﻿GEOLOGY 
  OF 
  SARATOGA 
  SPRINGS 
  AND 
  VICINITY 
  93 
  

  

  D. 
  contortus 
  Ruedemann 
  

  

  Climacograptus 
  bicornis 
  Hall 
  

  

  C. 
  parvus 
  Hall 
  

  

  C. 
  putillus 
  var. 
  eximius 
  Ruedemann 
  

  

  Glossograptus 
  ciliatus 
  Emmons 
  

  

  Lasiograptus 
  bimucronatus 
  (Hall) 
  

  

  Leptobolus 
  sp. 
  

  

  Correlation. 
  The 
  writer, 
  finding 
  the 
  Normanskill 
  shale 
  below 
  

   beds 
  with 
  Diplograptus 
  amplexicaulis, 
  had 
  inferred 
  

   (1901) 
  that 
  it 
  was 
  at 
  least 
  as 
  old 
  or 
  older 
  than 
  middle 
  Trenton 
  and 
  

   correlated 
  it 
  with 
  the 
  middle 
  and 
  lower 
  Trenton. 
  It 
  appears 
  now 
  

   from 
  evidence 
  obtained 
  by 
  Ulrich 
  (op. 
  cit. 
  page 
  512) 
  in 
  the 
  Athens 
  

   trough, 
  that 
  the 
  formation 
  is 
  still 
  older 
  and 
  corresponds 
  in 
  age 
  to 
  

   the 
  upper 
  Chazy. 
  But 
  the 
  Rysedorph 
  Hill 
  conglomerate 
  of 
  Black 
  

   River 
  age 
  is 
  intercalated 
  in 
  the 
  Normanskill 
  shale 
  in 
  a 
  number 
  of 
  

   localities, 
  some 
  of 
  which 
  have 
  been 
  cited 
  above 
  (page 
  82) 
  and 
  to 
  

   which 
  may 
  be 
  added 
  the 
  fossiliferous 
  exposure 
  of 
  the 
  conglomerate 
  

   in 
  the 
  big 
  cut 
  of 
  the 
  Boston 
  & 
  Albany 
  Railroad 
  south 
  of 
  Rensselaer. 
  

  

  These 
  militating 
  observations 
  of 
  the 
  Chazy 
  age 
  of 
  the 
  Normans- 
  

   kill 
  shale 
  and 
  of 
  the 
  intercalation 
  of 
  the 
  Rysedorph 
  Hill 
  con- 
  

   glomerate 
  of 
  Black 
  River 
  age, 
  appear 
  to 
  find 
  their 
  solution 
  from 
  

   observations 
  made 
  lately 
  by 
  the 
  writer, 
  leading 
  to 
  the 
  inference 
  

   that 
  the 
  Normanskill 
  shale 
  comprises 
  two 
  divisions 
  or 
  formations, 
  

   the 
  lower 
  of 
  which 
  is 
  of 
  Chazy 
  age 
  and 
  the 
  upper 
  of 
  Black 
  River 
  

   age 
  and 
  possibly 
  somewhat 
  younger. 
  This 
  upper 
  formation 
  con- 
  

   tains 
  the 
  Rysedorph 
  Hill 
  conglomerate. 
  The 
  inference 
  of 
  the 
  sub- 
  

   division 
  of 
  the 
  Normanskill 
  shale 
  is 
  based 
  partly 
  upon 
  an 
  unmis- 
  

   takable 
  distinction 
  in 
  the 
  graptolite 
  faunules, 
  indicating 
  an 
  older 
  

   and 
  a 
  later 
  horizon 
  — 
  to 
  be 
  worked 
  out 
  more 
  fully 
  when 
  favorable 
  

   sections 
  present 
  themselves 
  — 
  and 
  partly 
  upon 
  the 
  observation 
  of 
  

   traces 
  of 
  other 
  fossils 
  than 
  graptolites 
  and 
  younger 
  than 
  Chazyan 
  

   in 
  age 
  in 
  the 
  upper 
  Normanskill 
  shale. 
  

  

  SNAKE 
  HILL 
  BEDS 
  

  

  The 
  Snake 
  Hill 
  formation 
  occupies 
  the 
  southeast 
  corner 
  of 
  the 
  

   Saratoga 
  quadrangle, 
  from 
  Ballston 
  Spa 
  and 
  the 
  Kayaderosseras 
  

   creek 
  to 
  Saratoga 
  lake. 
  It 
  crosses 
  the 
  Schuylerville 
  quadrangle 
  

   diagonally 
  as 
  a 
  belt 
  4 
  to 
  5 
  miles 
  wide, 
  and 
  a 
  second 
  eastern 
  belt 
  

   follows 
  the 
  Hudson 
  river 
  and 
  unites 
  with 
  the 
  western 
  belt 
  north 
  

   of 
  the 
  Batten 
  kill. 
  These 
  belts 
  are 
  segments 
  of 
  a 
  greater 
  belt 
  that 
  

   extends 
  from 
  Pennsylvania 
  through 
  southern 
  New 
  York 
  along 
  the 
  

  

  