﻿438 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  The 
  following 
  analysis 
  will 
  illustrate 
  well 
  its 
  siliceous 
  and 
  

   magnesian 
  character: 
  

  

  Silica 
  '. 
  10.50 
  

  

  Alumina 
  3 
  . 
  03 
  

  

  Ferric 
  oxid 
  .77 
  

  

  Lime 
  carbonate 
  47.96 
  

  

  Magnesium 
  carbonate 
  36 
  . 
  89 
  

  

  99.15 
  

  

  The 
  Helderberg 
  limestones 
  extend 
  across 
  the 
  southern 
  edge 
  of 
  

   the 
  county 
  as 
  a 
  belt 
  several 
  miles 
  wide 
  whose 
  northern 
  limit 
  

   passes 
  through 
  the 
  towns 
  of 
  Jordanville, 
  Columbia, 
  Cedarville 
  

   and 
  Cedar 
  Lake. 
  They 
  have 
  been 
  quarried 
  at 
  several 
  places, 
  

   Columbia 
  among 
  them, 
  for 
  lime 
  burning, 
  but 
  their 
  distance 
  from 
  

   the 
  railroad 
  is 
  a 
  serious 
  objection. 
  

  

  The 
  Tentaculite 
  limestone 
  is 
  utilized 
  at 
  Columbia 
  south 
  of 
  

   Littlefalls 
  for 
  the 
  manufacture 
  of 
  lime 
  and 
  has 
  the 
  following 
  

   composition 
  : 
  

  

  Silica 
  4.01 
  

  

  Ferric 
  oxid 
  . 
  . 
  . 
  . 
  53 
  

  

  Alumina 
  .48 
  

  

  Lime 
  51.82 
  

  

  Magnesia 
  1 
  . 
  16 
  

  

  .Carbon 
  dioxid 
  41 
  . 
  90 
  

  

  100.80 
  

  

  Trenton 
  limestone. 
  This 
  group 
  of 
  limestones 
  is 
  of 
  some 
  import- 
  

   ance 
  in 
  Herkimer 
  co., 
  but 
  only 
  the 
  Birdseye 
  and 
  Trenton 
  mem- 
  

   bers 
  are 
  present. 
  

  

  Around 
  Littlefalls 
  the 
  Trenton 
  is 
  not 
  over 
  four 
  feet 
  thick 
  ac- 
  

   cording 
  to 
  Darton, 
  but 
  at 
  Ingham 
  Mills 
  the 
  rock 
  is 
  well 
  ex- 
  

   posed 
  in 
  the 
  lime 
  quarry, 
  where 
  nearly 
  15 
  feet 
  of 
  good 
  stone 
  can 
  

   be 
  seen. 
  The 
  quarry 
  is 
  on 
  the 
  property 
  of 
  Sherman 
  Butler. 
  The 
  

   better 
  stone 
  is 
  bluish, 
  fine 
  grained 
  and 
  massive, 
  but 
  in 
  the 
  upper 
  

   part 
  of 
  the 
  quarry 
  it 
  passes 
  into 
  the 
  Utica 
  slate. 
  

  

  