﻿12 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  A 
  hand 
  specimen, 
  from 
  the 
  prospect 
  hole 
  2 
  l 
  / 
  2 
  miles 
  south 
  of 
  

   Pottersville, 
  is 
  a 
  very 
  coarse-grained 
  mass 
  of 
  calcite, 
  brown 
  horn- 
  

   blende, 
  and 
  graphite 
  through 
  which 
  are 
  scattered 
  small 
  flakes 
  or 
  

   crystals 
  of 
  phlogopite, 
  pyrite, 
  and 
  pyroxene 
  (mostly 
  serpentin- 
  

   ized). 
  The 
  hornblende 
  and 
  calcite 
  crystals 
  are 
  as 
  much 
  as 
  an 
  inch 
  

   across. 
  

  

  Qaartzite. 
  In 
  the 
  quartzite 
  areas 
  shown 
  on 
  the 
  map 
  south 
  of 
  

   Sodom, 
  south 
  of 
  Pottersville, 
  and 
  east 
  of 
  Chase 
  mountain, 
  the 
  rock 
  

   consists 
  almost 
  wholly 
  of 
  distinctly 
  bedded, 
  pure 
  quartzite 
  (with 
  

   layers 
  up 
  to 
  iy 
  2 
  feet 
  thick) 
  interstratified 
  with 
  thin 
  layers 
  of 
  

   biotite-quartz 
  gneiss. 
  

  

  The 
  quartzite 
  of 
  the 
  area 
  southwest 
  of 
  Thurman 
  contains 
  many 
  

   closely 
  involved 
  tremolite 
  and 
  limestone 
  beds. 
  

  

  Thin 
  layers 
  of 
  quartzite 
  are 
  occasionally 
  present 
  in 
  the 
  other 
  

   Grenville 
  areas 
  but 
  these 
  are 
  usually 
  rather 
  impure 
  containing 
  

   more 
  or 
  less 
  feldspar, 
  biotite, 
  muscovite 
  or 
  graphite. 
  

  

  Hornblende-garnet-feldspar 
  gneisses. 
  Of 
  the 
  two 
  principal 
  

   facies 
  of 
  these 
  gneisses, 
  one 
  is 
  a 
  gray, 
  medium 
  to 
  fairly 
  coarse- 
  

   grained 
  hornblende-feldspar 
  gneiss 
  in 
  which 
  are 
  embedded 
  occa- 
  

   sional 
  large 
  brownish 
  red 
  garnets 
  of 
  the 
  almandite 
  type. 
  The 
  felds- 
  

   pars 
  comprise 
  both 
  orthoclase 
  and 
  plagioclase 
  and 
  the 
  hornblende 
  

   is 
  very 
  dark 
  green 
  to 
  nearly 
  black. 
  Biotite, 
  magnetite, 
  and 
  pyrite 
  

   generally 
  occur 
  in 
  small 
  amounts. 
  The 
  garnets 
  never 
  show 
  crystal 
  

   form 
  but 
  are 
  always 
  more 
  or 
  less 
  rounded 
  and 
  highly 
  fractured. 
  

   These 
  garnets 
  commonly 
  range 
  in 
  size 
  from 
  one 
  to 
  five 
  inches 
  and 
  

   are 
  often 
  surrounded 
  by 
  rims 
  or 
  envelops 
  of 
  pure 
  hornblende 
  

   crystals. 
  Fine 
  specimens 
  of 
  such 
  garnets, 
  surrounded 
  by 
  rims 
  of 
  

   hornblende 
  and 
  embedded 
  in 
  the 
  gray 
  matrix, 
  may 
  be 
  obtained 
  

   at 
  the 
  old 
  garnet 
  mines 
  near 
  the 
  top 
  of 
  Oven 
  mountain 
  and 
  south 
  

   of 
  Holcombville. 
  

  

  Another 
  facies 
  is 
  fine 
  to 
  medium-grained, 
  darker 
  gray 
  (with 
  

   reddish 
  tinge), 
  less 
  feldspathic, 
  and 
  more 
  garnetiferous 
  but 
  with 
  

   the 
  reddish 
  brown 
  garnets 
  all 
  very 
  small 
  and 
  rather 
  evenly 
  scat- 
  

   tered 
  through 
  the 
  rock. 
  Small 
  amounts 
  of 
  magnetite, 
  quartz, 
  and 
  

   pyrite 
  are 
  also 
  usually 
  present. 
  

  

  These 
  hornblende-garnet-feldspar 
  gneisses 
  are 
  almost 
  invariably 
  

   closely 
  associated 
  with 
  the 
  limestone 
  beds, 
  the 
  two 
  rocks 
  often 
  

   appearing 
  in 
  a 
  single 
  outcrop. 
  Numerous 
  fine 
  exposures 
  may 
  be 
  

   seen 
  along 
  the 
  south 
  and 
  west 
  sides 
  of 
  Crane 
  mountain, 
  i 
  mile 
  

   west 
  of 
  Pine 
  mountain, 
  just 
  northwest 
  of 
  No. 
  9 
  mountain, 
  and 
  

   1 
  mile 
  east 
  of 
  Cherry 
  ridge. 
  

  

  