﻿CLASSIFICATION, 
  ETC. 
  OF 
  HAMILTON 
  AND 
  CHEMUNG 
  SERIES 
  245 
  

  

  6 
  Ortlwnota 
  undulata 
  Con. 
  (c) 
  

  

  7 
  Modiomorpha 
  concent 
  rica 
  (Con.) 
  Hall 
  (rr) 
  

  

  8 
  Pholddella 
  radiata 
  (Con.) 
  Hall 
  ' 
  (rr) 
  

  

  9 
  Grammysia 
  bisirfcata 
  (Con.) 
  Hall 
  (rr) 
  

  

  10 
  ScMzodus 
  appressus 
  (Con.) 
  Hall 
  (rr) 
  

  

  11 
  Pterinea 
  flabella 
  (Con.) 
  Hall 
  (rr) 
  

  

  12 
  Orthoceras 
  crotalum 
  Hall 
  (rr) 
  

   .13 
  Microdon 
  (Gypricardella) 
  tenuistriatus 
  Hall 
  (rr) 
  

  

  On 
  the 
  highway 
  just 
  west 
  of 
  the 
  Bradt 
  hill 
  four 
  corners 
  are 
  

   green 
  shales 
  of 
  the 
  Sherburne 
  formation. 
  

  

  The 
  Turner, 
  schoolhouse, 
  district 
  no. 
  20, 
  is 
  at 
  the 
  first 
  four 
  cor- 
  

   ners, 
  one 
  mile 
  south 
  of 
  the 
  Bradt 
  hill 
  corners 
  and 
  some 
  60 
  feet 
  

   lower, 
  and 
  on 
  the 
  highway 
  not 
  far 
  east 
  of 
  the 
  schoolhouse 
  are 
  red 
  

   argillaceous 
  shales. 
  The 
  southerly 
  dip, 
  however, 
  has 
  carried 
  the 
  

   rocks 
  down 
  so 
  that 
  these 
  shales 
  are 
  stratigraphically 
  higher 
  than 
  

   those 
  on 
  top 
  of 
  Bradt 
  hill. 
  These 
  red 
  shales 
  form 
  a 
  conspicuous 
  

   zone 
  and 
  were 
  mapped 
  as 
  at 
  the 
  base 
  of 
  the 
  Oneonta 
  formation, 
  

   which 
  covers 
  the 
  high 
  land 
  beyond 
  the 
  first 
  four 
  corners 
  east 
  of 
  the 
  

   Turner 
  schoolhouse. 
  This 
  region 
  forms 
  the 
  high 
  divide 
  between 
  

   the 
  head 
  waters 
  of 
  Stony 
  brook, 
  Tenmile 
  creek 
  and 
  the 
  Switzkill, 
  

   four 
  miles 
  northwest 
  of 
  Kensselaerville 
  and 
  some 
  600 
  feet 
  higher. 
  

   On 
  the 
  divide 
  to 
  the 
  west 
  of 
  the 
  four 
  corners 
  are 
  bluish 
  gray 
  thin 
  

   sandstones 
  differing 
  inappreciably 
  from 
  Hamilton 
  sandstones, 
  

   while 
  some 
  30 
  feet 
  lower 
  at 
  the 
  corners 
  are 
  red 
  shales. 
  The 
  coarser 
  

   rocks 
  form 
  terraces 
  that 
  slope 
  rapidly 
  to 
  the 
  southwest. 
  

  

  On 
  comparison 
  with 
  the 
  Geologic 
  map 
  of 
  Neio 
  York 
  it 
  will 
  be 
  seen 
  

   that 
  the 
  boundary 
  of 
  the 
  Oneonta 
  formation 
  for 
  this 
  region 
  agrees 
  

   closely 
  with 
  that 
  outlined 
  on 
  the 
  accompanying 
  map 
  except 
  that 
  

   od 
  the 
  former 
  it 
  is 
  carried 
  somewhat 
  farther 
  northwest, 
  indicating 
  

   that 
  the 
  red 
  shales 
  mentioned 
  above 
  were 
  considered 
  as 
  forming 
  its 
  

   base. 
  In 
  fact, 
  Darton 
  said, 
  "In 
  mapping 
  the 
  Oneonta 
  formation, 
  

   in 
  Albany 
  county 
  I 
  have 
  assumed 
  that 
  its 
  base 
  was 
  at 
  the 
  bottom 
  

   of 
  the 
  lowest 
  red 
  shale 
  member 
  because 
  this 
  was 
  the 
  only 
  dis- 
  

   tinguishing 
  feature 
  that 
  I 
  could 
  use 
  as 
  a 
  guide. 
  Probably 
  this 
  

  

  