AREA   NORTH   AND    NORTHEAST   OF   LAKE    HURON.  425 
granite  near  Onaping,  on  the  Canadian  Pacific  Railway  northwest 
of  Sudbury.  At  the  contact  is  conglomerate  or  breccia  or  pyroclastic 
rock  containing  fragments  of  granite,  greenstone,  slate,  and  quartzite, 
each  of  one  or  more  varieties.  The  fragments  are  both  angular  and 
rounded,  and  sedimentary  material  appears  in  the  matrix.  Resting 
against  the  granite,  and  apparently  under  the  conglomerate  or  breccia, 
is  a  thin  film  of  quartzite  similar  to  that  appearing  as  pebbles  in  the 
conglomerate. 
At  Wahnapitae  they  examined  the  contact  of  the  Laurentian  granite 
with  the  quartzite  of  Bell's  Huronian  series,  and  found  it  to  be  a  case 
of  intricate  intrusion  and  granitization. 
About  half  a  mile  east  of  Sudbury  they  found  a  breccia  or  con- 
glomerate similar  in  every  way  to  that  seen  at  Onaping,  resting  on  the 
eroded  edges  of  Huronian  quartzite  and  containing  fragments  of  it. 
There  is  here  present  also  a  peculiar  tuffaceous  quartzite,  clifferent 
from  the  breccia,  which  probably  is  of  the  same  age  as  the  older 
quartzite.  It  is  believed  that  the  later  tuff  of  this  locality,  together 
with  Bell's  Cambrian,  is  younger  than  both  of  the  clastic  Huronian 
series  of  the  north  shore  of  Lake  Huron. 
The  nickel-bearing  norite  probably  belongs  with  the  upper  series  in 
age.  In  the  vicinity  of  Copper  Cliff  and  the  Murray  mines  the  suc- 
cession seems  to  be:  (1)  Quartzite,  including  both  normal  and  tuffa- 
ceous phases;  (2)  schistose  diorite,  which  is  well  banded  and  locally 
granitized;  (3)  gray  granite;  (4)  norite;  (5)  red  granite. 
In  a  reconnaissance  from  the  train  from  Sudbury  west  to  Cutler, 
77  miles,  quartzite  (Huronian  of  Bell)  was  seen  as  the  predominating 
rock  along  the  railway.  Beyond  Cutler  diorite,  apparently  intrusive 
into  quartzite  and  in  turn  cut  by  red  granite,  appears  in  quantity, 
and  continues  nearly  to  Algoma.  At  Algoma  and  westward  to  Blind 
River,  a  distance  of  7  miles,  the  quartzite  was  again  seen.  From 
Blind  River  the  granite  is  predominant  and  dioritic  schist  is  the 
subordinate  rock  until  Dayton  is  reached,  beyond  which  to  Thessalon 
the  predominating  rock  is  the  dioritic  schist. 
Van  Hise  and  Leith,4t  in  1902,  make  a  somewhat  detailed  study  of 
the  Huronian  area  eastward  from  Sault  Ste.  Marie  to  Thessalon. 
Between  the  "  Soo  "  and  Garden  River  the  "  Lower  slate  conglom- 
erate "  of  Murray  was  found  to  contain  granite,  greenstone,  and  green 
schist  fragments,  the  granite  fragments  being  similar  to  granite  in 
solid  ledges  a  few  paces  to  the  north.  A  short  distance  to  the  east 
what  was  taken  to  be  the  same  conglomerate  was  found  both  north 
and  south  of  the  lower  limestone  in  such  a  position  as  to  suggest  that 
the  structure  is  anticlinal  and  that  the  conglomerates  both  north  and 
south  are  later  than  and  unconformably  above  the  limestone.  If  this 
be  so,  the  conglomerate  mapped  as  lower  slate  conglomerate  by  Logan 
is  really  upper  slate  conglomerate.    To  the  east,  at  the  old  limestone 
