﻿It> 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  This 
  limestone 
  appears 
  to 
  correspond 
  with 
  the 
  lower 
  part 
  of 
  the 
  

   limestone 
  mass 
  in 
  figure 
  i. 
  

  

  There 
  is 
  no 
  positive 
  proof 
  that 
  the 
  quartizite 
  shown 
  in 
  figure 
  

   3 
  is 
  the 
  same 
  as 
  that 
  of 
  the 
  lower 
  part 
  of 
  figure 
  I, 
  but 
  the 
  two 
  rock 
  

   masses 
  are 
  of 
  much 
  the 
  same 
  character 
  and 
  both 
  are 
  of 
  great 
  thick- 
  

   ness. 
  This 
  quartzite 
  of 
  figure 
  3, 
  which 
  represents 
  a 
  section 
  across 
  

   the 
  valley 
  between 
  Chase 
  and 
  Bull 
  Rock 
  mountains, 
  is 
  nearly 
  pure 
  

   and 
  shows 
  a 
  thickness 
  of 
  about 
  3000 
  feet 
  with 
  banded 
  biotite-garnet 
  

   gneiss 
  dipping 
  under 
  it 
  on 
  the 
  west 
  side. 
  

  

  Figure 
  4 
  is 
  another 
  fine 
  section 
  of 
  the 
  quartzite 
  which 
  also 
  shows 
  

   the 
  underlying 
  rock 
  to 
  be 
  a 
  banded 
  biotite-garnet 
  gneiss 
  of 
  unknown 
  

   thickness. 
  

  

  The 
  limestone 
  of 
  the 
  Valentine 
  pond 
  valley 
  appears 
  to 
  dip 
  south- 
  

   ward 
  under 
  a 
  thick 
  belt 
  of 
  distinctly 
  light 
  and 
  dark 
  banded 
  garnet 
  

   gneisses, 
  but 
  just 
  where 
  these 
  rocks 
  belong 
  in 
  the 
  columnar 
  section 
  

   can 
  not 
  be 
  said. 
  

  

  The 
  quartzite 
  in 
  the 
  area 
  southwest 
  of 
  Thurman 
  is 
  often 
  very 
  

   tremolitic, 
  which 
  suggests 
  that 
  it 
  does 
  not 
  belong 
  with 
  the 
  other 
  

   quartzites 
  of 
  the 
  quadrangle. 
  

  

  QUARTZ 
  SYENITE 
  

  

  As 
  shown 
  on 
  the 
  geologic 
  map, 
  the 
  syenite 
  covers 
  about 
  two- 
  

   ninths 
  of 
  the 
  area 
  of 
  the 
  quadrangle 
  and 
  is 
  distributed 
  in 
  very 
  

   irregular 
  shaped 
  areas. 
  Boundary 
  lines 
  between 
  the 
  syenite 
  and 
  

   granite 
  can 
  not 
  be 
  sharply 
  drawn 
  because 
  of 
  the 
  gradation 
  of 
  the 
  

   one 
  rock 
  into 
  the 
  other. 
  Against 
  the 
  Grenville 
  the 
  boundary 
  is 
  

   generally 
  not 
  very 
  sharp 
  except 
  where 
  the 
  Grenville 
  has 
  been 
  

   faulted 
  against 
  the 
  syenite. 
  

  

  As 
  regards 
  granularity, 
  structure 
  and 
  mineral 
  composition 
  the 
  

   syenite 
  is 
  a 
  very 
  variable 
  rock. 
  The 
  granularity 
  ranges 
  from 
  fine 
  

   to 
  fairly 
  coarse 
  grain, 
  with 
  medium 
  grain 
  decidedly 
  prevalent 
  and 
  

   with 
  only 
  rarely 
  suggestions 
  of 
  a 
  porphyritic 
  texture. 
  Evidence 
  

   of 
  crushing 
  or 
  granulation 
  of 
  the 
  rock 
  is 
  common, 
  especially 
  in 
  

   the 
  cases 
  of 
  the 
  more 
  acid 
  (granitic) 
  syenites 
  where 
  the 
  feldspars 
  

   more 
  than 
  the 
  other 
  minerals 
  are 
  granulated. 
  In 
  structure 
  the 
  rock 
  

   ranges 
  from 
  only 
  faintly 
  gneissoid 
  to 
  very 
  clearly 
  gneissoid, 
  which 
  

   is 
  due 
  to 
  the 
  arrangement 
  of 
  the 
  dark 
  colored 
  minerals 
  with 
  axes 
  

   parallel 
  to 
  the 
  direction 
  of 
  foliation. 
  All 
  facies 
  of 
  the 
  syenite 
  are 
  

   quartzose 
  and 
  the 
  range 
  in 
  mineral 
  composition 
  is 
  from 
  pyroxene- 
  

   quartz-syenite 
  to 
  granitic 
  hornblende 
  syenite 
  as 
  shown 
  in 
  table 
  i. 
  1 
  

  

  1 
  In 
  this 
  and 
  the 
  succeeding 
  tables 
  only 
  close 
  approximation 
  to 
  the 
  volu- 
  

   metric 
  proportions 
  of 
  minerals 
  present 
  is 
  intended. 
  

  

  