CHAPTER  II. 
SUMMARY  OF  LITERATURE  FOR  NORTH  AMERICA 
( GENERAL). « 
Maclure,1  h  in  1809,  places  in  the  Primitive  rocks  granite,  gneiss, 
mica  slate,  clay  slate,  primitive  limestone,  primitive  trap,  serpentine, 
porphyry,  syenite,  topaz  rock,  quartz  rock,  primitive  flinty  slate, 
primitive  gypsum,  and  white  stone ;  and  in  the  Transition,  transition 
limestone,  transition  trap,  graywacke,  transition  flinty  slate,  and 
transition  gypsum.  The  rocks  of  the  Primitive  prevail  east  of  Hud- 
son River.  Throughout  the  greater  part  of  the  eastern  and  northern 
States  the  sea  washes  the  Primitive  rocks,  but  to  the  southwest  the 
Primitive  runs  in  a  broad  belt  as  far  as  Alabama,  and  between  it  and 
the  ocean  is  a  wide  belt  of  alluvial  rocks.  The  Transition  rocks  occur 
in  one  main  belt,  running  in  a  northeast-southwest  direction  from 
New  York  to  Alabama,  and  in  several  minor  belts. 
Eaton,2  in  1832,  places  as  Primitive  rocks  granite,  mica  slate,  horn- 
blende rock,  talcose  rock,  granular  quartz,  and  granular  lime  rock. 
These  Primitive  rocks  are  all  contemporaneous  except  the  granular 
quartz  and  lime  rocks,  since  they  alternate  continually,  and  all  are 
destitute  of  organized  remains.  Numerous  localities  are  given  for 
each  class. 
Emmons  (E.),3  in  1855,  divides  rocks  into  Pyrocrystalline,  Pyro- 
plastic,  and  Hydroplastic. 
The  Pyrocrystalline  class  comprises  massive  rocks,  including 
granite,  syenite,  hypersthene,  pyrocrystalline  limestone,  serpentine, 
rensselaerite,  and  octahedral  iron  ore,  and  laminated  rocks,  including 
gneiss,  mica  slate,  hornblende,  talcose  slate,  etc.,  laminated  limestone, 
and  laminated  serpentine.  The  Pyroplastic  rocks  comprise  subaerial, 
including  lavas  and  tuffs,  or  volcanic  products,  and  submarine,  in- 
cluding greenstone,  porphyry,  basalt,  and  trap.  The  Hydroplastic 
rocks  comprise  Paleozoic,  Mes:>zoic,  and  Cenozoic.  The  Paleozoic  is 
divided  from  the  base  upward  into  Taconic,  Silurian,  Devonian, 
Carboniferous,  and  Permian.     Metamorphic  or  Azoic  rocks  are  not 
« This  chapter  contains  only  such  material  as  can  not  be  easily  classified  under  the 
geographic  headings  of  the  following  chapters.  Many  articles  with  references  to  the 
general  geology  of  North  America  have  been  classed  under  the  local  headings. 
6  For  notes  see  end  of  chapter,  p.  104. 
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