﻿GEOLOGY 
  OF 
  SARATOGA 
  SPRINGS 
  AND 
  VICINITY 
  87 
  

  

  frequently 
  minute, 
  pale, 
  greenish, 
  slaty 
  particles. 
  Under 
  the 
  miscroscope, 
  it 
  

   consists 
  of 
  angular 
  grains 
  of 
  quartz, 
  orthoclase, 
  plagioclase, 
  and 
  scales 
  of 
  

   muscovite, 
  probably 
  clastic. 
  The 
  cement 
  contains 
  not 
  a 
  little 
  carbonaceous 
  

   matter, 
  secondary 
  calcite, 
  and 
  pyrite. 
  In 
  the 
  more 
  easterly 
  Ordovician 
  area 
  

   the 
  cement 
  is 
  quite 
  sericitic 
  and 
  the 
  feldspar 
  is 
  partially 
  sericitized, 
  but 
  

   in 
  other 
  places 
  and 
  along 
  the 
  Hudson, 
  in 
  Rensselaer 
  county, 
  the 
  amount 
  of 
  

   sericite 
  in 
  the 
  cement 
  is 
  small. 
  The 
  marked 
  features 
  are 
  the 
  heterogeneity 
  

   of 
  the 
  fragments, 
  their 
  irregular 
  size, 
  angular 
  outline, 
  and 
  usually 
  the 
  absence 
  

   of 
  any 
  arrangement 
  in 
  them. 
  Chlorite 
  is 
  rarely 
  present. 
  

  

  A 
  further 
  peculiarity 
  of 
  the 
  Hudson 
  grits 
  is 
  that 
  they 
  contain 
  particles 
  of 
  

   various 
  fragmental 
  rocks, 
  showing 
  that 
  they 
  were 
  derived 
  from 
  the 
  erosion 
  

   not 
  only 
  of 
  older 
  granites 
  and 
  gneisses, 
  but 
  of 
  sedimentary 
  rocks 
  of 
  

   Ordovician 
  or 
  pre-Ordovician 
  age. 
  The 
  particles 
  of 
  clastic 
  rocks 
  were 
  found 
  

   to 
  consist 
  of 
  shale, 
  micaceous 
  quartzite, 
  calcareous 
  quartzite, 
  limestone 
  or 
  

   dolomite, 
  slate 
  and 
  flint. 
  The 
  most 
  abundant 
  were 
  found 
  to 
  be 
  quartzite, 
  

   slate 
  and 
  shale. 
  

  

  Dale 
  recorded 
  the 
  occurrence 
  of 
  graptolites 
  of 
  the 
  Normanskill 
  

   horizon 
  from 
  the 
  shales 
  interbedded 
  in 
  the 
  Hudson 
  grits. 
  

  

  Like 
  the 
  white 
  beds, 
  the 
  grit 
  beds 
  of 
  the 
  Normanskill 
  shale 
  

   come 
  to 
  the 
  surface 
  on 
  the 
  Schuylerville 
  quadrangle 
  in 
  two 
  well- 
  

   circumscribed 
  areas. 
  The 
  grit 
  ledges 
  on 
  this 
  map 
  are 
  denoted 
  by 
  

   the 
  brown 
  symbol 
  and 
  are 
  crowded 
  in 
  the 
  region 
  west 
  and 
  north 
  

   of 
  Quaker 
  Springs 
  and 
  about 
  Willard 
  mountain. 
  The 
  former 
  

   region 
  is 
  one 
  of 
  extremely 
  rough 
  topography, 
  owing 
  to 
  the 
  many 
  

   broken 
  edges 
  of 
  the 
  grit 
  beds 
  in 
  the 
  closed 
  synclines 
  and 
  anticlines. 
  

   It 
  is 
  for 
  this 
  reason 
  locally 
  known 
  as 
  " 
  The 
  rocky 
  tucks 
  " 
  and 
  was 
  

   formerly 
  the 
  site 
  of 
  considerable 
  quarrying 
  for 
  sills 
  and 
  building 
  

   stone. 
  The 
  ledges 
  are 
  especially 
  well 
  seen 
  in 
  the 
  neighborhood 
  

   of 
  Quaker 
  Springs. 
  The 
  interbedded 
  shale 
  is 
  but 
  rarely 
  seen, 
  

   since 
  it 
  usually 
  has 
  weathered 
  back 
  too 
  far 
  and 
  is 
  covered 
  by 
  drift. 
  

   In 
  one 
  place, 
  at 
  least, 
  we 
  found 
  graptolites 
  of 
  Normanskill 
  type 
  in 
  

   the 
  interbedded 
  shale. 
  The 
  grit 
  itself 
  is 
  barren 
  of 
  fossils, 
  a 
  few 
  

   joints 
  of 
  crinoid 
  stems 
  being 
  the 
  only 
  traces 
  of 
  fossils 
  observed. 
  

  

  The 
  belt 
  of 
  grit 
  ledges 
  ends 
  rather 
  abruptly 
  about 
  a 
  mile 
  south 
  

   of 
  Gates, 
  or 
  2 
  miles 
  south 
  of 
  the 
  north 
  bend 
  of 
  Fish 
  creek, 
  not 
  to 
  

   reappear 
  farther 
  north 
  on 
  the 
  quadrangle. 
  

  

  The 
  second 
  region 
  of 
  grit 
  outcrops 
  is 
  the 
  Willard 
  mountain 
  

   ridge. 
  As 
  we 
  noted 
  before, 
  the 
  top 
  of 
  this 
  very 
  prominent 
  ridge 
  

   is 
  formed 
  by 
  the 
  white-weathering 
  cherty 
  beds; 
  the 
  flanks 
  con- 
  

   sist, 
  however, 
  of 
  the 
  Normanskill 
  grit. 
  The 
  grit 
  ledges 
  appear 
  

   very 
  prominently 
  along 
  the 
  lower 
  road 
  west 
  of 
  the 
  mountain. 
  

   They 
  form 
  considerable 
  cliffs 
  on 
  the 
  northwest 
  side 
  of 
  the 
  Willard 
  

   ridge 
  and 
  are 
  observable 
  in 
  outcrops 
  and 
  cliffs 
  along 
  the 
  road 
  

  

  