﻿t 
  

  

  Report 
  of 
  the 
  State 
  Geologist, 
  235 
  

  

  apparently, 
  directly 
  upon 
  the 
  Hamilton, 
  the 
  contrast 
  in 
  color 
  and 
  

   character 
  of 
  the 
  shales 
  making 
  the 
  line 
  of 
  contact 
  very 
  distinct. 
  

  

  At 
  no 
  exposure 
  on 
  the 
  east 
  side 
  of 
  Canandaigua 
  lake, 
  nor 
  

   from 
  there 
  to 
  the 
  western 
  limit 
  of 
  the 
  salt 
  field, 
  can 
  any 
  lime- 
  

   stone, 
  either 
  compact 
  or 
  shaly, 
  be 
  found 
  between 
  the 
  Hamilton 
  

   and 
  Genesee 
  groups. 
  

  

  Occasionally, 
  however, 
  a 
  thin, 
  non-continuous 
  layer 
  of 
  iron 
  

   pyrites, 
  covered 
  with 
  rust 
  and 
  with 
  the 
  exposed 
  edges 
  crumbling 
  

   into 
  fine 
  particles, 
  may 
  be 
  seen 
  in 
  precisely 
  the 
  place 
  of 
  the 
  Tully 
  

   limestone, 
  and 
  these 
  lenticular 
  patches 
  of 
  pyrites 
  have 
  been 
  

   found 
  to 
  occur 
  at 
  every 
  exposure 
  of 
  this 
  horizon 
  in 
  the 
  salt 
  

   district. 
  

  

  They 
  are 
  not 
  nodular, 
  but 
  rather 
  thin 
  sheets, 
  compact 
  and 
  

   hard, 
  with 
  upper 
  and 
  lower 
  surfaces 
  comparatively 
  smooth. 
  

   They 
  appear 
  to 
  rarely 
  exceed 
  three 
  inches 
  in 
  thickness, 
  and 
  

   fifteen 
  feet 
  in 
  diameter. 
  They 
  do 
  not 
  form 
  a 
  continuous 
  layer, 
  

   but 
  are 
  generally 
  in 
  close 
  proximity 
  with 
  one 
  another. 
  When 
  

   newly 
  broken 
  the 
  edges 
  are 
  bright 
  yellow, 
  but 
  on 
  exposure 
  

   become 
  rusty 
  and 
  easily 
  escape 
  notice 
  in 
  a 
  rock 
  wall. 
  

  

  The 
  material 
  of 
  which 
  the 
  pyrites 
  layer 
  is 
  composed 
  is 
  very 
  

   refractory, 
  boiling 
  acid 
  having 
  very 
  little 
  effect 
  on 
  it, 
  though, 
  in 
  

   a 
  few 
  instances, 
  it 
  has 
  been 
  found 
  in 
  a 
  crumbling 
  condition 
  from 
  

   weathering. 
  

  

  One 
  fragment, 
  10 
  x 
  8 
  x 
  2-J 
  inches, 
  found 
  in 
  the 
  drift 
  in 
  the 
  

   excavation 
  south 
  of 
  the 
  Livonia 
  shaft, 
  was 
  quite 
  soft 
  and 
  easily 
  

   broken. 
  

  

  This 
  horizon 
  is 
  exposed 
  on 
  the 
  east 
  side 
  of 
  Canandaigua 
  lake 
  

   from 
  near 
  Fisher's 
  cabin, 
  south 
  a 
  mile 
  or 
  more, 
  and 
  on 
  the 
  west 
  

   side 
  of 
  the 
  lake 
  from 
  Black 
  point, 
  about 
  the 
  same 
  distance 
  from 
  

   the 
  shore, 
  and 
  north 
  in 
  the 
  ravines. 
  

  

  Near 
  the 
  top 
  of 
  the 
  falls 
  in 
  Yictoria 
  glen 
  the 
  pyrites 
  layer 
  is 
  

   three 
  inches 
  or 
  more 
  thick. 
  It 
  is 
  exposed 
  in 
  the 
  west 
  bank 
  of 
  

   Hemlock 
  outlet, 
  near 
  Richmond 
  Mills, 
  and 
  in 
  u 
  Jaycox 
  run," 
  

   near 
  Geneseo, 
  Livingston 
  county. 
  

  

  At 
  Fall 
  Brook, 
  near 
  Geneseo, 
  it 
  occurs 
  about 
  twenty-eight 
  feet 
  

   from 
  the 
  bottom 
  of 
  the 
  falls, 
  two 
  inches 
  thick 
  ; 
  also 
  in 
  the 
  top 
  of 
  

   the 
  ravine 
  near 
  the 
  village 
  of 
  Moscow, 
  in 
  the 
  bank 
  of 
  the 
  north 
  

   branch 
  of 
  Beard's 
  creek, 
  and 
  in 
  all 
  three 
  of 
  the 
  larger 
  ravines 
  

  

  