504  PKE-CAMBKIAN    GEOLOGY   OF    NORTH   AMERICA. 
position.  This  granite  is  the  only  Primitive  rock  of  Nova  Scotia. 
The  line  of  junction  between  the  slate  and  granite  was  not  observed. 
The  slates  are  cut  by  numerous  dikes  believed  to  be  of  igneous  origin. 
Brown,44  in  1843,  places  the  whole  northern  part  of  Cape  Breton 
in  the  Primary  rocks.  Cape  North  is  composed  of  mica  slate,  gneiss, 
and  granitic  rocks  apparently  interstratified,  with  an  east-west  strike 
and  upturned  nearly  on  edge.  Igneous  rocks  occupy  a  large  part  of 
the  island.  These  protrude  through  the  limestones  and  graywackes 
which  are  associated  with  the  coal  measures. 
Dawson  (Sir  William),45  in  1850,  divides  the  metamorphic  rocks 
of  eastern  Nova  Scotia  into  two  groups,  one  along  the  Atlantic  coast 
and  vicinity,  and  another  belt  to  the  west,  parallel  to  the  first.  The 
coast  group  consists  of  quartzites,  mica  slates,  and  clay  slates,  which 
are  cut  by  granites,  and  it  is  therefore  called  the  granitic  group  of 
metamorphics.  The  second  group,  the  slates  and  quartzites,  include 
micaceous  and  talcose  schists,  while  the  intrusive  rocks  are  syenites, 
and  the  group  is  therefore  called  the  syenitic  group.  The  syenitic 
group  rests  unconformably  below  the  carboniferous  rocks,  the  latter 
containing  fragments  from  the  former.  These  are  seen  at  numerous 
points.  Both  of  these  groups  of  rocks  are  regarded  as  belonging  to 
the  fossiliferous  series,  the  syenitic  group  being  Silurian.  The  gran- 
itic group  is  probably  older  than  the  syenitic,  and  therefore  also  Silu- 
rian or  pre-Silurian,  but  the  actual  superposition  of  the  beds  of  the 
two  groups  was  not  observed. 
Dawson  (Sir  William),40  in  1855  and  1808,  places  in  the  Upper 
Silurian  large  areas  in  the  northern  and  eastern  parts  of  Cape  Breton, 
as  well  as  other  smaller  areas,  and  large  areas  in  northern  Nova  Scotia 
and  in  southern  Nova  Scotia  northwest  of  the  gold-bearing  series. 
The  rocks  have  been  subjected  to  great  disturbances  and  are  much 
complicated  in  structure.  They  include  many  varieties — syenite,  por- 
phyry, greenstone  slates,  quartzites,  conglomerates,  and  sandstones. 
Large  areas  of  granitic  rocks  are  also  found  associated  with  the  meta- 
morphic series  referred  to  the  Upper  Silurian. 
The  Lower  Silurian  covers  a  very  large  area  along  the  Atlantic 
coast  of  Nova  Scotia,  known  as  the  gold-bearing  series.  This  area  has 
afforded  no  fossils,  but  appears  to  be  a  continuation  of  Jukes's  older 
slate  series  of  Newfoundland,  which  contains  Paradoxides.  Among 
the  metamorphic  rocks  of  this  region  are  gneiss,  mica  slate,  quartz 
rock  or  quartzite,  and  clay  slate.  The  gneiss  is  unquestionably  the 
product  of  metamorphism  due  to  the  baking  of  sedimentary  rocks 
by  heat  and  water,  while  the  quartzite  consists  of  grains  of  flinty 
sand  fused  together.  The  preponderant  rocks  are  thick  bands  of 
slate  and  quartzite  having  a  general  northeast-southwest  strike  and 
highly  inclined.  Whether  the  mica  schists  and  gneiss  of  Cape  Canso 
and  Queens  and  Shelburne  counties  and  the  chloride  beds  of  Yar- 
