﻿NIAGARA 
  FALLS 
  AND 
  VICINITY 
  IO7 
  

  

  bedding 
  lines 
  may 
  be 
  observed 
  occasionally, 
  indicating 
  that 
  the 
  

   fragments 
  were 
  subject 
  to 
  wave 
  action. 
  The 
  stratum 
  varies 
  in 
  

   thickness 
  from 
  5 
  to 
  6 
  feet, 
  and 
  is 
  occasionally 
  divided 
  by 
  horizontal 
  

   sutures 
  which 
  show 
  a 
  marked 
  stylolitic 
  structure 
  similar 
  to 
  that 
  

   found 
  in 
  the 
  crystalline 
  upper 
  Clinton 
  limestone. 
  The 
  contact 
  be- 
  

   tween 
  this 
  and 
  the 
  underlying 
  stratum 
  is 
  wavy. 
  This 
  rock 
  has 
  been 
  

   quarried 
  at 
  Lockport 
  under 
  the 
  name 
  of 
  Lockport 
  marble. 
  

  

  Geodiferous 
  limestones. 
  The 
  crinoidal 
  limestone 
  is 
  succeeded 
  by 
  

   strata 
  all 
  of 
  which 
  are 
  more 
  or 
  less 
  geodiferous, 
  though 
  varying 
  con- 
  

   siderably 
  in 
  composition 
  and 
  structure. 
  

  

  4) 
  The 
  rock 
  immediately 
  following 
  on 
  the 
  crinoidal 
  bed 
  

   is 
  a 
  4 
  foot 
  stratum 
  of 
  compact, 
  gray 
  fossiliferous 
  Hmestone, 
  

   the 
  fossils 
  being 
  of 
  a 
  fragmentary 
  character. 
  Stratification 
  struc- 
  

   ture 
  is 
  well 
  marked 
  on 
  the 
  weathered 
  surfaces, 
  specially 
  in 
  

   some 
  of 
  the 
  lower 
  beds 
  of 
  the 
  stratum. 
  Sometimes 
  there 
  is 
  

   only 
  one 
  thick 
  bed, 
  at 
  others 
  the 
  stratum 
  consists 
  of 
  a 
  number 
  of 
  

   thin 
  beds 
  with 
  a 
  heavy 
  one 
  near 
  the 
  center. 
  The 
  thin 
  beds 
  show 
  

   the 
  stratification 
  structure 
  best, 
  having 
  at 
  the 
  same 
  time 
  a 
  strongly 
  

   granular 
  character. 
  As 
  the 
  fossils 
  are 
  fragmentary, 
  and 
  only 
  ac- 
  

   cessible 
  on 
  the 
  weathered 
  surfaces, 
  little 
  is 
  known 
  of 
  the 
  organisms 
  

   that 
  constitute 
  it. 
  Crinoid 
  joints 
  occur, 
  but 
  they 
  are 
  less 
  character- 
  

   istic 
  of 
  this 
  than 
  of 
  the 
  lower 
  stratum. 
  Geodes 
  however 
  are 
  not 
  

   uncommon, 
  the 
  cavities 
  being 
  lined 
  with 
  crystals 
  of 
  pearl 
  spar 
  (dolo- 
  

   mite) 
  or 
  filled 
  with 
  masses 
  of 
  snowy 
  gypsum. 
  

  

  5) 
  The 
  fifth 
  stratum 
  of 
  limestone 
  in 
  this 
  series 
  is 
  a 
  finely 
  crystal- 
  

   line 
  magnesian 
  rock, 
  like 
  the 
  others 
  destitute 
  of 
  fossils 
  except 
  in 
  

   so 
  far 
  as 
  these 
  are 
  represented 
  by 
  geodes. 
  The 
  latter 
  are 
  common 
  

   and 
  filled 
  with 
  alabaster, 
  or 
  sometimes 
  with 
  massive 
  or 
  crystallized 
  

   anhydrite. 
  The 
  latter 
  is 
  distinguished 
  from 
  the 
  crystallized 
  gypsum 
  

   or 
  selenite, 
  which 
  it 
  closely 
  resembles, 
  and 
  which 
  occasionally 
  occurs 
  

   in 
  the 
  same 
  beds, 
  by 
  the 
  cleavage, 
  which 
  is 
  rectangular 
  and 
  nearly 
  

   equally 
  perfect 
  in 
  three 
  directions 
  in 
  anhydrite, 
  while 
  it 
  is 
  perfect 
  

   in 
  one 
  direction 
  only 
  in 
  the 
  selenite. 
  

  

  6) 
  A 
  finely 
  crystalHne, 
  somewhat 
  concretionary 
  dolomitic 
  lime- 
  

   stone, 
  3 
  feet 
  thick, 
  next 
  succeeds, 
  the 
  weathered 
  sectional 
  surfaces 
  of 
  

   which, 
  bufif 
  in 
  color, 
  show 
  the 
  fine 
  stratification 
  structure, 
  which 
  

  

  