﻿28 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  groups, 
  with 
  local 
  variations 
  ranging 
  through 
  both. 
  Its 
  intrusive 
  

   nature 
  is 
  evidenced 
  by 
  the 
  penetration 
  and 
  absorption 
  of 
  an 
  older 
  

   formation, 
  a 
  hornblende 
  schist 
  which 
  occupies 
  limited 
  belts 
  in 
  the 
  

   vicinity, 
  as 
  well 
  as 
  by 
  its 
  pegmatitic 
  and 
  thoroughly 
  massive 
  phases. 
  

  

  The 
  numerous 
  deposits 
  centering 
  around 
  Arnold 
  hill 
  and 
  Palmer 
  

   hill, 
  in 
  southern 
  Clinton 
  county, 
  are 
  inclosed 
  by 
  the 
  same 
  Saranac 
  

   series. 
  The 
  Palmer 
  hill 
  ore 
  body 
  is 
  particularly 
  interesting, 
  in 
  that 
  

   it 
  consists 
  of 
  a 
  magnetite 
  band 
  in 
  a 
  massive 
  augite-biotite 
  granite 
  

   that 
  carries 
  fluorspar. 
  This 
  mineral 
  forms 
  an 
  integral 
  part 
  of 
  the 
  

   ground 
  mass, 
  where 
  it 
  is 
  associated 
  with 
  quartz 
  and 
  feldspar 
  

   (microcline 
  and 
  orthoclase) 
  reaching 
  at 
  times 
  large 
  proportions. 
  

   Its 
  presence 
  can 
  hardly 
  be 
  explained 
  except 
  by 
  pneumatolytic 
  

   action 
  during 
  the 
  consolidation 
  of 
  the 
  rock 
  from 
  a 
  molten 
  state. 
  

   Fluorspar 
  is 
  a 
  quite 
  common 
  mineral 
  in 
  the 
  magnetites 
  elsewhere, 
  

   but 
  usually 
  in 
  small 
  quantities 
  and 
  limited, 
  so 
  far 
  as 
  observed, 
  to 
  

   pegmatite 
  or 
  vein 
  material. 
  

  

  Syenite 
  of 
  the 
  characteristic 
  Adirondack 
  type 
  is 
  represented 
  in 
  

   force 
  in 
  the 
  Mineville 
  group 
  of 
  mines. 
  It 
  has 
  been 
  shown 
  by 
  recent 
  

   drilling 
  to 
  underlie 
  the 
  ore 
  bodies 
  in 
  what 
  seems 
  to 
  be 
  a 
  continuous 
  

   mass. 
  The 
  rock 
  is 
  of 
  greenish 
  cast 
  and 
  is 
  normally 
  composed 
  of 
  

   microperthite, 
  green 
  augite, 
  hornblende 
  and 
  magnetite, 
  but 
  

   through 
  the 
  addition 
  of 
  quartz 
  and 
  shrinkage 
  of 
  the 
  ferromag- 
  

   nesian 
  constituents, 
  passes 
  into 
  a 
  lighter 
  reddish 
  rock 
  that 
  is 
  much 
  

   like 
  the 
  varieties 
  above 
  described. 
  This 
  rock 
  called 
  the 
  " 
  21 
  " 
  

   gneiss 
  in 
  the 
  earlier 
  report 
  of 
  Professor 
  Kemp, 
  forms 
  the 
  hanging 
  

   wall 
  of 
  the 
  Old 
  Bed 
  group. 
  Its 
  relations 
  to 
  the 
  underlying 
  syenite, 
  

   as 
  well 
  as 
  the 
  apparent 
  differentiation 
  of 
  the 
  latter 
  into 
  a 
  dioritic 
  

   phase, 
  are 
  brought 
  out 
  in 
  the 
  article 
  by 
  Professor 
  Kemp 
  included 
  

   herewith. 
  

  

  A 
  basic 
  variety 
  of 
  augite-syenite 
  constitutes 
  the 
  wall 
  rock 
  at 
  the 
  

   mine 
  near 
  Salisbury, 
  Herkimer 
  co., 
  being 
  a 
  part 
  of 
  the 
  intrusives 
  

   in 
  that 
  region 
  which 
  reach 
  southward' 
  from 
  the 
  Adirondacks 
  into 
  

   the 
  Mohawk 
  valley. 
  The 
  dark 
  minerals 
  (augite, 
  hornblende 
  and 
  

   magnetite) 
  constitute 
  about 
  75 
  per 
  cent 
  of 
  the 
  rock 
  in 
  immediate 
  

   contact 
  with 
  the 
  ore, 
  but 
  away 
  from 
  the 
  latter 
  there 
  is 
  a 
  gradual 
  

   change 
  into 
  the 
  normal 
  syenite. 
  

  

  While 
  the 
  rocks 
  from 
  the 
  different 
  mine 
  localities 
  have 
  not 
  been 
  

   chemically 
  analyzed, 
  the 
  following 
  tabulation 
  of 
  analyses 
  taken 
  

   from 
  a 
  recent 
  report 
  by 
  H. 
  P. 
  Cushing 
  1 
  may 
  be 
  useful 
  in 
  showing 
  

   the 
  general 
  range 
  of 
  the 
  igneous 
  series. 
  The 
  description 
  of 
  the 
  

  

  * 
  Geology 
  of 
  the 
  Long 
  Lake 
  Quadrangle. 
  N. 
  Y. 
  State 
  Mus. 
  Bui. 
  115. 
  1907. 
  

   p. 
  5«o- 
  

  

  