﻿232 
  Forty- 
  seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  ments, 
  but 
  the 
  entire 
  thickness 
  of 
  the 
  Genesee 
  division 
  is 
  not 
  far 
  

   from 
  thirty-five 
  feet, 
  the 
  Styliola 
  layer 
  twelve 
  feet 
  from 
  the 
  base 
  

   and 
  about 
  sixty-five 
  feet 
  above 
  the 
  Encrinal 
  limestone, 
  which 
  is 
  

   well 
  exposed 
  at 
  the 
  falls, 
  half 
  a 
  mile 
  below. 
  

  

  Below 
  the 
  Styliola 
  band 
  the 
  shale 
  is 
  darker, 
  and, 
  as 
  the 
  depth 
  

   increases, 
  more 
  bituminous 
  and 
  fissile. 
  A 
  concretionary 
  layer, 
  

   about 
  fifteen 
  feet 
  from 
  the 
  top 
  of 
  the 
  lower 
  shales, 
  is 
  very 
  per- 
  

   sistent, 
  as 
  is 
  one 
  about 
  the 
  same 
  distance 
  from 
  the 
  bottom 
  of 
  the 
  

   group. 
  

  

  The 
  last 
  layer, 
  as 
  exposed 
  between 
  Richmond 
  Mills 
  and 
  Hem- 
  

   lock 
  lake, 
  in 
  a 
  rock 
  cutting 
  made 
  in 
  laying 
  pipes 
  for 
  the 
  Roches- 
  

   ter 
  water 
  works, 
  is 
  a 
  compact, 
  impure 
  limestone 
  six 
  inches 
  thick, 
  

   and 
  contains 
  many 
  specimens 
  of 
  a 
  small 
  coral. 
  Between 
  this 
  

   and 
  the 
  top 
  of 
  the 
  Hamilton 
  the 
  shale 
  is 
  very 
  black 
  and 
  highly 
  

   bituminous. 
  

  

  The 
  total 
  thickness 
  of 
  the 
  Genesee 
  group 
  at 
  Cananclaigua 
  lake 
  

   is 
  about 
  225 
  feet, 
  at 
  the 
  Livonia 
  shaft 
  16 
  1 
  feet, 
  in 
  the 
  Genesee 
  

   valley 
  125 
  to 
  150 
  feet, 
  in 
  the 
  Oatka 
  valley 
  about 
  100 
  feet 
  and 
  in 
  

   the 
  vicinity 
  of 
  Darien 
  not 
  more 
  than 
  40 
  to 
  50 
  feet. 
  

  

  The 
  Tully 
  limestone 
  is 
  an 
  important 
  and 
  easily 
  recognized 
  

   landmark 
  in 
  the 
  geology 
  of 
  Central 
  New 
  York, 
  westward 
  from 
  

   the 
  southwesterly 
  part 
  of 
  Madison 
  county 
  and 
  the 
  north 
  central 
  

   part 
  of 
  Chenango 
  county, 
  where, 
  according 
  to 
  Prof. 
  S. 
  G. 
  

   Williams, 
  the 
  most 
  easterly 
  exposures 
  show 
  a 
  thickness 
  of 
  fifteen 
  

   or 
  sixteen 
  feet. 
  It 
  attains 
  its 
  greatest 
  thickness, 
  twenty-eight 
  to 
  

   thirty 
  feet, 
  in 
  the 
  vicinity 
  of 
  Skaneateles 
  lake, 
  and 
  thins 
  out 
  

   toward 
  the 
  west, 
  being 
  from 
  twelve 
  to 
  eighteen 
  and 
  one-half 
  feet 
  

   thick 
  on 
  Cayuga 
  lake, 
  fourteen 
  feet 
  thick 
  along 
  the 
  east 
  shore 
  of 
  

   Seneca 
  lake 
  from 
  Ovid 
  to 
  Lodi, 
  ten 
  and 
  one-half 
  to 
  sixteen 
  and 
  

   one-half 
  feet 
  thick 
  along 
  the 
  outlet 
  of 
  Keuka 
  lake, 
  and 
  seven 
  feet, 
  

   with 
  possibly 
  something 
  lacking, 
  at 
  Bellona, 
  in 
  the 
  northeast 
  

   corner 
  of 
  Yates 
  county. 
  

  

  The 
  report 
  on 
  the 
  Geological 
  Survey 
  of 
  the 
  Fourth 
  District 
  

   mentions 
  two 
  exposures 
  in 
  Ontario 
  county, 
  one 
  at 
  Bethel 
  (now 
  

   Gorham), 
  and 
  one 
  four 
  miles 
  northwest 
  of 
  that 
  place 
  in 
  the 
  bed 
  

   of 
  a 
  small 
  stream, 
  where 
  it 
  was 
  but 
  three 
  feet 
  thick. 
  

  

  The 
  limestone 
  was 
  formerly 
  exposed 
  in 
  the 
  bed 
  of 
  Flint 
  creek, 
  

   in 
  the 
  village 
  of 
  Gorham, 
  a 
  short 
  distance 
  north 
  of 
  the 
  flouring 
  

   mill, 
  but 
  a 
  dam 
  built 
  some 
  way 
  below 
  the 
  exposure 
  sets 
  the 
  water 
  

  

  