vanhise]  EASTERN    CANADA    AND   NEWFOUNDLAND.  243 
first,  or  felsitic  group  quartzites  are  also  found  intimately  intermingled. 
The  George  river  limestone  series  is  considered  as  an  unconformable 
overlying  group  of  pre- Cambrian  age.  The  limestones  in  every  case 
cap  the  felsites,  with,  which,  however,  they  often  seem  to  blend  near 
the  contacts  as  if  by  a  common  metamorphism.  As  evidence  of  this 
unconformity  are  cited  the  occurrences  of  limestone  in  a  higher  position 
than  the  syenites  and  felsites;  the  irregular  line  of  contact  by  which  the 
syenite  passes  under  the  limestone;  and  the  absence  of  veins  and  dikes  of 
syenite  in  the  limestone.  The  rocks  are  sometimes  intricately  mingled, 
as  at  Dallas  brook,  where  layered  felsite,  limestone,  and  slate  are  met 
with,  while  on  the  top  of  the  hill  limestone  occurs,  and  farther  back 
syenite,  displaying  a  coarse  admixture  of  finely  foliated  gneiss.  In  some 
localities  the  syenite  begins  abruptly  as  if  cutting  vein-like  across  the 
strike  of  the  gneiss;  in  others  the  change  from  syenite  to  gneiss  is 
gradual.  The  gneiss  is  associated  with  large  masses  of  white  quartzite. 
Metamorphic  rocks  are  described  which  are  referred  to  the  Devonian, 
but  the  evidence  is  so  slight  that  it  is  concluded  that  all  of  these  strata 
may  belong  to  an  older  period.  Between  them  and  the  pre-Cambrian 
series  there  is  a  marked  unconformity,  and  also  one  of  less  importance 
between  them  and  the  Carboniferous. 
Fletcher,61  in  1885,  finds  that  in  northern  cape  Breton  the  syenitic, 
gneissoid,  and  other  feldspathic  rocks  of  the  Lower  pre-Cambrian  group 
are  intimately  mingled  on  the  Margaree  river  with  foliated  rocks.  At 
Coinneach  brook,  where  the  syenite  comes  in  contact  with  the  contorted 
mica- schist,  the  latter  is  seen  to  underlie  the  syenite.  Higher  up  the 
syenite  again  appears  and  contains  a  layer  5  feet  thick  of  mica-schist 
which  is,  as  it  were,  intruded  among  the  syenites.  Bed  granite  over- 
lies unconformably  the  strata  of  the  George  river  limestone  group  at 
Fionnar  brook. 
Gilpin,62  in  1886,  describes  the  pre-Cambrian  rocks  of  cape  Breton 
as  including  a  felsite  series  and  a  crystalline  limestone  series,  both  of 
which  are  referred  to  the  Laurentian,  and  the  latter  unconformably 
overlying  the  former.  With  the  felsites  and  interstratified  porphyries 
are  also  syenitic  and  gneissic  rocks;  while  the  crystalline  George  river 
limestone  also  contains  interstratified  with  the  limestones,  syenites, 
diorites,  mica- schists,  quartzites,  and  quartzose  conglomerates.  The 
limestone  area  is  limited  in  extent  as  compared  with  the  felsite  group. 
Fletcher,63  in  1887,  further  describes  the  pre  Cambrian  rocks  of  a 
part  of  northern  Nova  Scotia.  The  crystalline  rocks  here  found  resem- 
ble none  known  as  Cambrian  in  other  parts  of  Nova  Scotia,  and  are 
strikingly  like  those  beneath  the  Upper  Cambrian  in  cape  Breton. 
Although  they  are  certainly  known  to  rest  unconformably  below  the 
Cambro- Silurian  strata,  a  part  of  all  of  these  rocks  may  be  Cambrian 
or  even  Cambro- Silurian.  Similar  gneisses  and  schists  in  southern  New 
Biunswick  have  been  included  by  Bailey  in  his  Cambro- Silurian  series. 
Volcanic  rocks,  both  basic  and  acid  and  varying  in  age  from  pre-Cam- 
brian to  Devonian,  or  even  Carboniferous,  are  abundantly  found. 
