512  PRE-CAMBKIAN    GEOLOGY    OF    NORTH   AMERICA. 
conglomerates,  quartzites,  clay  slates,  mica  slates,  and  mica  schists. 
The  lower  15,840  feet  are  chiefly  quartzite,  and  the  upper  10,560  feet 
are  a  graphitic  and  ferruginous  slate.  These  sedimentary  rocks  are 
intruded  by  great  masses  of  granite,  and  adjacent  to  them,  and 
due  to  their  metamorphic  influence,  are  the  mica  slates  and  mica 
schists.  The  slates  and  quartzites  are  folded  into  sharp  undulations 
and  are  cut  by  a  regional  slaty  cleavage.  In  the  more  disturbed  parts 
of  the  area  the  bedding  is  not  easily  recognized. 
The  slates  and  quartzites,  the  "  gold-bearing  series,"  are  not  found 
in  such  structural  relations  with  the  early  fossiliferous  rocks  as  make 
a  satisfactory  correlation  possible.  Dawson,  in  1850,  places  them  as 
"  Lower  Silurian  "  or  pre-Silurian.  Later,  in  his  Acadian  Geology, 
they  are  classified  as  "  Lower  Silurian,"  although  it  is  stated  that  no 
fossils  are  found  in  them.  Faribault  subsequently  called  them 
"  Lower  Cambrian,"  citing  as  evidence  the  presence  of  the  obscure 
fossil  Eophyton,  discovered  by  Selwyn.  Dawson  found  no  fossil  evi- 
dence for  his  reference  of  this  series  to  the  "  Lower  Silurian;"  and  it 
is  remarked  by  Silliman  that  immediately  overlying  rocks  contain- 
ing fossils  have  never  been  found.  Although  Hind  in  1870  says  that 
the  fossiliferous  "  Upper  Silurian  "  conformably  overlies  the  gold- 
bearing  series,  this  statement  has  been  found  nowhere  else,  and  later 
observers  have  not  repeated  it,  so  that  it  may  be  considered  very 
doubtful.  Although  no  well-defined  fossils  have  been  found,  Fari- 
bault now  believes  the  gold-bearing  sediments  to  be  Cambrian,  be- 
cause of  their  analogy  with  the  Harleck  grit  and  Lingula  flag  series 
of  North  Wales,  the  auriferous  Cambrian  of  Quebec,  and  Murray's 
Intermediate  series  of  Newfoundland.  Finally,  Woodman,  after  a 
careful  sifting  of  evidence,  has  concluded  that  the  series  is  pre-Cam- 
brian. 
Hence,  so  far  as  definite  knowledge  is  concerned,  the  gold-bearing 
series  may  be  as  late  as  Cambrian ;  but  it  is  believed  that  the  proba- 
bility is  strongly  in  favor  of  their  Algonkian  age.  Bearing  in  this 
direction  is  the  abundance  of  fossils  in  the  lower  Cambrian  of  south- 
ern New  Brunswick  and  Cape  Breton  and  in  the  lower  Cambrian  of 
Newfoundland  to  the  northeast.  The  extreme  scarcity  of  fossils  in 
the  rocks  in  question  renders  it  probable  that  they  are  older  than  the 
fossil-bearing  Cambrian  rocks  of  the  same  region.  They  are  much 
thicker  than  the  known  Cambrian  rocks  of  New  Brunswick  and 
Newfoundland.  Also  in  Newfoundland  the  lower  Cambrian  rocks 
rest  unconformably  upon  a  great  series  of  slates  and  quartzites,  in 
most  respects  similar  to  the  gold-bearing  series  of  Nova  Scotia.  In 
Newfoundland  these  are  certainly  Algonkian,  and  it  seems  highly 
probable  that  the  similar  rocks  in  Nova  Scotia  were  deposited  at  the 
same  time,  the  two  districts  being  parts  of  the  same  geological 
province.     Woodman  cites  also  the  magnitude  of  the  unconformity  at 
