﻿GEOLOGY 
  OF 
  SARATOGA 
  SPRINGS 
  AND 
  VICINITY 
  JI 
  

  

  number 
  of 
  plagioclase 
  grains, 
  rarely 
  one 
  of 
  microcline, 
  in 
  a 
  cement 
  of 
  sericite 
  

   with 
  some 
  calcite 
  and 
  small 
  areas 
  of 
  secondary 
  quartz. 
  There 
  are 
  large 
  

   scales 
  of 
  muscovite 
  and 
  of 
  a 
  chloritic 
  mineral, 
  scarcely 
  dichroic, 
  and 
  under 
  

   polarized 
  light 
  a 
  bluish 
  green 
  or 
  prussian 
  blue, 
  with 
  little 
  or 
  no 
  change 
  in 
  

   rotation. 
  More 
  conspicuous 
  and 
  typical 
  of 
  the 
  rock 
  are 
  scales 
  from 
  0.043 
  to 
  

   0.130 
  by 
  0.020 
  millimeter, 
  frequently 
  bent, 
  pale 
  green, 
  markedly 
  dichroic, 
  and 
  

   under 
  polarized 
  light 
  olive 
  or 
  slightly 
  bluish 
  green. 
  These 
  scales 
  contain 
  

   bands 
  of 
  a 
  colorless 
  mineral 
  parallel 
  to 
  their 
  cleavage, 
  which 
  measure 
  0.0043 
  

   in 
  width 
  and 
  polarize 
  in 
  brilliant 
  orange, 
  emerald 
  or 
  blue. 
  Extinction 
  in 
  

   both 
  about 
  (if 
  not 
  quite) 
  parallel 
  to 
  cleavage 
  and 
  bands. 
  Finally, 
  there 
  are 
  

   grains 
  or 
  crystals 
  of 
  a 
  muddy 
  yellow 
  under 
  incident 
  light, 
  probably 
  limonite 
  

   and 
  that 
  after 
  hematite. 
  The 
  scales 
  of 
  hematite, 
  sometimes 
  graphite, 
  can 
  be 
  

   made 
  out 
  with 
  a 
  magnifying 
  glass. 
  

  

  This 
  characteristic 
  rock 
  can 
  usually 
  be 
  identified 
  at 
  a 
  distance 
  by 
  the 
  

   peculiar 
  pale 
  brick-red 
  color 
  of 
  its 
  weathered 
  surface, 
  and, 
  on 
  closer 
  in- 
  

   spection, 
  by 
  the 
  minute 
  spangles 
  and 
  the 
  olive 
  color 
  of 
  the 
  fresh 
  surface. 
  

  

  The 
  olive 
  grit 
  has 
  not 
  furnished 
  any 
  fossils, 
  but 
  it 
  was 
  found 
  

   full 
  of 
  carbonaceous 
  blotches, 
  suggesting 
  seaweeds, 
  and 
  large 
  worm 
  

   trails. 
  It 
  is 
  apparently 
  a 
  shallow 
  water 
  deposit. 
  

  

  The 
  belts 
  of 
  heavier 
  grit 
  beds 
  alternate 
  with 
  belts* 
  of 
  more 
  slaty, 
  

   often 
  brownish 
  weathering 
  beds, 
  apparently 
  resulting 
  from 
  the 
  grit 
  

   through 
  a 
  stronger 
  development 
  of 
  the 
  cleavage. 
  These 
  belts 
  were 
  

   found 
  to 
  be 
  worn 
  down 
  more, 
  forming 
  the 
  depressions 
  between 
  the 
  

   ridges 
  of 
  harder 
  grit. 
  

  

  The 
  hills 
  composed 
  of 
  this 
  rock 
  are 
  frequently 
  discerned 
  from 
  a 
  

   distance 
  through 
  the 
  reddish 
  color 
  of 
  the 
  soil 
  they 
  furnish. 
  The 
  

   Georgian 
  limestones 
  were 
  also 
  found 
  to 
  weather 
  into 
  soils 
  of 
  reddish 
  

   tints 
  so 
  that 
  as 
  a 
  whole 
  the 
  Georgian 
  areas 
  of 
  this 
  region 
  can, 
  to 
  a 
  

   large 
  degree, 
  be 
  distinguished 
  from 
  the 
  Ordovicic 
  shale 
  areas 
  by 
  

   the 
  soils, 
  wherever 
  the 
  drift 
  is 
  thin 
  or 
  its 
  lower 
  portion 
  exposed, 
  for, 
  

   as 
  a 
  rule, 
  this 
  also 
  contains 
  so 
  much 
  material 
  derived 
  from 
  the 
  under- 
  

   lying 
  rocks 
  that 
  it 
  partakes 
  of 
  the 
  reddish 
  color. 
  The 
  olive 
  grit 
  forms 
  

   a 
  belt 
  beginning 
  at 
  the 
  projecting 
  southeast 
  corner 
  of 
  the 
  Georgian 
  

   area 
  south 
  of 
  Louse 
  hill, 
  continuing 
  over 
  Louse 
  hill 
  and 
  exposed 
  

   on 
  its 
  north 
  slope, 
  on 
  the 
  banks 
  of 
  the 
  Batten 
  kill, 
  continuing 
  north 
  

   of 
  Greenwich 
  to 
  the 
  central 
  and 
  eastern 
  peaks 
  of 
  the 
  Bald 
  mountain 
  

   ridge. 
  *— 
  

  

  South 
  and 
  east 
  of 
  Louse 
  hill 
  the 
  olive 
  grit 
  or 
  the 
  Bomoseen 
  is 
  

   flanked 
  by 
  massive 
  ledges 
  of 
  gray 
  quartzite 
  speckled 
  with 
  brown 
  

   spots 
  of 
  limonite. 
  We 
  consider 
  this 
  bed 
  as 
  corresponding 
  to 
  the 
  

   massive 
  beds 
  of 
  quartzite 
  found 
  farther 
  east 
  by 
  Dale 
  in 
  association 
  

   with 
  the 
  Bomoseen 
  grit. 
  On 
  the 
  centre 
  peak 
  of 
  Bald 
  mountain, 
  the 
  

   Bomoseen 
  grit 
  is 
  flanked 
  on 
  both 
  sides 
  by 
  quartzite 
  beds 
  which 
  are 
  

  

  