528  PRE-CAMBRIAN    GEOLOGY   OF    NORTH   AMERICA. 
Back,12  in  183b,  describes  granite  as  occurring  in  two  places  along 
the  southeastern  coast  of  Southampton  Island. 
Bayfield,13  in  1810,  describes  granite  rocks  as  occupying  the  fol- 
lowing districts:  Along  the  St.  Lawrence  from  the  Saguenay  to 
Pointe  de  Monts,  a  distance  of  130  miles;  from  Pointe  de  Monts  to 
the  Seven  Islands,  a  distance  of  60  miles;  the  mainland  to  the  east  of 
Mingan  Islands  and  opposite  Ste.  Genevieve  Island,  where  the 
country  for  many  miles  inland  is  composed  of  low  granite  mounds; 
the  coast  from  Ste.  Genevieve  east  to  Cape  Whittle,  longitude  00°  W., 
latitude  50°  10'  N.  The  granites  are  in  part  hornblenclic  and  in  part 
nonhornblendic.  At  Ste.  Genevieve  was  observed  hypersthene  and 
Labrador  feldspar.  The  granitic  rocks  are  regarded  as  unstratified. 
They  are  traversed  by  trap  veins,  insignificant  in  size  as  compared 
with  the  immense  size  of  the  Lake  Superior  granite  masses.  Repos- 
ing horizontally  on  the  granites  on  the  east  side  of  Pillage  Bay  and 
Mount  Ste.  Genevieve  are  limestones.  The  islands  of  the  south  shore 
of  the  St.  Lawrence  and  the  south  coast  from  Saguenay  to  Cape  Rozier 
are  composed  of  alternating  strata  of  graywacke  and  slate  dipping  to 
the  south  at  angles  varying  from  30°  to  90°. 
Simpson,14  in  1843,  applies  the  name  Trap  Point  to  the  Kent  Penin- 
sula. After  an  interval  of  low  ground  to  the  east  granite  forms  the 
coast  line. 
Logan,15  in  1850,  describes  a  metamorphic  group  of  rocks  in  the 
vicinity  of  Bay  St.  Paul,  Murray  Bay,  and  White  Cape  on  St.  Law- 
rence River.  The  predominant  rocks  are  mica  gneisses  and  horn- 
blende gneisses.    No  crystalline  limestones  were  noted. 
Rae,16  in  1850,  finds  north  of  latitude  61°  on  the  west  coast  of  Hud- 
son Bay,  beyond  Nevills  Bay,  the  shore  steep  and  rugged,  being  lined 
with  bare  Primitive  rocks.  On  the  southern  shores  of  the  Gulf  of 
Boothia  granite  occurs  in  several  places,  and  among  the  specimens 
found  are  gneiss,  mica  slate,  quartz  rock,  and  hornblende  slate.  Pre- 
cipitous cliffs  of  trap  were  found  on  Simpson  Bay,  in  latitude  68°  27'. 
Richardson,17  in  1851,  states  that  the  eastern  side  of  the  north  arm 
of  Great  Slave  Lake  is  occupied  by  Primitive  rocks,  which  run  across 
the  outlet  of  Athabasca  Lake  to  the  deep,  northern  arm  of  Great 
Slave  Lake,  and  onward  by  Marten  Lake,  across  the  two  eastern  arms 
of  Great  Bear  Lake,  to  the  Copper  Mountains.  On  Rae  River,  which 
flows  into  Coronation  Gulf  near  the  mouth  of  the  Coppermine,  are 
limestone,  quartz  rock,  and  high  cliffs  of  basalt.  From  the  similarity 
of  the  various  rocks  associated  in  this  quarter  to  those  occurring  at 
Pigeon  River  and  other  parts  of  the  north  shore  of  Lake  Superior 
the  author  is  inclined  to  consider  that  the  two  deposits  belong  to  the 
same  geological  era,  both  being  more  ancient  than  the  Silurian.  At 
Rae  River  and  Richardson  River,  to  the  northwest  of  the  mouth  of  the 
Coppermine,  and  on  the  west  side  of  Coppermine  River  are  series 
of  basaltic  cliffs. 
