﻿828 
  NEW 
  YOEK 
  STATE 
  MUSEUM 
  

  

  Owing 
  to 
  its 
  highly 
  feiTiiginoiis 
  nature, 
  it 
  tends 
  to 
  blister 
  when 
  

   burned 
  to 
  vitrification 
  unless 
  heated 
  very 
  slowly. 
  

  

  Clinton. 
  The 
  Clinton 
  group 
  is 
  shale-bearing 
  in 
  it-s 
  lower 
  mem- 
  

   bers 
  in 
  eastern 
  Wayne 
  co. 
  It 
  is 
  a 
  bright 
  green 
  shale 
  and 
  is 
  about 
  30 
  

   feet 
  thick. 
  At 
  Sodus 
  Point 
  the 
  shale 
  is 
  purplish. 
  It 
  occurs 
  at 
  other 
  

   localities, 
  but 
  is 
  very 
  thin, 
  not 
  more 
  than 
  2 
  to 
  4 
  feet. 
  (Hall. 
  

   Geology 
  of 
  the 
  4:th 
  district 
  of 
  New 
  YorJc, 
  p. 
  59) 
  The 
  second 
  

   green 
  shale 
  of 
  the 
  Clinton 
  gToup 
  is 
  less 
  brilliant 
  in 
  color 
  and 
  every- 
  

   where 
  full 
  of 
  fossils. 
  It 
  is 
  well 
  exposed 
  at 
  Roehester 
  and 
  at 
  AVol- 
  

   cott 
  furnace, 
  in 
  the 
  banks 
  of 
  the 
  creek, 
  where 
  it 
  is 
  more 
  than 
  24 
  

   feet 
  thick. 
  The 
  shale 
  is 
  probably 
  frequently 
  calcareous. 
  

  

  Niagara. 
  Though 
  a 
  prolific 
  shale 
  formation 
  in 
  ]^ew 
  York 
  state, 
  

   the 
  writer 
  has 
  not 
  seen 
  any 
  exposures 
  of 
  it 
  which 
  were 
  not 
  either 
  

   very 
  silicious 
  or 
  calcareous, 
  so 
  that 
  it 
  would 
  probably 
  not 
  work 
  well 
  

   for 
  the 
  manufacture 
  of 
  clay 
  products. 
  When 
  ground 
  and 
  mixed 
  

   with 
  water 
  it 
  possesses 
  no 
  plasticity. 
  

  

  According 
  to 
  Prof. 
  Hall 
  {Geology 
  of 
  the 
  Jfth 
  district 
  of 
  New 
  

   York. 
  p. 
  80), 
  the 
  !N^iagara 
  shale 
  forms 
  a 
  member 
  of 
  great 
  develop- 
  

   ment 
  in 
  the 
  lower 
  part 
  of 
  the 
  Niagara 
  group. 
  It 
  is 
  a 
  dark 
  bluish 
  

   shale 
  which, 
  on 
  exposure, 
  forms 
  a 
  bluish 
  gray, 
  marly 
  clay. 
  It 
  is 
  

   well 
  sho^'^m 
  at 
  Lockport, 
  in 
  the 
  sides 
  of 
  the 
  gorge 
  at 
  Pochester, 
  just 
  

   below 
  the 
  railroad 
  bridge, 
  and 
  at 
  many 
  localities 
  in 
  Wayne 
  and 
  

   Monroe 
  co. 
  The 
  lower 
  layers 
  of 
  the 
  shale 
  are 
  less 
  calcareous 
  

   than 
  the 
  upper 
  ones. 
  

  

  The 
  following 
  is 
  a 
  partial 
  analysis 
  of 
  this 
  shale, 
  the 
  sample 
  

   taken 
  from 
  the 
  gorge 
  at 
  Rochester 
  (16th 
  ann. 
  rep't 
  U. 
  S. 
  geol. 
  surv. 
  

   pt 
  4, 
  p. 
  569). 
  

  

  Silica 
  28.35 
  

  

  Alumina 
  10 
  . 
  47 
  

  

  Perric 
  oxid 
  1.90 
  

  

  Lime 
  21. 
  4Y 
  

  

  Magnesia 
  8 
  . 
  24 
  

  

  Alkalis 
  5.73 
  

  

  76.16 
  

  

  H. 
  T. 
  Vulte, 
  analyst 
  

  

  