NEW    BRUNSWICK,    NOVA    SCOTIA,    NEWFOUNDLAND,    ETC.      495 
Huronian — Coastal,  Coldbrook,  and  Kingston.  Of  the  relations  of 
the  upper  members  of  the  Laurentian,  mica  schist,  limestone,  and  fine 
gneiss,  to  the  main  body  of  coarse  syenite  and  syenitic  gneiss  constitut- 
ing the  Lower  Laurentian  nothing  further  is  known  than  is  contained 
in  the  report  of  1870-71.  The  greatly  broken  and  disturbed  character 
of  the  supposed  upper  series,  the  obscure  stratification  of  much  of  the 
underlying  group,  and  the  frequent  occurrence  of  intrusive  masses 
combine  to  make  the  determination  difficult.  There  can,  however,  be 
no  question  that  most  of  the  calcareous  and  siliceous  strata  are  more 
recent  than  the  coarse  granitoid  rocks  with  which  they  are  associated. 
With  one  possible  exception  no  instances  of  direct  superposition  of 
the  Coldbrook  rocks  on  the  Laurentian  have  been  observed;  but  the 
Coastal  rocks  are  found  upon  the  Coldbrook  rocks  as  well  as  upon 
the  Upper  Laurentian,  so  there  is  no  reasonable  doubt  as  to  the  true 
succession.  Contacts  of  the  Coastal  group  with  the  Coldbrook  group 
are  found  in  the  county  of  St.  John,  and  especially  along  the  line  of 
the  St.  Martins  and  Upham  Kailway,  between  Upham  and  Quaco,  and 
on  the  lower  Quaco  road  on  either  side  of  Bloomsbury  Mountain.  In 
passing  from  one  to  the  other  there  is  often  an  abrupt  change  of  clip, 
the  beds  of  the  higher  series  dipping  at  a  lower  angle  than  those  upon 
which  they  rest,  while  along  the  same  line  of  contact  it  is  not  uncom- 
mon to  find  masses  of  coarse  breccia  conglomerate,  in  which  the  frag- 
ments are  largely  the  petrosilex  derived  from  the  inferior  group.  It 
is,  however,  questioned  whether  the  unconformity  is  sufficient  to  prove 
the  fact  of  any  considerable  lapse  of  time.  The  age  and  equivalency 
of  the  Kingston  group,  as  well  as  of  the  Mascarene  Peninsula,  are 
somewhat  uncertain,  owing  to  the  difficulty  of  obtaining  stratigraph- 
ical  evidence  and  to  the  close  resemblance  which  many  of  them  bear  on 
the  one  hand  to  the  rocks  of  the  Huronian  and  on  the  other  to  those 
of  the  Silurian. 
Bailey,21  in  1881,  in  summarizing  the  work  of  the  survey  in  New 
Brunswick,  concludes  that  there  are  a  Laurentian  and  a  Huronian, 
as  in  other  parts  of  Canada.  These  are  below  the  Primordial  by  a 
marked  unconformity.  These  rocks  east  of  St.  John  occupy  irregu- 
lar troughs  in  the  pre-Silurian  rocks,  resting  sometimes  upon  one  and 
sometimes  upon  another  of  the  subdivisions  of  the  latter,  crossing 
their  strike  obliquely  and  having  coarse  basal  conglomerates.  There 
is  almost  perfect  lithological  likeness  between  the  great  mass  of 
rocks  referred  to  the  Laurentian,  including  coarse  and  fine  grained 
gneisses,  quartzites,  graphitic  and  serpentinous  greenstones,  and 
dolomites,  and  the  Laurentian  of  other  parts  of  Canada,  and  par- 
ticularly the  Hastings  series  of  Vennor.  This  series  is  capped  by  the 
great  volcanic  series  of  the  Huronian.  These  pre-Silurian  rocks  are 
confined  wholly  to  the  region  of  the  southern  metamorphic  hills, 
nothing  of  equivalent  age  having  yet  been  identified  in  the  central 
