﻿22 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Depth 
  Thickness 
  

  

  Upper 
  Helderberg 
  j 
  

  

  Lower 
  Helderberg 
  j 
  

  

  250' 
  ■ 
  

  

  j 
  j 
  Onondaga 
  

  

  500' 
  About 
  15' 
  rock 
  salt 
  at 
  6l0' 
  , 
  

  

  Salt 
  group 
  

  

  750' 
  ? 
  Top 
  of 
  Niagara 
  limestone 
  

  

  500' 
  Niagara 
  

   10Q0' 
  Clinton 
  (?) 
  

  

  10(/ 
  Probably 
  mostly 
  Medina 
  

   H00 
  / 
  Medina 
  

  

  900' 
  Bottom 
  of 
  well 
  in 
  Medina 
  

  

  2000' 
  

  

  Of 
  the 
  150' 
  assigned 
  to 
  the 
  Helderberg 
  formations 
  it 
  is 
  probable 
  

   that, 
  as 
  in 
  other 
  known 
  sections 
  in 
  western 
  New 
  York, 
  100 
  feet 
  

   should 
  be 
  considered 
  Corniferous 
  and 
  the 
  lower 
  50 
  feet 
  of 
  water- 
  

   lime 
  should 
  be 
  classed 
  as 
  the 
  upper 
  part 
  of 
  the 
  Onondaga 
  group. 
  

   The 
  Clinton, 
  which 
  Prof. 
  Prosser 
  doubtfully 
  assigns 
  to 
  the 
  1000' 
  

   horizon 
  could 
  hardly 
  have 
  been 
  represented 
  among 
  the 
  samples 
  

   from 
  which 
  the 
  record 
  was 
  compiled. 
  In 
  the 
  Corfu 
  well, 
  which 
  

   agrees 
  in 
  its 
  general 
  features 
  with 
  others 
  in 
  western 
  New 
  York, 
  

   the 
  Niagara 
  limestone 
  is 
  reported 
  to 
  be 
  250 
  feet 
  thick 
  with 
  70 
  

   feet 
  of 
  shales 
  below. 
  The 
  Clinton 
  limestone 
  is 
  30 
  feet 
  thick 
  

   with 
  a 
  thin 
  underlying 
  band 
  of 
  olive 
  shales, 
  the 
  latter 
  averaging 
  

   about 
  five 
  feet. 
  As 
  no 
  sample 
  was 
  taken 
  between 
  1000' 
  and 
  1100', 
  

   the 
  Clinton 
  was 
  probably 
  overlooked. 
  

  

  Wells 
  in 
  Genesee 
  county 
  

  

  Le 
  Roy 
  s 
  

  

  Mr. 
  J. 
  C. 
  Tennant 
  has 
  drilled 
  a 
  w 
  T 
  ell 
  on 
  the 
  Monroe 
  farm, 
  one 
  

   mile 
  east 
  of 
  the 
  village 
  of 
  Le 
  Roy, 
  Genesee 
  co. 
  The 
  elevation 
  of 
  

   this 
  well 
  above 
  tide 
  is 
  690 
  feet. 
  The 
  Medina 
  sandstone 
  w 
  r 
  as 
  found 
  

   at 
  1025 
  feet 
  and 
  proved 
  to 
  be 
  75 
  feet 
  thick. 
  A 
  small 
  showing 
  of 
  

   gas 
  w 
  T 
  as 
  found 
  in 
  the 
  upper 
  part 
  of 
  the 
  sandstone, 
  but 
  was 
  not 
  

   enough 
  to 
  be 
  of 
  any 
  use. 
  The 
  well 
  was 
  completed 
  in 
  red 
  shale 
  at 
  

   1200 
  feet. 
  

  

  