﻿ECONOMIC 
  GEOLOGY 
  187 
  

  

  marked 
  by 
  characteristic 
  properties, 
  which 
  serve 
  for 
  their 
  identi- 
  

   fication, 
  aside 
  from 
  the 
  fossil 
  organic 
  remains 
  by 
  which 
  their 
  

   exact 
  position 
  in 
  the 
  geologic 
  series 
  is 
  fixed. 
  This 
  persistence 
  

   in 
  characters 
  is 
  exemplified 
  in 
  the 
  Medina 
  sandstones, 
  in 
  the 
  

   Devonian 
  bluestone, 
  and 
  in 
  those 
  of 
  Triassic 
  age. 
  

  

  Sandstones 
  occur 
  in 
  workable 
  quantity 
  in 
  nearly 
  all 
  the 
  greater 
  

   divisions 
  of 
  the 
  state. 
  

  

  Quarries 
  have 
  not, 
  however, 
  been 
  opened 
  everywhere 
  in 
  the 
  

   sandstone 
  formations, 
  because 
  of 
  the 
  abundant 
  supply 
  of 
  superior 
  

   stone 
  from 
  favorably 
  situated 
  localities. 
  There 
  are, 
  in 
  conse- 
  

   quence, 
  large 
  sandstone 
  areas 
  and 
  districts 
  in 
  which 
  there 
  is 
  an 
  

   absence 
  of 
  local 
  development, 
  or 
  abandoned 
  enterprises 
  mark 
  a 
  

   change 
  in 
  conditions, 
  which 
  has 
  injuriously 
  affected 
  the 
  quarry 
  

   industry. 
  

  

  Following 
  the 
  geologic 
  order 
  of 
  arrangement 
  and 
  beginning 
  

   with 
  the 
  Potsdam 
  sandstone, 
  the 
  several 
  sandstone 
  formations 
  

   are 
  here 
  briefly 
  reviewed. 
  

  

  Potsdam 
  sandstone 
  

  

  This 
  formation 
  is 
  the 
  oldest 
  in 
  which, 
  in 
  this 
  state, 
  sandstone 
  

   is 
  quarried 
  for 
  building 
  purposes.^ 
  

  

  The 
  bottom 
  beds 
  are 
  of 
  fine, 
  silicious 
  conglomerate; 
  above 
  are 
  

   sandstones 
  generally 
  in 
  thin 
  beds. 
  It 
  is 
  gray-white, 
  yellow, 
  

   brown 
  and 
  red 
  in 
  color. 
  In 
  texture 
  it 
  varies 
  from 
  a 
  strong, 
  com- 
  

   pact 
  quartzite 
  rock 
  to 
  a 
  loosely 
  coherent, 
  coarse-granular 
  mass, 
  

   which 
  crumbles 
  at 
  the 
  touch. 
  

  

  Outcrops 
  of 
  limited 
  area 
  occur 
  in 
  the 
  Mohawk 
  valley. 
  In 
  the 
  

   Champlain 
  valley 
  the 
  formation 
  is 
  well 
  developed 
  at 
  Fort 
  Ann, 
  

   Whitehall, 
  Port 
  Henry 
  and 
  Keeseville, 
  and 
  quarries 
  are 
  opened 
  

   •at 
  these 
  localities. 
  The 
  stone 
  is 
  a 
  hard, 
  quartzose 
  rock, 
  and 
  in 
  

   thin 
  beds. 
  North 
  of 
  the 
  Adirondacks 
  the 
  formation 
  stretches 
  

   westward 
  from 
  Lake 
  Champlain 
  to 
  the 
  St 
  Lawrence; 
  and 
  there 
  

   are 
  quarries 
  in 
  the 
  towns 
  of 
  Malone, 
  Bangor 
  and 
  Moira 
  in 
  Frank- 
  

   lin 
  county; 
  in 
  Potsdam 
  and 
  Hammond 
  in 
  St 
  Lawrence 
  county; 
  

  

  a 
  Some 
  of 
  the 
  sandstones 
  east 
  of 
  the 
  Hudson 
  and 
  in 
  the 
  Taghkanlc 
  range 
  may 
  belong 
  

   to 
  the 
  Lower 
  Cambrian. 
  See 
  Amer. 
  Jour, 
  of 
  Bcienoe, 
  series 
  111, 
  vol. 
  35, 
  pp. 
  399-401. 
  

   But 
  there 
  are 
  no 
  quarries 
  opened 
  in 
  these 
  localities. 
  

  

  