vanhise.]  THE    GREAT    NORTHERN    AREA.  215 
tlie  entrance  of  the  north  arm  westward  as  consisting  mainly  of  gneiss, 
porphyry,  and  granite.  The  large  islands  and  promontory  of  the  east- 
ern part  of  the  lake  are  of  the  trap  formation.  These  are  compared  to 
the  Coppermine  series.  Pebbles  of  jasper  conglomerate  were  collected 
near  the  west  end  of  the  lake,  but  the  rock  was  not  seen  in  place.  The 
rocks  on  the  route  from  Great  Slave  lake  northeastward  by  Clinton- 
Golden  and  Aylmer  lakes  and  the  Great  Fish  river  to  the  Arctic  coasts 
are  different  varieties  of  granite  and  gneiss. 
Back,22  in  1838,  describes  granite  as  occurring  in  two  places  along 
the  southeastern  coast  of  Southampton  island. 
Simpson,23  in  1843,  applies  the  name  Trap  Point  to  the  Kent  penin- 
sula. After  an  interval  of  low  ground  to  the  eastward  granite  forms 
the  coast  line. 
Rae,24  in  1850,  finds  north  of  latitude  61°  on  the  west  coast  of  Hud- 
son bay,  beyond  NevilFs  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,  hornblende-slate.  Precipitous 
cliffs  of  trap  were  found  on  Simpson  bay,  in  latitude  08°  27'. 
Richardson,25  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  clift's  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  geolog- 
ical 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  the  Coppermine  river,  are  series  of  basaltic  cliffs. 
Sutherland,26  in  1853,  describes  the  rocks  at  cape  York  and  cape 
Atholl,  latitude  76°,  as  consisting  of  sandstones,  interstratified  with 
volcanic  material.  On  the  east  coast  of  Baffin  land,  from  Lancaster 
sound  to  Cumberland  sound,  are  crystalline  rocks  which  occupy  the 
whole  coast  southward  to  Cumberland  strait. 
Murchison,27  in  1857,  states  that  cape  Granite  in  the  Arctic  Archi- 
pelago is  composed  of  quartz,  feldspar,  and  chlorite,  and  is  accompa- 
nied with  gneiss  of  the  same  comx>osition. 
Kane,28  in  1857,  states  that  the  rocks  of  the  coast  between  Rensse- 
laer harbor  and  the  great  Humboldt  glacier  (in  Peabody  bay),  are  strat- 
ified limestones,  sandstones,  feldspathic  and  porphyritic  granite  pass- 
ing into  gneiss,  and  in  some  places  trap. 
Haughton,29  in  1857,  describes  granitic  rocks  as  composinga  consid- 
erable part  of  Eorth  Greenland,  on  the  north  side  of  Baffin  bay,  and 
