﻿Report 
  of 
  the 
  State 
  Geologist. 
  209 
  

  

  shaft 
  which 
  has 
  yet 
  been 
  accomplished. 
  In 
  latitude 
  it 
  is 
  a 
  little 
  

   south 
  of 
  the 
  line 
  of 
  the 
  Greigsville 
  and 
  Eetsof 
  salt 
  shafts, 
  and 
  is 
  

   in 
  a 
  line 
  almost 
  due 
  east 
  from 
  Geneseo, 
  and 
  is 
  twenty-seven 
  miles 
  

   due 
  south 
  from 
  Kochester. 
  The 
  elevation 
  however 
  of 
  its 
  position, 
  

   or 
  of 
  the 
  summit 
  of 
  the 
  land 
  on 
  the 
  east, 
  is 
  not 
  so 
  great 
  as 
  the 
  

   general 
  elevation 
  of 
  the 
  higher 
  portions 
  of 
  the 
  country 
  on 
  the 
  

   west, 
  between 
  Conesus 
  lake 
  and 
  the 
  Genesee 
  valley. 
  

  

  The 
  geological 
  relations 
  of 
  the 
  shaft 
  show 
  that 
  it 
  is 
  mainly 
  in 
  

   the 
  rocks 
  of 
  the 
  Hamilton 
  group, 
  to 
  the 
  depth 
  of 
  about 
  800 
  feet,* 
  

   the 
  first 
  excavation 
  being 
  within 
  the 
  limits 
  of 
  the 
  northern 
  exten- 
  

   sion 
  of 
  the 
  lower 
  Portage 
  shales. 
  Therefore, 
  in 
  penetrating 
  to 
  

   the 
  bottom 
  of 
  the 
  salt, 
  the 
  entire 
  thickness 
  of 
  the 
  Genesee 
  and 
  

   Hamilton 
  groups 
  has 
  been 
  passed 
  through 
  ; 
  the 
  Marcellus 
  shale, 
  

   the 
  Corniferous 
  limestone, 
  and 
  the 
  attenuated 
  western 
  extension 
  

   of 
  the 
  Oriskany 
  sandstone 
  ; 
  as 
  well 
  as 
  of 
  the 
  Lower 
  Helderberg 
  

   group 
  and 
  water 
  lime, 
  before 
  coming 
  to 
  the 
  Salt 
  group 
  proper. 
  

  

  The 
  elevation 
  at 
  the 
  opening 
  of 
  the 
  shaft 
  (1,082 
  feet 
  above 
  tide 
  

   water), 
  is 
  higher 
  than 
  the 
  Greigsville 
  and 
  Eetsof 
  shafts, 
  but 
  not 
  

   so 
  high 
  as 
  the 
  mouths 
  of 
  several 
  of 
  the 
  salt 
  wells 
  at 
  Warsaw 
  

   and 
  vicinity 
  in 
  Wyoming 
  county. 
  

  

  The 
  salt 
  group, 
  as 
  developed 
  in 
  central 
  New 
  York, 
  consists 
  of 
  

   three 
  members, 
  the 
  lower 
  two 
  making 
  the 
  greater 
  part 
  of 
  the 
  

   entire 
  thickness 
  of 
  about 
  one 
  thousand 
  feet. 
  The 
  lower 
  member 
  

   is 
  a 
  red 
  shale 
  or 
  marl 
  with 
  little 
  calcareous 
  matter, 
  and 
  was 
  the 
  

   first 
  deposit 
  from 
  this 
  ancient 
  sea 
  after 
  the 
  close 
  of 
  the 
  Magara 
  

   period. 
  Following 
  this 
  come 
  the 
  green 
  shales 
  and 
  marls, 
  weath- 
  

   ering 
  to 
  gray 
  on 
  the 
  outcrop, 
  and 
  often 
  gray 
  before 
  exposure. 
  

   Following 
  this 
  member 
  comes 
  the 
  water 
  lime, 
  which 
  is 
  of 
  gray 
  or 
  

   drab 
  color, 
  and 
  varies 
  greatly 
  in 
  its 
  development 
  and 
  thickness 
  

   along 
  its 
  outcrop. 
  The 
  lower 
  member 
  of 
  the 
  group 
  contains 
  no 
  

   mineral 
  of 
  any 
  economic 
  value, 
  but 
  in 
  its 
  exposure 
  is 
  available 
  for 
  

   brickmaking. 
  The 
  second 
  member 
  contains 
  the 
  gypsum 
  and 
  salt, 
  

   the 
  latter 
  being 
  the 
  later 
  deposit. 
  The 
  third 
  member, 
  the 
  

   water 
  lime, 
  varies 
  considerably 
  in 
  its 
  characters 
  in 
  different 
  

   exposures 
  of 
  its 
  outcrops. 
  It 
  is 
  an 
  important 
  member 
  of 
  the 
  

   series, 
  furnishing 
  nearly 
  all 
  the 
  hydraulic 
  cement 
  in 
  the 
  State 
  of 
  

   New 
  York. 
  

  

  * 
  Eight 
  hundred 
  and 
  sixty-five 
  feet 
  to 
  the 
  Cornif 
  erous 
  limestone, 
  of 
  which 
  seventy 
  feet 
  is 
  to 
  be 
  

   accredited 
  to 
  the 
  drift. 
  

  

  