﻿442 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  , 
  If 
  this 
  rock 
  showed 
  this 
  same 
  character 
  at 
  other 
  points 
  it 
  

   would 
  show 
  it 
  to 
  be 
  an 
  important 
  bed, 
  and 
  to 
  determine 
  this 
  

   additional 
  analyses 
  were 
  made 
  by 
  Mr 
  Newland. 
  The 
  first 
  of 
  

   these 
  represents 
  the 
  average 
  of 
  several 
  samples 
  taken 
  "from 
  

   Snow's 
  quarry 
  at 
  Gates 
  near 
  Rochester: 
  , 
  

  

  Silica 
  70 
  

  

  Magnesia 
  20 
  . 
  05 
  

  

  Lime 
  30.50 
  

  

  Alumina 
  .95 
  

  

  Ferric 
  oxid 
  .80 
  

  

  Carbon 
  dioxid 
  45 
  . 
  24 
  

  

  Ignition 
  073 
  

  

  Undet 
  2.687 
  

  

  - 
  ■ 
  • 
  

  

  101.000 
  

  

  The 
  last 
  analysis 
  is 
  of 
  a" 
  sample 
  from 
  the 
  Copeland 
  quarry 
  in 
  

   Rochester, 
  collected 
  by 
  G. 
  van 
  Ingen: 
  

  

  Silica 
  29 
  

  

  Alumina 
  .43 
  

  

  Ferric 
  oxid 
  .46 
  

  

  Loss 
  on 
  ignition 
  .07 
  

  

  Lime 
  carbonate 
  56 
  . 
  01 
  

  

  Magnesia 
  carbonate 
  43 
  .30 
  

  

  100.56 
  

  

  This 
  shows 
  the 
  rock 
  to 
  be 
  an 
  almost 
  pure 
  dolomite. 
  

  

  The 
  Clinton 
  limestone 
  also 
  occurs 
  in 
  Monroe 
  co. 
  and 
  is 
  to 
  

   be 
  seen 
  outcropping 
  at 
  the 
  middle 
  falls 
  at 
  the 
  gorge 
  at 
  the 
  Gene- 
  

   see 
  river 
  at 
  Rochester. 
  

  

  No 
  analyses 
  of 
  it 
  are 
  available 
  but 
  it 
  is 
  not 
  a 
  very 
  important 
  

   formation. 
  

  

  Montgomery 
  county 
  

  

  The 
  Helderberg 
  limestone 
  belt 
  does 
  not 
  come 
  within 
  the 
  limits 
  

   of 
  the 
  county 
  but 
  both 
  the 
  Trenton 
  and 
  Calciferous 
  are 
  present. 
  

  

  Good 
  exposures 
  of 
  the 
  Calciferous 
  occur 
  near 
  the 
  N. 
  Y. 
  C. 
  & 
  

   H. 
  R. 
  R. 
  R. 
  at 
  Amsterdam 
  and 
  St 
  Johnsville, 
  Canajoharie 
  and 
  

   Tribeshill. 
  

  

  