CHAPTER  X. 
ADIRONDACK  MOUNTAINS,  SOUTHEASTERN  NEW 
YORK,  AND  NEW  JERSEY. 
SECTION  1.   ADIRONDACK  MOUNTAINS. 
SUMMARY  OF  LITERATURE. 
Jessup,1  in  1821,  describes  rocks  of  the  Primitive  class,  including 
traj),  syenite,  and  carbonate  of  lime,  in  Essex  County,  in  the  vicinity 
of  Lakes  George  and  Champlain. 
Eaton,-  in  1824,  describes  the  rocks  adjoining  the  Erie  Canal. 
Among  the  Primitive  rocks  are  placed  granite,  gneiss,  hornblende 
rock,  mica  slate,  talcose  rock,  granular  quartz,  granular  lime  rock, 
sparry  lime  rock,  and  Primitive  argillite,  which  are  described  as 
occurring  at  numerous  localities.  There  are  two  Primitive  districts — 
one  in  southeastern  New  York  and  another  west  of  Lake  Champlain, 
called  Macomb  Mountains. 
Emmons  (E.),3  in  1837,  describes  granite  and  gneiss  as  having  a 
widespread  occurrence  in  the  northeastern  part  of  the  State.  The 
granitic  nucleus  of  Essex  County  is  traversed  by  dikes  of  greenstone 
of  igneous  origin,  and  the  granite  is  considered  to  have  the  -nine 
genesis.  Gneiss  and  hornblende  and  granular  limestone  are  classed 
together  as  Primitive  rocks  and  regarded  as  absolutely  of  the  same 
age.  Above  the  Primitive  rocks  is  a  Transition  sandstone,  superim- 
posed upon  which  is  a  Transition  limestone. 
Conrad,4  in  1837,  describes  ridges  of  gneiss  at  the  base  of  the 
Mohawk  Valley  which  are  regarded  as  a  prolongation  of  the  northern 
Primary  chain.     Upon  the  gneiss  is  calcareous  sandstone. 
Emmons  (E.),n  in  1838,  states  that  in  St.  Lawrence  and  Essex 
counties  are  found  Primitive  rocks.  The  stratification  of  the  gneiss 
is  often  obscure  and  its  texture  confusedly  crystalline.  Subordinate 
to  it  and  mingled  with  it  is  granite,  which  occurs  in  beds  and  pro- 
truded masses  in  the  forms  of  veins  and  in  overlying  masses  analogous 
to  lava  currents  and  greenstones.  In  St.  Lawrence  County  is  a  wide- 
spread granite  composed  of  labradorite,  feldspar,  and  hypersthene, 
which  is  traversed  by  dikes  of  greenstone,  amphibolite,  syenite,  and 
porphyry.  Associated  with  the  gneiss  and  limestone  are  numerous 
beds  of  magnetite  and  hematite.  The  Transition  rock-  of  Essex 
County,  such  as  limestones  and  shales,  are  cut  by  dikes  and    vein.-. 
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