﻿STRATIGRAPHIC 
  GEOLOGY 
  OF 
  THE 
  EASTERN 
  HELDERBERGS 
  347 
  

  

  Feet 
  

  

  formation 
  are 
  well 
  exposed 
  as 
  well 
  as 
  its 
  gradual 
  

   transition 
  to 
  the 
  arenaceous 
  shales 
  of 
  the 
  Hamil- 
  

   ton. 
  The 
  lower 
  100 
  feet 
  or 
  more 
  of 
  this 
  formation 
  

   are 
  covered, 
  after 
  that 
  there 
  are 
  about 
  80 
  feet 
  of 
  

   black, 
  argillaceous 
  shales, 
  then 
  about 
  30 
  feet 
  of 
  

   shales 
  of 
  this 
  character 
  interspersed 
  frequently 
  

   with 
  layers 
  of 
  slightly 
  calcareous, 
  dark 
  sandstone 
  

   above 
  which 
  are 
  85 
  feet 
  of 
  dark, 
  argillaceous 
  shales. 
  

   It 
  is 
  rather 
  difficult 
  to 
  distinguish 
  the 
  line 
  of 
  di- 
  

   vision 
  between 
  this 
  formation 
  and 
  the 
  Hamilton. 
  

   At 
  the 
  point 
  where 
  the 
  division 
  has 
  been 
  made 
  the 
  

   shales 
  suddenly 
  become 
  more 
  arenaceous 
  in 
  charac- 
  

   ter 
  though 
  they 
  still 
  retain 
  their 
  black 
  color 
  except 
  

   that 
  when 
  exposed 
  they 
  weather 
  brown. 
  Marcel- 
  

   lus 
  shales. 
  

   A 
  10 
  A 
  massive 
  gray 
  limestone 
  in 
  which 
  large 
  quantities 
  85=471 
  

   of 
  chert 
  may 
  be 
  found 
  in 
  thin 
  layers. 
  According 
  to 
  

   the 
  statement 
  of 
  Mr 
  H. 
  Ingraham, 
  who 
  drilled 
  a 
  

   well 
  through 
  this 
  formation 
  about 
  a 
  quarter 
  of 
  a 
  

   mile 
  south 
  of 
  Clarksville, 
  the 
  upper 
  nine 
  feet 
  are 
  

   entirely 
  clear 
  of 
  chert, 
  below 
  this 
  are 
  15 
  feet 
  in 
  

   which 
  the 
  chert 
  is 
  very 
  abundant. 
  In 
  the 
  lower 
  

   part 
  of 
  the 
  formation 
  chert 
  was 
  encountered 
  but 
  in 
  

   rather 
  small 
  quantities. 
  

  

  There 
  is 
  an 
  outlier 
  of 
  this 
  formation 
  which 
  forms 
  

   the 
  top 
  of 
  the 
  ridge 
  east 
  of 
  the 
  village, 
  and 
  when 
  

   the 
  Oniskethau 
  creek 
  cut 
  through 
  this 
  ridge 
  the 
  

   outlying 
  area 
  was 
  cut 
  off 
  from 
  the 
  rest 
  of 
  the 
  form- 
  

   ation. 
  This 
  outlier 
  was 
  mentioned 
  by 
  Mr 
  Darton 
  

   who 
  noted 
  the 
  infrequency 
  of 
  such 
  outliers 
  in 
  this 
  

   formation. 
  The 
  measurement 
  of 
  this 
  formation 
  

   was 
  taken 
  at 
  the 
  foot 
  of 
  Bennett 
  rather 
  than 
  Wolf 
  

   hill 
  because 
  the 
  exposure 
  there 
  permitted 
  it 
  to 
  be 
  

   more 
  accurately 
  done. 
  Onondaga 
  limestone. 
  

  

  al3th 
  an. 
  rep't 
  N. 
  Y. 
  state 
  geol. 
  p. 
  242. 
  

  

  