﻿88 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  by 
  whitish 
  or 
  greenish 
  bands, 
  both 
  parallel 
  with 
  and 
  at 
  right 
  angles 
  

   to 
  the 
  stratification 
  plane. 
  In 
  the 
  latter 
  case 
  they 
  are 
  seen 
  to 
  lie 
  on 
  

   both 
  sides 
  of 
  a 
  joint 
  fissure, 
  which 
  indicates 
  that 
  the 
  discoloration 
  of 
  

   the 
  rock, 
  often 
  extending 
  to 
  an 
  inch 
  on 
  either 
  side 
  of 
  the 
  joint, 
  is 
  

   due 
  to 
  percolating 
  air 
  and 
  water, 
  the 
  latter 
  probably 
  carrying 
  or- 
  

   ganic 
  acids 
  in 
  solution. 
  The 
  horizontal 
  bands, 
  often 
  several 
  inches 
  

   in 
  thickness, 
  are 
  probably 
  similarly 
  discolored 
  portions 
  along 
  lines 
  

   of 
  greater 
  permeability. 
  

  

  No 
  fossils 
  have 
  been 
  found 
  in 
  these 
  shales. 
  

  

  Gray 
  quartzose 
  sandstone. 
  The 
  red 
  shales 
  terminate 
  abruptly 
  and 
  

   are 
  succeeded 
  by 
  a 
  stratum 
  of 
  gray 
  quartzose 
  sandstone, 
  which 
  is 
  

   very 
  resistant, 
  and 
  wherever 
  exposed, 
  produces 
  a 
  prominent 
  shelf. 
  

   This 
  rock 
  varies 
  somewhat 
  in 
  different 
  portions 
  of 
  its 
  exposure, 
  but 
  

   it 
  averages 
  perhaps 
  25 
  feet 
  in 
  thickness. 
  This 
  bed 
  is 
  exposed 
  along 
  

   the 
  gorge 
  from 
  its 
  mouth 
  to 
  the 
  whirlpool, 
  where 
  it 
  forms 
  a 
  ledge 
  

   at 
  the 
  water's 
  edge, 
  beyond 
  which 
  it 
  passes 
  below 
  the 
  water 
  level. 
  

   It 
  is 
  well 
  shown 
  at 
  Niagara 
  glen, 
  where 
  a 
  spring 
  of 
  cool 
  water 
  issues 
  

   from 
  beneath 
  it, 
  near 
  the 
  water's 
  edge. 
  In 
  the 
  bank 
  on 
  the 
  opposite 
  

   side, 
  where 
  a 
  fine 
  section 
  of 
  the 
  rocks 
  of 
  the 
  gorge 
  is 
  shown, 
  this 
  

   quartzose 
  bed 
  is 
  seen 
  in 
  its 
  full 
  thickness, 
  lying 
  between 
  the 
  red 
  

   shale 
  below 
  and 
  the 
  shales 
  and 
  sandstones 
  above. 
  The 
  red 
  shale 
  

   at 
  the 
  water's 
  edge 
  has 
  crumbled 
  away, 
  leaving 
  the 
  quartzose 
  bed 
  

   projecting 
  from 
  the 
  wall 
  in 
  some 
  cases 
  to 
  a 
  considerable 
  extent. 
  

  

  The 
  quartzose 
  sandstone 
  usually 
  forms 
  beds 
  of 
  considerable 
  thick- 
  

   ness 
  in 
  this 
  region, 
  though 
  near 
  the 
  top 
  of 
  the 
  stratum 
  a 
  number 
  of 
  

   thin 
  beds 
  generally 
  occur. 
  The 
  best 
  exposure 
  for 
  the 
  examination 
  

   of 
  this 
  rock 
  is 
  in 
  the 
  quarries 
  opened 
  up 
  in 
  the 
  terrace 
  on 
  which 
  

   the 
  Lewiston 
  tower 
  of 
  the 
  suspension 
  bridge 
  stands. 
  In 
  these 
  quar- 
  

   ries 
  the 
  sandstone 
  slabs 
  often 
  show 
  smooth 
  surfaces, 
  which 
  generally 
  

   bear 
  markings 
  similar 
  to 
  those 
  formed 
  by 
  waves 
  on 
  a 
  surface 
  of 
  fine 
  

   sand. 
  These 
  wave 
  marks 
  are 
  found 
  in 
  most 
  of 
  the 
  sandstones 
  of 
  

   the 
  Medina 
  group, 
  but 
  they 
  are 
  nowhere 
  in 
  this 
  region 
  so 
  well 
  de- 
  

   veloped 
  as 
  in 
  the 
  upper 
  thin 
  bedded 
  layers 
  of 
  the 
  quartzose 
  sand- 
  

   stone. 
  No 
  fossils 
  have 
  as 
  yet 
  been 
  found 
  in 
  the 
  gray 
  sandstone 
  on 
  

   the 
  Niagara 
  river, 
  though 
  farther 
  east 
  a 
  similar 
  quartzose 
  rock 
  

   shows 
  'shells 
  of 
  the 
  Medina 
  L 
  i 
  n 
  g 
  u 
  1 
  a 
  on 
  the 
  surfaces 
  of 
  the 
  lay- 
  

   ers, 
  which 
  also 
  show 
  wave 
  marks. 
  

  

  