﻿Report 
  of 
  the 
  State 
  Geologist 
  213 
  

  

  the 
  territory 
  between 
  Seneca 
  lake 
  and 
  the 
  western 
  limits 
  of 
  

   Wyoming 
  county. 
  Within 
  the 
  same 
  territory 
  there 
  are 
  four 
  salt 
  

   shafts 
  completed 
  and 
  others 
  in 
  progress. 
  Still 
  further 
  to 
  the 
  

   east 
  of 
  these, 
  and 
  beginning 
  at 
  different 
  horizons, 
  are 
  several 
  

   productive 
  salt 
  wells 
  which 
  are 
  not 
  noted 
  in 
  this 
  report. 
  The 
  

   geographical 
  position 
  of 
  the 
  wells 
  and 
  shafts 
  of 
  the 
  western 
  dis- 
  

   trict 
  is 
  represented 
  on 
  the 
  diagram. 
  

  

  The 
  work 
  on 
  the 
  Livonia 
  salt 
  shaft 
  has 
  enabled 
  us 
  to 
  obtain 
  a 
  

   most 
  complete 
  and 
  satisfactory 
  collection 
  of 
  material 
  from 
  the 
  

   Genesee 
  slate 
  and 
  thence 
  through 
  the 
  Hamilton 
  group 
  and 
  

   all 
  the 
  inferior 
  strata, 
  ending 
  at 
  the 
  base 
  of 
  the 
  salt 
  group. 
  

   This 
  section 
  will 
  serve 
  to 
  give 
  an 
  accurate 
  record 
  of 
  the 
  

   thickness 
  of 
  each 
  member 
  of 
  the 
  series, 
  with 
  its 
  variations 
  in 
  

   character, 
  and 
  will 
  also 
  serve 
  to 
  correct 
  any 
  imperfect 
  observa- 
  

   tions 
  which 
  have 
  been 
  made 
  upon 
  the 
  exposed 
  outcrops 
  of 
  these 
  

   several 
  formations. 
  

  

  In 
  addition 
  to 
  the 
  record 
  of 
  the 
  strata 
  occurring 
  in 
  the 
  Livonia 
  

   shaft, 
  Mr. 
  Luther 
  has 
  supplemented 
  hi* 
  work 
  by 
  observations 
  

   upon 
  the 
  formations 
  above 
  the 
  Hamilton 
  group 
  in 
  their 
  best 
  

   exposures, 
  and 
  we 
  shall 
  have 
  a 
  more 
  complete 
  illustration 
  of 
  the 
  

   strata 
  composing 
  the 
  Portage 
  group 
  in 
  some 
  of 
  its 
  phases 
  than 
  

   we 
  have 
  before 
  possessed. 
  

  

  In 
  the 
  ordinary 
  course 
  of 
  geological 
  observations, 
  our 
  knowl- 
  

   edge 
  is 
  almost 
  wholly 
  derived 
  from 
  the 
  natural 
  exposures 
  along 
  

   the 
  edges 
  or 
  outcrops 
  of 
  the 
  successive 
  formations, 
  whether 
  in 
  

   the 
  main 
  line 
  of 
  outcrop 
  or 
  in 
  the 
  ravines 
  or 
  channels 
  of 
  streams 
  

   cutting 
  across 
  these 
  outcrops. 
  In 
  the 
  firmer 
  rocks, 
  as 
  limestone 
  

   or 
  sandstone, 
  the 
  exposed 
  layers 
  of 
  these 
  rocks 
  are 
  often 
  but 
  little 
  

   changed 
  by 
  the 
  action 
  of 
  the 
  weather, 
  but 
  in 
  all 
  shaly 
  formations 
  

   decomposition 
  and 
  disintegration 
  have 
  taken 
  place 
  to 
  a 
  greater 
  or 
  

   less 
  degree. 
  Under 
  these 
  circumstances 
  of 
  exposure 
  and 
  disinte- 
  

   gration 
  the 
  contained 
  fossils 
  are 
  usually 
  much 
  weathered 
  and 
  

   decomposed, 
  and 
  while 
  the 
  Corals 
  and 
  Brachiopoda 
  may 
  be 
  fairly 
  

   well 
  preserved, 
  the 
  other 
  classes, 
  as 
  Cephalopoda 
  and 
  Lamelli- 
  

   branchiata, 
  are 
  usually 
  in 
  a 
  very 
  unsatisfactory 
  condition 
  of 
  

   preservation. 
  On 
  this 
  account, 
  especially, 
  the 
  collections 
  of 
  fossils 
  

   from 
  the 
  Livonia 
  salt 
  shaft 
  will 
  be 
  unusually 
  valuable 
  and 
  interest- 
  

   ing 
  for 
  the 
  study 
  of 
  all 
  the 
  forms 
  of 
  ancient 
  life 
  from 
  the 
  shales 
  

   of 
  the 
  Hamilton 
  group 
  and 
  the 
  limestones 
  below. 
  Not 
  only 
  have 
  

  

  