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  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  esee 
  and 
  Erie 
  counties. 
  The 
  gypsum 
  is 
  associated 
  with 
  the 
  SaHna 
  

   formation, 
  which 
  carries 
  the 
  rock 
  salt 
  beds, 
  and 
  is 
  quarried 
  or 
  

   mined 
  along 
  the 
  outcrop 
  from 
  Madison 
  county 
  westward. 
  The 
  

   Salina 
  formation 
  can 
  be 
  traced 
  to 
  the 
  east 
  into 
  Albany 
  county 
  but 
  

   with 
  such 
  diminishing 
  thickness 
  as 
  to 
  preclude 
  the 
  occurrence 
  of 
  

   workable 
  gypsum 
  deposits 
  in 
  that 
  section. 
  

  

  Most 
  of 
  the 
  workings 
  are 
  situated 
  near 
  the 
  southern 
  edge 
  of 
  

   the 
  belt 
  occupied 
  by 
  the 
  Salina 
  beds. 
  The 
  gypsum 
  occurs 
  below 
  

   the 
  Bertie 
  waterlime, 
  which 
  marks 
  the 
  top 
  of 
  the 
  formation, 
  and 
  

   above 
  the 
  salt 
  horizon. 
  Its 
  beds 
  are 
  regularly 
  disposed 
  with 
  respect 
  

   to 
  the 
  inclosing 
  rocks, 
  dipping 
  with 
  them 
  at 
  a 
  very 
  low 
  angle 
  to 
  

   the 
  south. 
  They 
  afford 
  a 
  practically 
  inexhaustible 
  supply. 
  Their 
  

   greatest 
  thickness 
  along 
  the 
  outcrop 
  is 
  in 
  Onondaga 
  county 
  where 
  

   as 
  much 
  as 
  60 
  feet 
  have 
  been 
  found, 
  divided 
  into 
  several 
  layers. 
  

   In 
  the 
  western 
  part 
  of 
  the 
  State 
  the 
  beds 
  range 
  from 
  4 
  to 
  8 
  feet 
  

   thick. 
  Many 
  of 
  the 
  borings 
  for 
  salt 
  have 
  encountered 
  gypsum, 
  

   showing 
  its 
  continuation 
  for 
  long 
  distances 
  to 
  the 
  south 
  along 
  the 
  

   dip 
  of 
  the 
  strata. 
  

  

  The 
  present 
  extensive 
  utilization 
  of 
  gypsum 
  in 
  New 
  York 
  has 
  

   been 
  due 
  to 
  the 
  establishment 
  of 
  plants 
  for 
  the 
  manufacture 
  of 
  

   plaster 
  of 
  paris, 
  stucco, 
  wall 
  plasters, 
  etc., 
  a 
  branch 
  of 
  the 
  industry 
  

   that 
  has 
  grown 
  to 
  large 
  proportions 
  in 
  the 
  last 
  decade. 
  Formerly 
  

   the 
  principal 
  outlet 
  for 
  the 
  mineral 
  was 
  in 
  agriculture, 
  which 
  still 
  

   affords 
  a 
  small 
  market 
  for 
  the 
  ground 
  product. 
  Another 
  use 
  

   that 
  has 
  become 
  quite 
  important 
  is 
  in 
  the 
  portland 
  cement 
  trade; 
  

   a 
  considerable 
  proportion 
  of 
  the 
  gypsum 
  listed 
  in 
  the 
  accompany- 
  

   ing 
  table 
  as 
  sold 
  in 
  crude 
  state 
  is 
  shipped 
  to 
  points 
  in 
  Pennsyl- 
  

   vania 
  and 
  elsewhere 
  for 
  admixture 
  with 
  portland 
  cement. 
  

  

  The 
  gypsum 
  rock 
  as 
  found 
  in 
  New 
  York 
  has 
  a 
  gray 
  or 
  drab 
  

   color. 
  It 
  contains 
  a 
  varying 
  amount 
  of 
  impurities 
  in 
  the 
  form 
  

   of 
  lime 
  and 
  magnesia 
  carbonates, 
  clay 
  and 
  silica 
  or 
  quartz, 
  be- 
  

   sides 
  a 
  small 
  proportion 
  of 
  organic 
  matter 
  which 
  is 
  the 
  principal 
  

   coloring 
  agent. 
  In 
  calcination 
  the 
  organic 
  substances 
  are 
  broken 
  

   up 
  or 
  driven 
  off. 
  The 
  impurities 
  on 
  the 
  average 
  amount 
  to 
  from 
  

   5 
  to 
  15 
  per 
  cent 
  of 
  the 
  total. 
  

  

  Manufacture. 
  Most 
  of 
  the 
  gypsum 
  that 
  is 
  mined 
  or 
  quarried 
  

   in 
  the 
  State 
  undergoes 
  some 
  kind 
  of 
  preparation 
  before 
  shipment. 
  

   In 
  the 
  case 
  of 
  the 
  material 
  sold 
  to 
  portland 
  cement 
  manufactur- 
  

   ers, 
  however, 
  a 
  portion 
  is 
  shipped 
  in 
  lump 
  form 
  tO' 
  be 
  later 
  crushed 
  

   at 
  the 
  cement 
  works 
  and 
  mixed 
  with 
  the 
  clinker 
  before 
  grinding. 
  

   A 
  part 
  of 
  the 
  gypsum, 
  also, 
  is 
  crushed 
  at 
  the 
  mines 
  and 
  shipped 
  

   in 
  bags. 
  A 
  very 
  small 
  quantity 
  is 
  sold 
  in 
  calcined 
  condition 
  to 
  

  

  