502  PRE-CAMBRIAN    ROCKS    OF    NORTH    AMERICA.  [bull.  86. 
to  be  the  elastic  series  in  a  more  metamorphosed  condition.  In  this 
region  it  is  probable  that  the  fundamental  complex  does  not  appear, 
the  lowest  series  found  being  a  clastic  one  which  is  to  be  placed  in 
the  Algonkian.  The  lithological  character  of  the  Lower  Algonkian 
crystalline  series  more  nearly  resembles  the  Upper  Laurentian  of  the 
original  Laurentian  area  than  any  other.  The  unmetamorphosed  slate 
and  quartzite  series  unconformably  above  it  can  not  now  safely  be  cor- 
related with  any  of  the  clastic  series  to  the  west.  It  may  be  that  it  is 
Upper  Huronian  or  later. 
SOUTHERN  NEW   BRUNSWICK. 
In  southern  New  Brunswick,  while  the  geology  is  exceedingly  com- 
plicated, and  the  later  conclusions  of  the  official  geologists  differ  funda- 
mentally from  those  earlier  held,  it  is  plain  that  there  exists  here  a  pre- 
Cambrian  clastic  series  of  great  thickness.  The  wholly  crystalline  gran- 
ites, gneisses,  etc.,  at  the  base,  in  their  general  lithological  descriptiod 
resemble  the  Archean  of  the  West,  but  from  present  evidence  it  is  im- 
possible to  decide  whether  these  are  subsequent  intrusives,  the  prod- 
uct of  complete  metamorphism  of  the  clastic  series,  or  are  a  basement 
complex.  The  geologists  who  have  described  the  region  clearly  main- 
tain that  this  series  is  more  ancient  than  the  oldest  associated  elastics, 
although  the  relations  strongly  suggest  the  possibility  of  an  eruptive 
contact  between  the  latter  and  the  granites  and  gneisses.  The  older 
series  of  elastics,  called  the  Upper  Laurentian,  does  not  have  a  great 
thickness,  consists  of  quartzites,  slates,  and  crystalline  limestone  inl 
terstratified  with  argillites,  slate- conglomerates,  and  gneisses.  This 
series  in  its  lithological  character  is  like  the  original  Upper  Lauren- 
tian. Above  it,  conforming  with  this  series  and  the  granites  and' 
gneisses,  is  the  Coldbrook  series,  which  is  very  largely  composed  of  sur- 
face volcanic  flows  and  elastics.  Above  this  are  the  Coastal  and  King- 
ston series,  which  are  wholly  unmetamorphosed  clastic  rocks,  associated 
with  contemporaneous  eruptives.  Between  the  two  is  something  of  an 
unconformity,  but  it  is  not  thought  by  the  New  Brunswick  geologists 
to  have  marked  a  considerable  epoch  of  time.  The  two  upper  series  canj 
not  certainly  be  correlated  with  series  in  other  parts  of  Canada  and 
about  lake  Superior,  but  not  improbably  they  belong  above  the  horizon 
of  the  Lower  Huronian,  being  perhaps  equivalent  to  the  Upper  Huro- 
nian or  Keweenawan,  or  with  the  erosion  intervals  which  separate  these 
series. 
NOVA   SCOTIA  AND   CAPE   BRETON. 
In  Cape  Breton  the  relations  between  the  basal  complex  and  the 
George  river  limestone  series  are  identical  with  those  between  the  basal 
complex  and  the  so-called  Upper  Laurentian  of  southern  New  Brunswick; 
i.  e.,  there  is  here  a  clastic  series  and  a  granitoid  gneiss  series  in  which 
it  is  impossible  to  say  definitely  whether  the  relations  are  those  caused 
