v      m  ..  ]  EASTERN    CANADA    AND    NEWFOUNDLAND.  24!) 
Lascie  harbor  the  rocks  are  mainly  gneiss,  resting-  uncomformably  upon 
which  is  a  great  mass  of  unstratified  quartzite. 
Murray,69  in  1868,  treats  of  the  peninsula  of  Avalon.  Here  is  found 
a  gneiss  which  is  referred  to  the  Laurentian.  Intermediate  between 
this  gneiss  and  the  Lower  Silurian  strata  is  a  great  thickness  of  slates 
and  quartzites,  which  are  referred  to  the  Huronian.  Besting  uncon- 
formably  upon  these  rocks  are  others  containing  Potsdam  fossils. 
In  the  Laurentian  are  placed  the  gneisses  of  Conception  bay,  the 
masses  of  granite,  syenite,  and  porphyries  of  St.  Johns  peninsula  de- 
scribed by  Jukes,  and  the  granites  of  Placentia  bay  and  Sound  island. 
These  rocks  are  like  those  referred  to  the  Laurentian  in  the  great  north- 
ern peninsula.  The  intermediate  system  consists  of  diorites,  quartzites, 
slate  conglomerates,  slate  and  sandstone,  the  whole  series  in  Concep- 
tion bay  being  over  11,000  feet  thick.  This  series  resembles  lithologi- 
cally  the  Huronian  system  of  Canada  in  a  high  degree,  although  it  may 
be  admitted  that  lithological  relations  are  of  secondary  importance  in 
correlating  rocks  which  are  remote  from  each  other.  In  one  member  of 
the  group  is  a  fossil,  designated  as  Aspidella,  of  alow  order  of  existence, 
which  leads  to  the  conclusion  that  the  system  is  probably  Cambrian.  This 
series  of  rocks  occupies  by  far  the  greater  x^art  of  the  peninsula  of  Ava- 
lon. The  lower  rocks  in  all  cases  pitch  at  a  very  high  angle  to  the  hori 
zon,  the  prevailing  inclination  being  to  the  eastward,  while  the  upper 
formation,  except  where  disturbed  by  eruptives,  is  either  in  a  perfectly 
horizontal  attitude  or  only  slightly  inclined.  The  lower  series  is  also 
marked  for  its  general  absence  of  lime,  while  the  upper  formation  is 
nearly  all  more  or  less  calcareous.  Further,  the  Potsdam  rocks  were 
found  to  overlie  iincomformably  the  lower  slates  at  Manuels  brook  and 
at  Brigus  South  Head.  The  Nova  Scotia  gold-bearing  rocks  are  litho 
logically  like  the  system  referred  to  the  Huronian  in  Newfoundland, 
although  they  have  been  referred  to  the  Lower  Silurian. 
Murray,70  in  1870,  finds  the  rocks  of  Bonavistabay  to  consist  largely 
of  slates,  slate-conglomerates,  quartzites,  and  diorites,  intersected  by 
intrusive  granite  or  syenite,  trap,  and  quartz  veins.  This  series  has 
such  a  close  lithological  resemblance  to  the  intermediate  system  of 
Avalon  that  there  is  no  doubt  of  their  identity.  These  rocks  also  occur 
between  the  gneiss  and  the  Paleozoic  formations  of  Trinity  bay. 
Howley/1  in  1870,  describes  sundry  parts  of  the  coast.  The  rocks 
of  cape  Ray  and  the  extreme  head  of  Conception  bay  are  of  a  gneissoid 
character.  Granite,  syenite  and  trap  are  interbanded  with  quartzite. 
Upon  Great  Miquelon  island  is  found  gneiss,  supposed  to  be  of  Lauren- 
tian age.  Greenstones  and  granite  break  at  various  places  through  the 
stratified  rocks. 
Murray,72  in  1873,  gives  a  further  account  of  the  Avalon  peninsula. 
The  line  of  contact  between  the  Huronian  and  more  recent  rocks  in 
Trinity  bay  is  obscure  and  difficult  to  detect,  and  here  Aspidella  is  very 
useful  in  deciding  to  which  series  the  rocks  belong.     The  rocks  on  the 
