﻿NIAGARA 
  FALLS 
  AND 
  VICINITY 
  121 
  

  

  equivalent 
  of 
  the 
  Oriskany 
  sandstone 
  of 
  eastern 
  New 
  York, 
  though 
  

   no 
  fossils 
  have 
  been 
  found 
  in 
  them. 
  With 
  the 
  exception 
  of 
  these 
  

   layers 
  the 
  Lower 
  Devonic 
  strata 
  are 
  wanting 
  in 
  this 
  region. 
  

  

  The 
  Middle 
  Devonic 
  is 
  however 
  well 
  represented 
  in 
  the 
  Niagara 
  

   region 
  by 
  the 
  Onondaga 
  limestone. 
  This 
  rock, 
  which, 
  as 
  has 
  been 
  

   shown, 
  rests 
  in 
  most 
  cases 
  directly 
  on 
  the 
  Manlius 
  Hmestone, 
  con- 
  

   sists 
  of 
  a 
  lower 
  crystalline 
  and 
  highly 
  fossiliferous 
  portion, 
  and 
  an 
  

   upper 
  mass 
  full 
  of 
  layers 
  of 
  hornstone 
  or 
  chert 
  which 
  on 
  weathered 
  

   surfaces 
  stand 
  out 
  in 
  relief. 
  This 
  part 
  of 
  the 
  formation 
  is 
  generally 
  

   known 
  as 
  the 
  Corniferous 
  limestone, 
  in 
  reference 
  to 
  the 
  layers 
  of 
  

   chert 
  which 
  make 
  the 
  rock 
  unfit 
  for 
  other 
  use 
  than 
  rough 
  building. 
  

   Owing 
  to 
  the 
  presence 
  of 
  the 
  hornstone, 
  this 
  rock 
  effectually 
  re- 
  

   sists 
  the 
  attacks 
  of 
  the 
  atmosphere, 
  and 
  hence 
  its 
  line 
  of 
  O'Ut- 
  

   crop 
  is 
  generally 
  marked 
  by 
  a 
  prominent 
  topographic 
  relief 
  feature, 
  

   the 
  second 
  escarpment 
  of 
  western 
  New 
  York 
  i. 
  e. 
  the 
  inface 
  of 
  the 
  

   Onondaga 
  cuesta. 
  

  

  The 
  chert-free 
  lower 
  member 
  of 
  this 
  formation 
  varies 
  greatly 
  in 
  

   thickness 
  even 
  within 
  a 
  limited 
  territory. 
  It 
  is 
  in 
  places 
  extremely 
  

   rich 
  in 
  corals, 
  and 
  outcrops 
  of 
  this 
  rock 
  show 
  all 
  the 
  characteristics 
  

   of 
  an 
  ancient 
  coral 
  reef. 
  

  

  History 
  of 
  the 
  Niag-ara 
  region 
  during 
  Siluric 
  time 
  

  

  We 
  have 
  now 
  gathered 
  data 
  for 
  a 
  brief 
  synopsis 
  of 
  the 
  history 
  of 
  

   this 
  region 
  during 
  Siluric 
  time. 
  Much 
  still 
  remains 
  to 
  be 
  learned, 
  

   but 
  from 
  what 
  is 
  known 
  we 
  can 
  trace 
  at 
  least 
  in 
  outline 
  the 
  sequence 
  

   of 
  geologic 
  events 
  which 
  characterized 
  that 
  ancient 
  era 
  of 
  the 
  earth's 
  

   history 
  in 
  this 
  vicinity. 
  

  

  When 
  the 
  Siluric 
  era 
  opened. 
  New 
  York, 
  with 
  portions 
  of 
  Penn- 
  

   sylvania 
  and 
  southern 
  Ontario, 
  was 
  covered 
  by 
  the 
  shallow 
  Medina 
  

   sea. 
  This 
  sea 
  appears 
  to 
  have 
  been 
  of 
  the 
  nature 
  of 
  a 
  mediter- 
  

   ranean 
  body 
  of 
  water, 
  which 
  later 
  changed 
  to 
  a 
  bay 
  opening 
  toward 
  

   the 
  southwest. 
  This 
  "Bay 
  of 
  New 
  York", 
  as 
  we 
  shall 
  call 
  it, 
  came 
  

   into 
  existence 
  by 
  the 
  orogenic 
  disturbances 
  which 
  marked 
  the 
  transi- 
  

   tion 
  from 
  the 
  Ordovicic 
  to 
  the 
  Siluric 
  era, 
  and 
  as 
  a 
  result 
  of 
  which 
  

   the 
  Taconic 
  mountain 
  range, 
  with 
  the 
  Green 
  mountains 
  and 
  the 
  

   corresponding 
  Canadian 
  ranges, 
  were 
  elevated. 
  This 
  cut 
  of¥ 
  the 
  

  

  