﻿GEOLOGY 
  OF 
  SARATOGA 
  SPRINGS 
  AND 
  VICINITY 
  5 
  1 
  

  

  As 
  a 
  rule, 
  one 
  meets 
  only 
  Corynoides 
  calicularis 
  and 
  

   Lasiograptus 
  eucharis, 
  the 
  two 
  most 
  common 
  fossils, 
  as 
  

   at 
  the 
  Glowegee 
  and 
  the 
  upper 
  branches 
  of 
  the 
  Snook 
  kill. 
  At 
  

   the 
  Gansevoort 
  fall, 
  however, 
  also 
  Glossograptus 
  quadri- 
  

   mucronatus 
  mut. 
  cornutus, 
  a 
  characteristic 
  form 
  of 
  an 
  

   upper 
  horizon 
  of 
  the 
  Canajoharie 
  shale 
  was 
  obtained 
  in 
  typical 
  

   specimens. 
  

  

  Correlation. 
  We 
  have 
  shown 
  in 
  another 
  paper, 
  1 
  that 
  the 
  Cana- 
  

   joharie 
  is 
  of 
  lower 
  Trenton 
  age 
  and 
  essentially 
  contemporaneous 
  

   with 
  the 
  Snake 
  Hill 
  shale. 
  The 
  two 
  have, 
  therefore, 
  some 
  import- 
  

   ant 
  horizon 
  markers, 
  especially 
  graptolites, 
  in 
  common. 
  While, 
  

   however, 
  the 
  Snake 
  Hill 
  shale 
  rests 
  on 
  either 
  upper 
  Normanskill 
  

   shale 
  or 
  Rysedorph 
  Hill 
  conglomerate 
  and 
  belongs 
  to 
  a 
  vertical 
  

   series 
  that 
  begins 
  with 
  the 
  Georgian 
  beds 
  at 
  the 
  bottom, 
  the 
  Cana- 
  

   joharie 
  shale 
  can 
  be 
  seen 
  to 
  rest 
  on 
  the 
  basal 
  Trenton 
  limestone 
  

   at 
  Glens 
  Falls, 
  the 
  latter 
  being 
  underlain 
  in 
  turn 
  by 
  the 
  Amsterdam 
  

   limestone. 
  It 
  is 
  therefore 
  to 
  be 
  inferred 
  that 
  although 
  the 
  Cana- 
  

   joharie 
  and 
  Snake 
  Hill 
  shales 
  may 
  be 
  approximately 
  synchronous, 
  

   they 
  were 
  formed 
  in 
  different 
  basins 
  and 
  have 
  come 
  in 
  contact 
  

   through 
  later 
  diastrophic 
  movements 
  (see 
  diagram 
  and 
  page 
  100.) 
  

  

  The 
  Canajoharie 
  shale 
  is 
  equivalent 
  to 
  the 
  lower 
  part 
  of 
  the 
  Mar- 
  

   tinsburg 
  shale 
  in 
  Pennsylvania 
  and 
  New 
  Jersey, 
  with 
  which 
  it 
  has 
  

   the 
  characteristic 
  fossils 
  in 
  common 
  and 
  is 
  probably 
  continuous 
  

   with 
  it 
  through 
  southern 
  New 
  York. 
  The 
  Martinsburg 
  shale, 
  how- 
  

   ever, 
  comprises 
  also 
  beds 
  of 
  Utica 
  and 
  Eden 
  age. 
  

  

  THE 
  SCHENECTADY 
  FORMATION 
  

  

  In 
  the 
  southwestern 
  corner 
  of 
  the 
  Saratoga 
  sheet, 
  from 
  Birchton 
  

   westward, 
  the 
  grits 
  of 
  the 
  Schenectady 
  formation 
  are 
  exposed 
  in 
  a 
  

   number 
  of 
  places, 
  showing 
  that 
  this 
  formation 
  just 
  reaches 
  the 
  sheet 
  

   from 
  the 
  southwest. 
  

  

  The 
  Schenectady 
  formation 
  consists 
  in 
  the 
  lower 
  Mohawk 
  valley 
  

   of 
  2000 
  feet 
  of 
  grits 
  and 
  sandstones 
  with 
  interbedded 
  black 
  and 
  

   gray 
  argillaceous 
  shales, 
  the 
  two 
  forming 
  a 
  monotonous, 
  uniformly 
  

   alternating 
  series 
  throughout 
  this 
  great 
  thickness. 
  The 
  sandstone 
  

   beds 
  are 
  quarried 
  about 
  Schenectady 
  and 
  Aqueduct, 
  and 
  in 
  the 
  

   latter 
  place, 
  where 
  the 
  Mohawk 
  river 
  in 
  its 
  new 
  postglacial 
  course 
  

   breaks 
  through 
  a 
  ridge 
  of 
  these 
  harder 
  beds, 
  an 
  excellent 
  section 
  of 
  

   a 
  portion 
  of 
  the 
  formation 
  is 
  furnished. 
  These 
  gray, 
  impure 
  sand- 
  

   stones 
  and 
  gray 
  to 
  black 
  argillaceous 
  shales 
  have, 
  until 
  recently, 
  

  

  X 
  N. 
  Y. 
  State 
  Mus. 
  Bui. 
  162, 
  p. 
  29. 
  

  

  