SUMMARY   OF    GENERAL   LITERATURE.  97 
Part  II  is  a  resume  of  knowledge  to  date  on  pre- Cambrian  regions 
of  North  America,  with  a  general  discussion  of  the  nature  and  cor- 
relation of  the  pre- Cambrian  series.  As  the  present  bulletin  is  essen- 
tially a  revision  and  amplification  of  this  resume,  this  part  of  Van 
Hise's  principles  will  not  be  here  summarized. 
Ells,29  in  1897,  gives  a  general  account  of  the  Archean  of  eastern 
Canada,  including  a  review  of  the  various  classifications  made  by  the 
earlier  geologists,  and  their  recent  modifications.  It  is  concluded 
that  it  is  possible  to  reduce  the  great  series  of  the  so-called  Laurentian 
rocks  to  two  principal  divisions,  viz,  a  lower  Basal  or  Fundamental 
gneiss,  in  which  all  traces  of  sedimentation  are  wanting,  and  which 
may  be  regarded  as  representing  in  altered  form  some  portion  of  the 
original  crust  of  the  earth;  and  a  newer,  secondary  series,  derived 
doubtless  from  the  decay  of  the  former,  in  which  the  evidences  of 
clastic  origin  are  manifest.  On  this  basis  the  arrangement  of  the  sys- 
tems for  eastern  Canada  would  be  as  follows : 
Laurentian,  nonsedimentary : 
Basal  or  Fundamental  gneiss  (Ottawa  gneiss),  representing  in  altered  form 
the  original  crust  of  the  earth,  and  the  lowest  known  series  of  rocks; 
without  evidence  of  sedimentary  origin. 
Huronian,  partly  sedimentary  and  partly  igneous: 
Grenville  and  Hastings  series,  comprising  limestones,  quartzites,  gneisses, 
etc.,  of  Ontario  and  Quebec,  in  the  Ottawa  district. 
Schists  and  altered   slates,    chloritic   and  other   crystalline   rocks   of   the 
Eastern  Townships  of  Quebec  and  the  Gaspe  Peninsula. 
Felsitic  and  gneissic  rocks  of  northern  New  Brunswick. 
Gneiss,  quartzite,  and  limestone,  of  the  so-called  Laurentian  of  southern 
New    Brunswick,    regarded    as    the    equivalents    of    the    Grenville    and 
Hastings  series,  felsites  and  schistose  rocks  of  the  Coldbrook,  Kingston, 
and  Coastal  divisions,  the  apparent  equivalents  of  the  rocks  of  the  Sutton 
Mountain  anticlinal. 
Felsitic  and  syenite  rocks  of  eastern  Nova  Scotia  and  northern  Cape  Breton, 
with  their  associated  crystalline  limestones  and  serpentines. 
Cambrian : 
Cambrian  slates,  sandstones,  and  conglomerates. 
Dawson,30  in  1897,  gives  a  general  account  of  the  pre-Cambrian 
rocks  of  Canada.  This  is  largely  a  discussion  of  pre-Cambrian  classi- 
fication and  nomenclature,  based  on  a  review  of  early  and  recent  work 
on  the  pre-Cambrian  of  Canada,  and  will,  therefore,  not  be  fully  sum- 
marized. A  few  of  the  more  important  conclusions  may,  however,  be 
mentioned. 
The  Laurentian  still  includes  both  Fundamental  gneiss  and  the 
Grenville  series. 
The  Huronian  proper,  under  whatever  local  name  it  may  be  classed, 
still  remains  a  readily  separable  series  of  rocks. 
The  Upper  Laurentian,  Labradorian,  Norian,  or  anorthosite  group 
is  found  to  consist  essentially  of  intrusive  rocks,  later  in  age  than  the 
Grenville,  but  in  all  probability  pre- Paleozoic. 
55721— Bull.  360—09 7 
