674  PRE-CAMBRIAN    GEOLOGY    OF    NORTH   AMERICA. 
are  followed  by  a  bed  of  conglomeratic  quartzite  and  slates,  upon 
which  lie  unconforniably  the  Primordial  rocks. 
Campbell  (J.  L.),51  in  1880,  describes  the  metamorphic  Archean 
rocks  along  James  River  and  the  Kanawha  Canal  as  including  lime- 
stones, schists,  and  quartzites. 
Campbell  (J.  L.),52  in  1880,  describes  the  Archean  rocks  at  James 
River  Gap  as  consisting  of  granulite  and  syenite,  upon  which  rest 
much  metamorphosed  beds  of  conglomeratic  quartzite,  and  over  these 
slates.  These  Archean  rocks  are  unconforniably  below  the  Primordial 
rocks,  which  contain  fragments  of  slate  and  crystals  of  feldspar, 
epidote,  etc.,  more  or  less  waterworn  and  cemented  together.  The 
slates  were  metamorphosed  before  they  were  deposited  in  the  Primor- 
dial strata.  The  syenite  and  granulite  are  eruptive  rocks  which  have 
been  thrown  up  since  the  deposition  of  the  Primordial,  as  is  indicated 
by  the  fact  that  the  stratified  rocks  dip  at  a  high  angle  away  from  the 
igneous  masses,  and  also  by  the  influence  the  heat  of  the  igneous  rocks 
has  exerted  upon  the  overlying  slates  and  sandstones.  Higher  in 
the  series  traces  are  found  of  metamorphic  changes.  The  syenite  and 
granulite  are  supposed  to  be  the  result  of  aqueo-igneous  fusion  and  to 
represent  material  which  is  really  older  than  the  stratified  rocks. 
Fontaine/'3  in  1883,  describes  the  Blue  Ridge  between  Turks  Gap 
and  Balcony  Falls  as  consisting  of  Laurentian,  Huronian,  and 
Primordial  rocks.  The  first  is  mostly  gneiss;  the  second,  mostly 
hornblendic,  micaceous,  and  argillaceous  schists;  and  in  the  Primor- 
dial is  found  Scolithus. 
Rogers  (W.  B.),54  in  1884,  states  that  the  Blue  Ridge  is  a  continu- 
ation of  the  Green  Mountains  of  Vermont,  the  Highlands  of  New 
York  and  New  Jersey,  and  the  South  Mountain  of  Pennsylvania, 
and,  continued  southward,  becomes  the  Smoky  or  Unaka  Mountains 
of  Tennessee.  The  rocks  consist  for  the  most  part  of  the  older  meta- 
morphic strata,  including  gneiss  and  micaceous,  chloritic,  talcose,  and 
argillaceous  schists,  together  with  masses  referable  to  the  earliest 
Appalachian  formations,  sometimes  in  a  highly  altered  condition. 
Innumerable  dikes  and  veins  of  all  dimensions,  consisting  of  a  vast 
variety  of  igneous  materials,  penetrate  this  belt,  disturbing  and  alter- 
ing its  strata  in  a  remarkable  degree.  Southern  dips  are  prevalent 
throughout  the  wmole  of  the  region.  This  is  particularly  the  case  in 
the  southeastern  or  most  disturbed  side  of  the  belt,  but  on  the  north- 
western side  the  reverse  dips  are  more  common.  In  many  cases  the 
ordinary  anticlinal  and  synclinal  structures  are  regarded  as  over- 
turned in  a  northwest  direction,  which  makes  the  two  sides  of  the  fold 
approximately  parallel,  and  when  this  is  not  the  case  gives  tli3  north- 
western side  a  deeper  dip  than  the  southeastern.  In  many  of  the  sec- 
tions the  unconformity  between  the  Cambrian  and  the  crystalline 
metamorphic  rocks  is  unmistakable,  the  lower  members  of  the  former 
