NEW    BRUNSWICK,    NOVA    SCOTIA,    NEWFOUNDLAND,    ETC.       513 
the  base  of  the  Ordovician,  the  great  folding  and  veining  suffered  by 
the  gold-bearing  slates  and  not  by  the  Ordovician,  and  finally  dif- 
ference in  character  of  intrusives. 
Dawson  is  uncertain  whether  the  more  crystalline  mica  schists 
and  gneisses,  which  have  a  somewhat  widespread  occurrence  in  south- 
ern Nova  Scotia,  are  to  be  regarded  as  older  than  the  gold-bearing 
slates.  Hind,  in  1870,  maintained  that  a  set  of  older  schists  and 
gneisses  lie  unconformably  below  the  slates  on  the  Halifax  and  Wind- 
sor  Railway;  and  further,  that  this  set  of  schists  and  gneisses  is 
unconformably  above  another  series  which  he  referred  to  the  "  Lauren- 
tian."  As  no  subsequent  observer  has  mentioned  the  first  of  these 
unconformities,  and  as  it  occurs  at  so  readily  accessible  a  place,  it 
may  well  be  considered  doubtful  whether  the  facts  were  rightly  in- 
terpreted. As  suggested  by  Faribault,  it  does  not  appear  at  all  im- 
probable that  the  gneisses  associated  with  the  gold-bearing  slates  are 
due  to  dynamic  and  contact  metamorphism  of  the  intruding  granite. 
The  coarsely  crystalline  rocks  which  Hind  referred  to  the  Laurentian 
are  certainly  the  series  which  Dawson  and  other  observers  regard  as 
later  granitic  eruptions,  and  the  unconformity  mentioned  is  perhaps 
an  eruptive   unconformity. 
NORTHWESTERN   NOVA   SCOTIA. 
In  northwestern  Nova  Scotia  and  Cape  Breton  is  the  following 
ascending  succession,  as  given  by  Fletcher:  (1)  Syenites,  gneisses, 
felsites,  and  quartzites;- (2)  George  River  series,  consisting  of  crys- 
talline limestone  interstratified  with  mica  schist,  quartzite,  conglom- 
erates, felsite,  syenite,  and  diorite.  By  Fletcher  and  by  Gilpin  the 
George  River  "  series  "  is  regarded  as  resting  unconformably  upon  the 
lower  rocks.  From  the  description  it  is  clear  that  some  of  the  sye- 
nites and  other  massive  rocks  intrude  the  sedimentaries,  but  whether 
any  older  rocks  than  those  of  sedimentary  origin  are  to  be  found 
in  the  region  is  undetermined.  The  Algonkian  may  be  represented 
by  the  elastics,  and  the  Archean  is  doubtfully  present.  Some  of  the 
granites  may  be  even  Paleozoic. 
The  Etcheminian  group  of  this  district,  at  first  described  by  Mat- 
thew as  pre-Cambrian,  was  later  found  by  him  to  contain  Cambrian 
fauna.  The  volcanics  into  which  the  group  grades  below  (correlated 
with  the  Coldbrook  of  New  Brunswick)  contain  slates  with  Cam- 
brian fossils,  and  hence  this  group  of  volcanics,  with  the  Etchemin- 
ian, is  classed  as  Cambrian. 
Hartley,  in  1870,  suggests  the  Laurentian  age  of  the  crystalline 
limestones  and  syenite  of  St.  Amo's,  Cape  Breton.  With  commend- 
able caution  Robb,  in  1876,  only  says  of  this  older  -cries  that  it  is 
pre-Carboniferous.     Later,  Fletcher,  on  lithological   ground-,  corre 
55721— Bull.  360—09 33 
