itanhise.J  EASTERN    CANADA   AND    NEWFOUNDLAND.  2'di 
that  many  of  the  supposed  conclusions  reached  in  the  early  reports  are 
?pen  to  doubt.  The  most  noticeable  feature  is  the  failure  to  subdivide 
bhe  Huronian  into  two  or  three  series  on  these  maps  when  the  divisions 
Doldbrook,  Coastal,  and  Kingston  have  been  found  in  the  reports  for 
many  years.  The  reason  assigned  on  the  maps  for  this  is  that  the  three 
series  are  so  intimately  intermixed  that  their  separation  with  any  ap- 
proach to  accuracy  is  impossible. 
The  difficulty  of  the  geology  of  this  region  is  shown  by  the  manner 
in  which  these  groups  have  been  shifted  from  one  place  to  another.  In 
bhe  days  of  the  earlier  work  none  of  them  were  regarded  as  pre-Cam- 
brian, and  a  portion  was  given  as  high  a  place  as  the  Devonian.  The 
Kingston  group  in  1865  was  called  upper  Silurian  and  was  regarded  as 
overlying  the  St.  John ;  in  1872  was  called  upper  Huronian ;  in  1876 
was  again  placed  as  Silurian;  and  was  not  until  1879  finally  placed 
with  the  upper  Huronian.  The  Coastal  group,  first  placed  in  the  fos 
siliferous  series,  in  1872  was  placed  in  the  middle  Huronian;  in  1878 
was  doubtfully  referred  to  the  Laurentian,  and  in  1879  was  again  re- 
burned  to  its  place  as  middle  Huronian.  The  Coldbrook  group  has 
been  reckoned  as  Huronian  since  1865. 
At  the  outset,  in  discussing  the  results  attained  as  to  the  succession 
Df  crystalline  rocks,  the  intrusive  character  of  a  very  large  part  of  the 
granite  at  a  period  later  than  pre-Cambrian  time  may  be  considered  as 
demonstrated.  To  this  conclusion  all  the  official  geologists  have  agreed 
with  the  exception  of  Hind,  whose  work  was  done  at  a  time  in  Which 
the  metamorphic  theory  had  extreme  power.  Anneainced  by  Gesner  in 
1841,  the  evidence  cited  by  him  for  the  intrusive  character  of  the  gran- 
ite is  in  a  measure  the  same  as  that  so  convincingly  given  by  Bailey 
over  forty  years  later,  in  1884. 
I  The  plainly  eruptive  character  of  a  part  of  the  granite  suggests  the 
Question  as  to  whether  the  great  mass  of  syenite,  granite,  and  gneiss 
making  up  the  lower  Laurentian  is  not  also  of  an  igneous  character. 
(Even  if  this  be  so,  it  does  not  follow  that  it  is  not  the  most  ancient  rock 
in  southern  New  Brunswick;  but  the  possibility  is  suggested  that  it 
nay  be  an  intrusive  of  a  much  earlier  age  than  those  which  cut  the 
|ilurian  strata,  and  yet  not  be  earlier  than  a  portion  of  the  crystalline 
:ocks  of  clastic  origin  and  pre-Cambrian  age. 
1  It  is  evident  that  among  the  rocks  referred  to  the  Laurentian  of 
outhern  New  Brunswick  is  a  great  series  of  completely  crystalline 
ocks,  and  an  apparently  unimportant  series  composed  of  slates,  quartz  - 
s,  and  limestones.  This  is  shown  by  the  estimated  thicknesses  given 
n  the  report  published  in  1872.  The  lower  Laurentian  is  given  a 
hickness  of  over  13,000  feet,  while  the  upper  Laurentian  (elastics)  have 
|  thickness  not  to  exceed  1,000  feet. 
The  suggested  intrusive  character  of  the  lower  Laurentian  is  made 
lore  probable  by  the  fact  that  there  is  said  to  be  transitions  between 
jhese  plainly  clastic  rocks  and  the  thoroughly  crystalline  ones.    Upon 
