﻿86 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Ulrich 
  is 
  inclined 
  to 
  unite 
  it 
  with 
  the 
  Seven 
  foot 
  tier 
  or 
  Watertown 
  

   limestone. 
  We 
  adopt 
  here 
  this 
  view, 
  leaving 
  the 
  final 
  decision 
  as 
  to 
  

   the 
  exact 
  boundaries 
  to 
  a 
  future 
  close 
  study 
  of 
  the 
  faunas 
  involved, 
  

   but 
  consider 
  the 
  difficulty 
  of 
  an 
  easy 
  recognition 
  of 
  this 
  boundary 
  

   — 
  located 
  within 
  a 
  lithologic 
  unit 
  — 
  in 
  the 
  field 
  as 
  another 
  practical 
  

   reason 
  for 
  mapping 
  and 
  discussing 
  here 
  the 
  Leray 
  and 
  Watertown 
  

   limestones 
  together. 
  

  

  Finally, 
  it 
  was 
  found 
  in 
  studying 
  last 
  summer, 
  in 
  company 
  with 
  

   Dr 
  Ami, 
  Professor 
  Gushing 
  and 
  Dr 
  Ulrich, 
  the 
  section 
  at 
  Klock's 
  

   quarry 
  at 
  Watertown 
  [see 
  below 
  p. 
  90], 
  that 
  there 
  is 
  properly 
  

   referred 
  to 
  the 
  Watertown 
  also 
  a 
  bed 
  iy^-2 
  feet 
  thick, 
  of 
  black 
  

   limestone, 
  that 
  still 
  overlies 
  the 
  Seven 
  foot 
  tier. 
  

  

  With 
  these 
  upward 
  and 
  downward 
  extensions 
  of 
  the 
  formation, 
  

   the 
  limestone 
  will 
  be 
  about 
  15 
  feet 
  thick 
  in 
  its 
  type 
  region 
  

   while 
  the 
  Leray 
  limestone 
  is 
  about 
  13 
  feet 
  thick, 
  consisting 
  of 
  dark 
  

   gray 
  to 
  black, 
  heavily 
  bedded, 
  dove 
  limestone, 
  with 
  layers 
  of 
  black 
  

   chert 
  nodules. 
  The 
  nodules 
  are 
  more 
  or 
  less 
  scattered 
  through 
  the 
  

   chert 
  beds, 
  forming 
  here 
  and 
  there 
  strings 
  in 
  the 
  section 
  and 
  a 
  dis- 
  

   tinct 
  horizon 
  over 
  the 
  whole 
  mapped 
  area 
  near 
  the 
  base 
  of 
  the 
  beds. 
  

   Since 
  large 
  rock 
  exposures 
  of 
  the 
  surface 
  of 
  the 
  Leray 
  limestone 
  are 
  

   frequent 
  in 
  the 
  region, 
  one 
  has 
  often 
  opportunity 
  to 
  observe 
  large 
  

   quantities 
  of 
  these 
  cherts, 
  half 
  weathered 
  out, 
  on 
  the 
  rocks, 
  pre- 
  

   senting 
  a 
  flat, 
  cakelike 
  form. 
  Some 
  of 
  the 
  chert 
  beds 
  present, 
  when 
  

   weathered, 
  a 
  peculiarly 
  fucoidal 
  surface 
  through 
  intricate 
  intermix- 
  

   ing 
  of 
  the 
  limestone 
  with 
  earthy 
  films, 
  and 
  others 
  are 
  distinctly 
  

   cross-striated. 
  

  

  The 
  contrast 
  between 
  the 
  massive 
  chert 
  beds 
  and 
  the 
  thinner 
  

   bedded 
  underlying 
  Lowville 
  strata 
  is 
  well 
  shown 
  in 
  plate 
  20. 
  In 
  

   natural 
  exposures 
  or 
  where 
  the 
  quarry 
  face 
  is 
  weathered, 
  the 
  Water- 
  

   town 
  and 
  Leray 
  formations 
  are 
  readily 
  distinguished 
  from 
  the 
  

   lower 
  Lowville 
  beds 
  by 
  their 
  breaking 
  up 
  into 
  small 
  cubic 
  blocks 
  

   the 
  size 
  of 
  a 
  fist. 
  The 
  beginning 
  of 
  this 
  breaking 
  up, 
  which 
  is 
  ap- 
  

   parently 
  due 
  to 
  a 
  reticulate 
  system 
  of 
  mud 
  seams, 
  is 
  seen 
  in 
  plate 
  

   20 
  and 
  farther 
  progressed 
  in 
  plate 
  21. 
  Here 
  the 
  rock 
  is 
  so 
  

   weathered 
  that 
  it 
  can 
  be 
  brought 
  down 
  with 
  the 
  pick 
  and 
  is 
  of 
  con- 
  

   venient 
  size 
  for 
  road 
  metal. 
  It 
  is 
  also 
  well 
  shown 
  on 
  plate 
  19, 
  

   where 
  the 
  hat 
  lies 
  just 
  above 
  the 
  boundary 
  line. 
  This 
  picture 
  ex- 
  

   hibits 
  especially 
  well 
  the 
  contrast 
  between 
  the 
  evenly 
  and 
  thinner 
  

   bedded 
  typical 
  Lowville 
  limestone 
  and 
  the 
  thick 
  bedded 
  blocky 
  

   weathering 
  Leray 
  and 
  Watertown 
  beds. 
  

  

  In 
  plate 
  22 
  will 
  be 
  found 
  an 
  excellent 
  illustration 
  of 
  the 
  uncon- 
  

   formity 
  between 
  the 
  Lowville 
  and 
  Leray 
  limestones. 
  The 
  lower 
  of 
  

  

  