﻿ECONOMIC 
  GEOLOGY 
  196 
  

  

  Triassic 
  formation 
  

  

  This 
  formation, 
  which 
  is 
  known, 
  locally, 
  as 
  the 
  red 
  sandstone, 
  

   is 
  limited 
  in 
  New 
  York 
  to 
  a 
  triangular 
  area 
  in 
  Eockland 
  county, 
  

   between 
  Stony 
  Point 
  on 
  the 
  Hudson 
  and 
  the 
  New 
  Jersey 
  line, 
  

   and 
  to 
  a 
  small 
  outcrop 
  near 
  the 
  north 
  shore 
  of 
  Staten 
  Island, 
  

   which 
  is 
  the 
  southern 
  end 
  of 
  the 
  same 
  belt. 
  

  

  The 
  sandstones 
  are 
  both 
  shaly 
  and 
  silicious, 
  and 
  the 
  varieties 
  

   grade 
  into 
  one 
  another. 
  Conglomerates 
  of 
  variegated 
  shades 
  of 
  

   color 
  also 
  occur, 
  interbedded 
  with 
  the 
  shales 
  and 
  sandstones. 
  

   Formerly 
  these 
  conglomerates 
  were 
  in 
  favor 
  for 
  the 
  construction 
  

   of 
  furnace 
  hearths. 
  They 
  are 
  not 
  now 
  quarried. 
  The 
  prevailing 
  

   color 
  of 
  the 
  sandstone 
  is 
  dark-red 
  to 
  brown, 
  whence 
  the 
  name 
  

   ^ 
  brownstone.' 
  In 
  texture 
  there 
  is 
  a 
  wide 
  variation, 
  from 
  fine 
  

   conglomerates, 
  in 
  which 
  the 
  rounded 
  grains 
  are 
  somewhat 
  loosely 
  

   aggregated, 
  to 
  the 
  fine, 
  shaly 
  rock 
  and 
  the 
  ^ 
  liver 
  rock 
  ' 
  of 
  the 
  

   quarrymen. 
  Oxide 
  of 
  iron 
  and 
  some 
  carbonate 
  of 
  lime 
  are 
  the 
  

   cementing 
  materials 
  in 
  these 
  sandstones. 
  

  

  The 
  well-known 
  Massachusetts 
  Longmeadow 
  sandstone 
  and 
  the 
  

   Connecticut 
  brow^nstone 
  are 
  obtained 
  from 
  quarries 
  in 
  the 
  Con- 
  

   necticut 
  valley 
  region, 
  and 
  of 
  the 
  same 
  geological 
  horizon. 
  The 
  

   Littlefalls, 
  Belleville 
  and 
  Newark 
  freestones 
  are 
  from 
  the 
  same 
  

   formation 
  in 
  its 
  southwest 
  extension 
  into 
  New 
  Jersey. 
  

  

  Quarries 
  were 
  opened 
  in 
  this 
  sandstone 
  more 
  than 
  a 
  century 
  

   ago, 
  and 
  many 
  of 
  the 
  old 
  houses 
  of 
  Rockland 
  county 
  are 
  built 
  of 
  

   it. 
  Prof. 
  Mather 
  reported 
  31 
  quarries 
  on 
  the 
  bank 
  of 
  the 
  

   Hudson 
  near 
  Nyack. 
  The 
  principal 
  market 
  was 
  New 
  York 
  city, 
  

   and 
  the 
  stone 
  was 
  sold 
  for 
  flagging, 
  house 
  trimmings 
  and 
  com- 
  

   mon 
  walls. 
  The 
  Nyack 
  quarries 
  have 
  been 
  abandoned, 
  with 
  one 
  

   or 
  two 
  exceptions, 
  as 
  the 
  ground 
  has 
  become 
  valuable 
  for 
  villa 
  

   sites 
  and 
  town 
  lots. 
  There 
  are 
  small 
  quarries 
  at 
  Suffern, 
  near 
  

   Congers 
  Station, 
  near 
  New 
  City 
  and 
  at 
  the 
  foot 
  of 
  the 
  Torn 
  

   mountain 
  west 
  of 
  Haverstraw. 
  They 
  are 
  worked 
  irregularly 
  and 
  

   for 
  local 
  supplies 
  of 
  stone. 
  The 
  stone 
  is 
  sometimes 
  known 
  as 
  

   * 
  Nyack 
  stone,' 
  also 
  as 
  ^ 
  Haverstraw 
  stone.' 
  

  

  