﻿400 
  Forty- 
  seventh 
  Report 
  on 
  the 
  State 
  Museum, 
  

  

  tion 
  to 
  the 
  Helderberg 
  fauna 
  in 
  the 
  thin-bedded 
  limestones 
  lying 
  

   between 
  the 
  Oriskany 
  and 
  waterlime 
  rocks 
  about 
  Cayuga 
  lake, 
  

   and 
  in 
  this 
  region 
  these 
  members 
  constitute 
  the 
  formation 
  in 
  its 
  

   western 
  extension, 
  apparently 
  finally 
  giving 
  place 
  to 
  the 
  water- 
  

   lime 
  strata. 
  

  

  The 
  Salina 
  formation, 
  which 
  is 
  such 
  a 
  prominent 
  member 
  of 
  

   the 
  series 
  in 
  central 
  and 
  western 
  New 
  York, 
  thins 
  rapidly 
  east- 
  

   ward 
  and 
  is 
  finally 
  represented 
  by 
  an 
  attenuated 
  development 
  of 
  

   its 
  upper 
  members. 
  This 
  representative 
  is 
  the 
  waterlime 
  series 
  

   which 
  is 
  more 
  or 
  less 
  continuous 
  through 
  eastern 
  New 
  York, 
  

   northern 
  New 
  Jersey 
  and 
  Pennsylvania. 
  • 
  In 
  the 
  country 
  of 
  the 
  

   Helderberg 
  mountains 
  it 
  is 
  not 
  always 
  easily 
  recognizable, 
  and 
  

   when 
  present 
  is 
  often 
  not 
  over 
  a 
  yard 
  in 
  thickness. 
  About 
  Ron- 
  

   dout 
  and 
  Rosendale 
  it 
  comprises 
  thick 
  beds 
  of 
  valuable 
  cement 
  

   rock, 
  and 
  at 
  Howe's 
  Cave 
  there 
  is 
  also 
  a 
  cement 
  bed 
  of 
  workable 
  

   thickness. 
  Buff 
  shaly 
  members 
  of 
  the 
  Salina 
  come 
  in 
  under 
  the 
  

   waterlime 
  beds 
  at 
  Sharon 
  Springs, 
  and 
  red 
  shales 
  north 
  of 
  Rich- 
  

   field 
  Springs, 
  and 
  the 
  formation 
  thickens 
  rapidly 
  from 
  here 
  west- 
  

   ward. 
  

  

  The 
  Niagara 
  formation 
  in 
  Onondaga 
  and 
  Madison 
  counties 
  

   thins 
  rapidly 
  to 
  the 
  eastward, 
  and 
  the 
  last 
  exposure, 
  according 
  

   to 
  Yanuxem, 
  is 
  on 
  Steele's 
  creek, 
  south 
  of 
  Mohawk. 
  It 
  comes 
  in 
  

   again 
  over 
  a 
  small 
  area 
  extending 
  about 
  Schoharie 
  and 
  Howe's 
  

   Cave, 
  in 
  which 
  it 
  has 
  a 
  thickness 
  averaging 
  about 
  five 
  feet. 
  I 
  

   saw 
  no 
  trace 
  of 
  its 
  presence 
  in 
  Albany 
  county, 
  but 
  there 
  are 
  

   small 
  outliers 
  near 
  the 
  Catskill 
  and 
  about 
  Rondout. 
  To 
  the 
  south 
  

   oi 
  Rondout 
  it 
  is 
  certainly 
  absent 
  for 
  many 
  miles, 
  but 
  it 
  comes 
  in 
  

   again 
  in 
  New 
  Jersey 
  where 
  Barrett 
  reports 
  a 
  thickness 
  of 
  fifty 
  

   feet. 
  In 
  its 
  eastward 
  extension 
  the 
  Clinton 
  formation 
  overlaps 
  

   the 
  Niagara 
  for 
  some 
  miles, 
  finally 
  thinning 
  out 
  in 
  the 
  southwest- 
  

   ern 
  corner 
  of 
  Madison 
  county 
  near 
  Salt 
  Springville. 
  It 
  comes 
  in 
  

   again 
  with 
  the 
  Niagara 
  limestone 
  about 
  Howe's 
  Cave 
  and 
  Scho- 
  

   harie 
  as 
  a 
  pyritiferous 
  green 
  shale, 
  which 
  attains 
  a 
  thickness 
  of 
  

   about 
  forty 
  feet. 
  A 
  short 
  distance 
  south 
  of 
  Rondout 
  there 
  begins 
  

   a 
  formation 
  comprising 
  a 
  thin-bedded 
  vitreous 
  quartzite 
  above 
  

   and 
  red 
  to 
  gray 
  shales 
  below, 
  which 
  extends 
  southward 
  between 
  

   the 
  Shawangunk 
  grit 
  and 
  Salina 
  formation. 
  South 
  of 
  Rosendale 
  

   the 
  quartzite 
  member 
  finally 
  gives 
  place 
  to 
  gray 
  sandstones 
  with 
  

  

  