﻿NIAGARA 
  FALLS 
  AND 
  VICINITY 
  III 
  

  

  indicate 
  a 
  nearness 
  to 
  the 
  reef 
  of 
  growing 
  organisms 
  which 
  supplied 
  

   the 
  material 
  for 
  these 
  beds. 
  Geodes 
  lined 
  with 
  dolomite 
  crystals 
  

   occur 
  in 
  this 
  rock, 
  though 
  not 
  so 
  plentifully 
  as 
  at 
  the 
  quarry 
  in 
  the 
  

   _gorge. 
  Below 
  the 
  crystalline 
  limestone 
  is 
  found 
  the 
  cement 
  rock, 
  

   which 
  is 
  from 
  4 
  to 
  10 
  feet 
  thick 
  and 
  is 
  quarried 
  in 
  a 
  tunnel 
  under 
  

   the 
  limestone 
  quarry. 
  

  

  Owing 
  to 
  the 
  resistant 
  character, 
  the 
  limestone 
  is 
  everywhere 
  ex- 
  

   posed 
  in 
  the 
  gorge, 
  forming 
  cHfifs 
  which 
  are 
  almost 
  invariably 
  per- 
  

   pendicular. 
  Large 
  blocks 
  of 
  this 
  rock 
  cover 
  the 
  talus 
  everywhere, 
  

   one 
  of 
  the 
  largest 
  of 
  these 
  being 
  '' 
  Giant 
  rock 
  " 
  along 
  the 
  gorge 
  

   road. 
  This 
  is 
  a 
  block 
  of 
  the 
  upper 
  geodiferous 
  limestone 
  which 
  has 
  

   fallen 
  from 
  above, 
  and 
  now 
  lies 
  with 
  its 
  stratification 
  planes 
  at 
  an 
  

   angle 
  of 
  about 
  45°. 
  

  

  The 
  limestones 
  are 
  well 
  exposed 
  along 
  the 
  gorge 
  road, 
  south 
  of 
  

   the 
  railroad 
  bridges, 
  but 
  without 
  a 
  special 
  permit 
  no 
  one 
  is 
  allowed 
  

   to 
  walk 
  on 
  this 
  roadbed. 
  The 
  contact 
  between 
  the 
  limestone 
  and 
  

   the 
  shale 
  is 
  here 
  very 
  irregular, 
  indications 
  of 
  erosion 
  of 
  the 
  shale 
  

   prior 
  to 
  the 
  deposition 
  of 
  the 
  limestone 
  occurring. 
  The 
  limestone 
  is 
  

   also 
  somewhat 
  concretionary, 
  rounded 
  masses 
  projecting 
  down 
  into' 
  

   the 
  shales. 
  The 
  succession 
  of 
  strata 
  is 
  here 
  as 
  follows 
  : 
  

  

  1 
  Concretionary, 
  irregularly 
  bedded 
  gypsiferous 
  limestone, 
  often 
  

   earthy 
  and 
  with 
  occasional 
  thin, 
  shaly 
  layers; 
  it 
  splits 
  readily 
  into 
  

   slabs 
  perpendicular 
  to 
  the 
  stratification. 
  Thickness 
  6^8 
  feet. 
  

  

  2 
  Fine 
  grained 
  Hmestone 
  with 
  sandy 
  feel, 
  sometimes 
  massive, 
  

   sometimes 
  in 
  shattered 
  layers 
  with 
  earthy 
  or 
  shaly 
  partings, 
  and 
  

   separated 
  from 
  the 
  underlying 
  rock 
  by 
  an 
  earthy 
  layer. 
  It 
  

   weathers 
  to 
  an 
  ashy 
  or 
  sometimes 
  an 
  ocliery 
  color, 
  and 
  varies 
  some- 
  

   what 
  in 
  thickness. 
  The 
  upper 
  layer 
  is 
  however 
  a 
  solid 
  and 
  fine 
  

   grained 
  limestone. 
  Thickness 
  4-4.5 
  feet. 
  

  

  Strata 
  i 
  and 
  2 
  are 
  the 
  equivalent 
  of 
  the 
  cement 
  beds. 
  

  

  3 
  Crystalhne 
  and 
  crinoidal 
  limestone 
  abruptly 
  succeeding 
  the 
  

   lower 
  bed. 
  It 
  is 
  massive 
  though 
  somewhat 
  thin 
  bedded 
  and 
  con- 
  

   tains 
  geoditic 
  cavities 
  filled 
  with 
  gypsum. 
  This 
  continues 
  uniform 
  

   for 
  a 
  thickness 
  of 
  about 
  19 
  feet. 
  

  

  4 
  Compact 
  limestone; 
  concretionary 
  with 
  cavities 
  containing 
  gyp- 
  

   sum 
  and 
  other 
  minerals, 
  and 
  with 
  sphalerite 
  embedded 
  in 
  the 
  rock. 
  

  

  