NEW    BRUKSWICK,    NOVA    SCOTIA,    NEWFOUNDLAND,    ETC,       507 
magnesian  rocks,  which  are  in  a  vertical  or  highly  inclined  position 
and  evidently  belong  to  a  pre-Carboniferous  altered  sedimentary 
series.  The  junction  of  the  pre-Carboniferous  limestones  with  the 
syenite  is  approximately  parallel  to  the  mountain  range,  but  is  locally 
irregular,  and  in  some  instances  the  limestones  seem  to  fill  depressions 
in  the  syenite.  The  Lower  Carboniferous  rocks  in  places  rest  directly 
upon  the  syenite,  filling  the  hollows  in  it,  and  have  basal  conglomer- 
ates, the  debris  of  which  is  derived  from  the  underlying  syenite, 
limestone,  and  quartzite. 
Fletcher,"'3  in  1877,  finds  in  Cape  Breton,  below  the  Lower  Silu- 
rian rocks  (afterward  found  to  carry  Paradoxides) ,  first,  a  set  of 
syenitic,  gneissoid,  and  felsitic  rocks;  and  second,  the  George  River 
limestone  series,  consisting  of  crystalline  limestones  and  dolomites, 
interstratified  with  felsite,  syenite,  diorite,  mica  schist,  quartzite, 
and  quartzose  conglomerate;  both  of  which  are  referred  to  the  Lau- 
rentian,  although  the  latter  may  be  Huronian.  The  Lower  Silurian 
shales  lie  nearly  horizontally  upon  the  syenites  and  felsites,  without 
any  appearance  of  alteration  and  without  being  intruded  by  the  fel- 
sites or  syenites.  The  crystalline  limestone  series  is  in  close  affinity 
with  the  feldspathic  group  of  rocks,  but  is  distinct,  as  is  shown  by  the 
occurrence  of  pebbles  of  syenite  and  felsite  in  the  quartzose  conglom- 
erate of  Murphy  Brook. 
Fletcher,51  in  1878,  continues  his  study  of  the  pre-Cambrian  of 
Cape  Breton  and  northern  Nova  Scotia.  The  George  River  limestone 
is  bounded  on  both  sides  by  coarse  syenitic  and  granitic  rocks  and  is 
in  apparent  unconformity  with  them. 
Dawson  (Sir  William),55  in  1878,  places  the  rocks  of  the  Boisdale 
Hills  in  Cape  Breton  as  older  than  the  Lower  Silurian,  and  it  is  not 
impossible  that  rocks  of  the  same  age  may  occur  in  the  vicinity  of  the 
Cambrian  beds  at  Mira.  Also  the  chloritic  rocks  of  Yarmouth  may 
conjecturally  be  placed  with  the  Huronian.  With  the  exception  of 
the  rocks  of  St.  Anns  Mountain,  of  the  island  of  St.  Paul,  and  some 
parts  of  northern  Cape  Breton,  no  rocks  are  found  which  are  re- 
garded as  lithologically  equivalent  to  the  Laurentian  of  Canada. 
Fletcher,50  in  1879,  describes  the  pre-Primordial  rocks  as  occupy- 
ing two  large  areas,  one  constituting  the  Mira  Hills,  while  the  other 
is  a  belt  of  variable  width  along  the  shore  of  the  Atlantic.  There 
are  two  basins  of  metamorphic  rocks  running  parallel  to  the  felsite 
series;  one  of  these  abounds  in  Primordial  fossils,  and  the  second  is 
probably  of  Devonian  age.  The  latter  contains  masses  of  granitoid 
and  trappean  rocks. 
Fletcher,57  in  1881,  in  continuing  his  studies  in  northern  Xova 
Scotia,  again  divides  the  pre-Cambrian  rocks  into  two  groups.  In  the 
first  or  felsitic  group  quartzites  are  also  found  intimately  inter- 
mingled.   The  George  River  limestone  series  is  considered  as  an  un- 
