and  schists  (as  in  many  of  the  mountain  ranges), 
precisely  like  that  found  elsewhere  in  the  West,  and  known  to  be  pre- 
Oambrian,  the  lithological  evidence  for  reference  to  the  Archean  is  suf- 
ficient. Among  such  ranges  are  the  Oortez,  Shoshone,  Havallah,  East 
and  West  Humboldt,  Montezuma,  Pah-tson,  Truckee,  Pea  Vine,  and 
others. 
The  question  as  to  the  separability  of  the  rocks  referred  to  the  Ar- 
chean into  two  series  is  hardly  touched.  In  the  East  Humboldt  it  is 
evidently  thought  that  the  White  Cloud  peak  granite  is  older  than  the 
schistose  series,  the  former  being  regarded  as  Huronian  and  the  latter 
apparently  as  post-Huronian.  One  wishes  that  more  evidence  were 
given  that  the  granite  mass  in  this  case  does  not  cut  the  schists  and 
gneisses  as  in  most  of  the  other  ranges.  This  is  especially  true  because 
Hague  says  the  White  Cloud  mass  has  the  characteristics  of  an  erup- 
tive rock.  More  often  the  granites  cut  the  overlying  schists,  as  in  the 
Shoshone,  Havallah,  West  Humboldt,  Montezuma  and  Pah-tson  ranges, 
so  that  all  of  the  rocks  referred  to  the  Archean  are  in  these  ranges 
basement  complexes. 
Whether  there  is  in  any  of  the  northern  Nevada  ranges  genuine 
elastics  which  are  placed  among  the  Archean  is  not  positively  deter- 
mined. The  quartz- schists,  limestones,  and  mica-schists  of  the  Hum- 
boldt range  seem  to  be  such  a  series,  although  they  have  now  become 
very  crystalline  by  dynamic  action.  In  the  West  Humboldt  range  in 
the  schists  are  mentioned  fragment-like  areas  of  quartz,  which  are 
explained  to  be  aggregations  formed  by  metamorphism.  In  the  Pea 
Vine  range  there  are  quartzites.  While  from  the  descriptions  there 
is  no  definite  indication  that  truly  clastic  series  exist  elsewhere, 
such  may  hopefully  be  searched  for  in  the  Peoquob,  Shoshone,  West 
Humboldt,  Montezuma,  Pah-tson,  Truckee,  with  perhaps  a  greater 
probability  of  success  in  the  Shoshone,  Peoquob,  and  Truckee. 
If  the  lower  10,000  or  12,000  feet  of  quartzite  in  the  Wasatch  below 
the  lowest  fossiliferous  horizon  belong  with  the  pre-Cambrian  rocks,  as 
suggested  in  the  previous  section,  it  is  probable  that  parts  of  the 
quartzites  below  the  Primordial  fauna  in  Schell  creek,  Egan,  Pogonip, 
and  Piiion  ranges  belong  in  the  same  series — that  is,  the  Upper  Al- 
gonkian. 
It  is  possible  that  several  of  the  quartzites  referred  to  the  Ogden 
and  Weber  belong  much  lower  in  the  geological  column  than  supposed, 
for  it  is  stated  that  in  some  cases  these  are  referred  to  the  Weber  or 
Ogden  for  the  sake  of  convenience,  upon  the  slightest  lithological  evi- 
ience,  or  the  mere  personal  impression  of  the  observer.  Some  of  these 
nay  be  as  low  as  Upper  Algonkian.  The  series  referred  to  the  Weber, 
ivhich  in  its  lithological  character  is  most  similar  to  the  Algonkian,  is 
