﻿CLASSIFICATION, 
  ETC. 
  OP 
  HAMILTON 
  AND 
  CHEMUNG 
  SERIES 
  273 
  

  

  was 
  recognized 
  by 
  Dr 
  Hall 
  as 
  Spirifer 
  disjunctus, 
  a 
  Chemung 
  

   form."* 
  

  

  In 
  our 
  search 
  we 
  were 
  not 
  successful 
  in 
  finding 
  fossils 
  in 
  this 
  

   zone 
  except 
  Lepidodendron 
  sp. 
  and 
  fragments 
  of 
  plant 
  stems. 
  It 
  

   is 
  very 
  evident 
  however 
  that 
  there 
  are 
  no 
  250 
  feet 
  of 
  coarse, 
  gray 
  

   sandstones, 
  but 
  in 
  the 
  upper 
  half 
  of 
  the 
  zone 
  are 
  heavy 
  layers 
  of 
  

   grayish 
  to 
  greenish 
  gray 
  sandstones 
  alternating 
  with 
  red 
  shales 
  

   and 
  sandstones. 
  The 
  lower 
  half 
  of 
  the 
  zone 
  is 
  composed 
  largely 
  

   of 
  red 
  rocks, 
  but 
  in 
  the 
  upper 
  half 
  there 
  are 
  two 
  heavy 
  ledges 
  of 
  

   the 
  greenish 
  gray 
  sandstones 
  separated 
  by 
  red 
  and 
  green 
  shales 
  

   with 
  a 
  thickness 
  of 
  from 
  70 
  to 
  80 
  feet. 
  On 
  the 
  hill 
  to 
  the 
  south 
  

   of 
  the 
  pass 
  the 
  rocks 
  are 
  largely 
  red 
  shales 
  and 
  sandstones 
  with 
  

   some 
  layers 
  of 
  greenish 
  sandstone. 
  This 
  hill 
  is 
  mapped 
  as 
  in 
  the 
  

   lower 
  part 
  of 
  the 
  Catskill 
  formation 
  on 
  the 
  Geologic 
  map 
  of 
  New 
  

   YorJc 
  and 
  it 
  has 
  an 
  approximate 
  altitude 
  of 
  2490 
  feet 
  A. 
  T. 
  

  

  LVII 
  C. 
  To 
  the 
  southeast 
  of 
  the 
  point 
  just 
  described 
  on 
  the 
  

   southern 
  side 
  of 
  Sutton 
  gap 
  is 
  Mt 
  Pisgah, 
  at 
  the 
  corner 
  of 
  Cones- 
  

   ville 
  and 
  Durham 
  townships, 
  which 
  is 
  given 
  as 
  2885 
  feet 
  A. 
  T. 
  on 
  

   the 
  " 
  Durham 
  sheet" 
  of 
  the 
  United 
  States 
  geological 
  survey. 
  

   For 
  my 
  barometric 
  section 
  I 
  obtained 
  an 
  altitude 
  of 
  2940 
  feet 
  A. 
  

   T., 
  but 
  the 
  readings 
  were 
  probably 
  affected 
  by 
  rain. 
  Guyot 
  gave 
  

   its 
  altitude, 
  determined 
  by 
  the 
  barometer, 
  as 
  2905 
  feet. 
  The 
  ac- 
  

   companying 
  section 
  of 
  the 
  southern 
  side 
  of 
  Mt 
  Pisgah 
  gives 
  the 
  

   relative 
  position 
  and 
  thickness 
  of 
  the 
  prominent 
  ledges 
  shown 
  on 
  

   its 
  flank. 
  Not 
  much 
  above 
  the 
  highway 
  on 
  the 
  south 
  side 
  of 
  the 
  

   mountain 
  are 
  two 
  conspicuous 
  ledges 
  of 
  massive, 
  greenish 
  gray 
  

   sandstone, 
  the 
  lower 
  one 
  (C 
  3 
  ) 
  30 
  feet 
  thick 
  with 
  red 
  sandstone 
  on 
  

   top, 
  and 
  the 
  upper 
  one 
  (C 
  5 
  ) 
  15 
  feet 
  thick 
  above 
  which 
  is 
  red 
  shale. 
  

   The 
  dip 
  of 
  this 
  sandstone 
  is 
  between 
  3£° 
  and 
  4° 
  S, 
  30° 
  W. 
  On 
  

   the 
  Geologic 
  map 
  of 
  New 
  York 
  the 
  area 
  of 
  these 
  sandstones 
  is 
  

   colored 
  as 
  in 
  the 
  Chemung 
  formation 
  and 
  it 
  is 
  probable 
  that 
  they 
  

   are 
  stratigraphically 
  in 
  the 
  upper 
  part 
  of 
  the 
  zone 
  called 
  Che- 
  

   mung 
  on 
  the 
  Catskill 
  turnpike 
  to 
  the 
  north, 
  though 
  the 
  heavy 
  

   dip 
  to 
  the 
  south 
  would 
  carry 
  those 
  sandstones 
  rapidly 
  below 
  the 
  

   altitude 
  which 
  they 
  have 
  on 
  that 
  highway. 
  For 
  the 
  succeeding 
  

  

  a 
  Araer. 
  jour, 
  science, 
  3d 
  ser. 
  1893. 
  45:207. 
  

  

  