﻿NIAGARA 
  FALLS 
  AND 
  VICINITY 
  QI 
  

  

  beds 
  with 
  the 
  bryozoan 
  weathered 
  out 
  in 
  reUef 
  on 
  their 
  surfaces, 
  

   may 
  be 
  found 
  at 
  the 
  base 
  of 
  the 
  clifif 
  in 
  the 
  cut 
  north 
  of 
  the 
  tunnel. 
  

  

  3 
  In 
  the 
  northern 
  end 
  of 
  the 
  section 
  the 
  sandstones 
  and 
  sandy 
  

   shales 
  have 
  a 
  thickness 
  of 
  about 
  5 
  feet, 
  and 
  are 
  in 
  turn 
  succeeded 
  

   by 
  6 
  feet 
  of 
  shale, 
  weathering 
  readily 
  into 
  a 
  clayey 
  earth, 
  which 
  ac- 
  

   cumulates, 
  as 
  a 
  talus 
  on 
  the 
  underlying 
  sandstone 
  ledges. 
  As 
  

   in 
  the 
  other 
  shale 
  cliffs, 
  so 
  here 
  weathering 
  causes 
  a 
  more 
  rapid 
  

   retreat 
  of 
  the 
  shale 
  than 
  of 
  the 
  overlying 
  sandstone, 
  which 
  therefore 
  

   projects 
  beyond 
  the 
  shale 
  cliff 
  till 
  it 
  breaks 
  down. 
  

  

  These 
  shales 
  are 
  mostly 
  gray, 
  sometimes 
  greenish 
  gray, 
  with 
  oc- 
  

   casional 
  sandstone 
  bands. 
  Toward 
  the 
  top 
  they 
  become 
  intercalated 
  

   .with 
  reddish 
  bands, 
  and 
  finally 
  the 
  prevailing 
  color 
  of 
  the 
  shale 
  be- 
  

   comes 
  red. 
  

  

  4 
  Following 
  these 
  shales 
  is 
  a 
  mass 
  of 
  sandstone 
  from 
  35 
  

   to 
  40 
  feet 
  thick 
  and 
  consisting 
  mostly 
  of 
  beds 
  which 
  vary 
  from 
  

   4 
  to 
  6 
  inches 
  in 
  thickness. 
  The 
  sandstone 
  is 
  compact 
  and 
  solid, 
  

   reddish 
  in 
  color 
  or 
  gray 
  mottled 
  with 
  red. 
  The 
  beds 
  are 
  separated 
  

   by 
  red 
  shaly 
  partings, 
  with 
  occasional 
  beds 
  of 
  red 
  shale 
  2 
  to 
  4 
  feet 
  

   thick. 
  About 
  20 
  feet 
  above 
  the 
  base 
  of 
  this 
  sandstone 
  mass 
  is 
  a 
  

   concretionary 
  layer 
  from 
  i 
  to 
  2 
  feet 
  thick, 
  which 
  appears 
  not 
  unlike 
  

   a 
  bed 
  of 
  large 
  rounded 
  boulders. 
  These 
  concretions 
  vary 
  in 
  size 
  

   up 
  to 
  3 
  or 
  4 
  feet 
  in 
  greatest 
  diameter, 
  and 
  they 
  lie 
  in 
  close 
  juxta- 
  

   position, 
  not 
  infrequently 
  piled 
  on 
  each 
  other, 
  thus 
  still 
  more 
  

   simulating 
  the 
  blocks 
  of 
  a 
  boulder 
  bed. 
  

  

  This 
  sandstone 
  cliff 
  is 
  in 
  general 
  quite 
  perpendicular, 
  and 
  the 
  

   thin 
  and 
  comparatively 
  uniform 
  layers, 
  which 
  are 
  regularly 
  divided 
  

   by 
  vertical 
  joint 
  fissures, 
  produce 
  the 
  appearance 
  of 
  a 
  vertical 
  wall 
  

   of 
  masonry, 
  for 
  which 
  many 
  people, 
  seeing 
  it 
  only 
  from 
  the 
  rapidly 
  

   moving 
  train, 
  have 
  no 
  doubt 
  mistaken 
  it. 
  The 
  regularity 
  

   of 
  these 
  successive 
  beds 
  is 
  at 
  times 
  interrupted 
  by 
  a 
  heavier 
  layer, 
  

   either 
  red 
  or 
  gray 
  and 
  mottled, 
  which 
  may 
  be 
  traced 
  for 
  some 
  dis- 
  

   tance, 
  after 
  which 
  it 
  thins 
  out 
  and 
  disappears. 
  This 
  thinning 
  out 
  

   of 
  the 
  layers 
  in 
  one 
  or 
  another 
  direction 
  is 
  a 
  common 
  and 
  charac- 
  

   teristic 
  feature 
  of 
  these 
  sandstones, 
  and 
  is 
  a 
  direct 
  result 
  of 
  the 
  ir- 
  

   regularities 
  of 
  current 
  action 
  during 
  the 
  deposition 
  of 
  the 
  sands. 
  

   We 
  may 
  trace 
  a 
  sandstone 
  mass 
  for 
  some 
  distance, 
  and 
  then 
  find 
  

  

  