﻿512 
  S'EW 
  YORK 
  STATE 
  MUSEUM 
  

  

  white 
  beds, 
  Hudson 
  shales, 
  Hudson 
  nd 
  ;in<l 
  green 
  states 
  and 
  

  

  Hudson 
  thin 
  quartzite. 
  The 
  Hudson 
  gril 
  (graywacke) 
  is 
  inter 
  

  

  bed< 
  man} 
  places 
  with 
  black 
  Bhales 
  or 
  slates, 
  which 
  in 
  a 
  

  

  .i! 
  onrnber 
  of 
  localities 
  furnished 
  the 
  typical 
  Normans 
  kill 
  

  

  iptolite 
  fauna 
  (identified 
  by 
  \i. 
  \i. 
  Gurley), 
  Many 
  of 
  these 
  lo- 
  

  

  - 
  had 
  been 
  found 
  by 
  CD. 
  Walcott. 
  These 
  graptolite 
  shales 
  

  

  are 
  noi 
  only 
  closely 
  connected 
  with 
  the 
  Hudson 
  grits, 
  as 
  the 
  writer 
  

  

  found 
  them 
  also 
  to 
  be 
  at 
  south 
  Troy 
  (Poesten 
  kill, 
  see 
  j>. 
  539) 
  and 
  

  

  near 
  Easl 
  Qreenbush, 
  but 
  also 
  with 
  the 
  green 
  and 
  red 
  slates; 
  for 
  

  

  "al 
  several 
  points 
  the 
  Hudson 
  grits 
  appear 
  to 
  be 
  replaced 
  along 
  

  

  the 
  by 
  the 
  red 
  and 
  green 
  Ordovician 
  slate" 
  (p. 
  189). 
  

  

  The 
  Trenton 
  limestone 
  (p. 
  100) 
  occurs 
  only 
  sporadically 
  within 
  

   the 
  lower 
  Siluric 
  areas. 
  -In 
  some 
  places 
  it 
  was 
  probably 
  de- 
  

   posited 
  contemporaneously 
  with 
  the 
  Hudson 
  grits 
  and 
  shales, 
  or 
  

   it 
  may 
  underlie 
  portions 
  of 
  them. 
  In 
  others 
  it 
  may 
  represent 
  the 
  

   <ni 
  ire 
  Lower 
  Silurian 
  series 
  and 
  should 
  then 
  be 
  regarded 
  as 
  

  

  enton, 
  Chazy 
  and 
  Calciferous." 
  

  

  This 
  correlation 
  of 
  the 
  Trenton 
  limestone 
  and 
  the 
  Hudson 
  river 
  

   beds 
  is 
  also 
  expressed 
  in 
  the 
  table 
  of 
  formations 
  (p. 
  178), 
  where 
  

   it 
  is 
  said: 
  "Trenton 
  limestone: 
  Limestone, 
  occurring 
  mostly 
  

  

  ^ 
  ; 
  nf 
  the 
  slate 
  belt, 
  replacing 
  probably 
  I 
  (Hudson 
  grits, 
  red 
  and 
  

  

  green 
  slate 
  and 
  graptolite 
  shales), 
  H 
  (Hudson 
  white 
  beds 
  and 
  

  

  Hudson 
  thin 
  quartzite) 
  and 
  (i 
  (Hudson 
  shales), 
  and 
  possibly 
  V 
  

  

  Iciferous) 
  and 
  then 
  representing 
  the 
  Trenton, 
  Ohazy 
  and 
  Cal- 
  

  

  ciferou8. 
  ,J 
  

  

  RESULT 
  <)F 
  POBMEB 
  INVESTIGATIONS 
  

   A 
  brief 
  retrospect 
  of 
  ihr 
  opinions 
  expressed 
  by 
  the 
  various 
  

   authors 
  on 
  the 
  Normans 
  kill 
  fauna 
  will 
  show 
  that 
  there 
  has 
  been 
  

   «' 
  decided 
  trend 
  in 
  these 
  opinions 
  toward 
  :i 
  correlation 
  of 
  the 
  Nor- 
  

   mans 
  kill 
  /.ono 
  wiiii 
  deeper 
  and 
  deeper 
  terranes 
  till 
  now 
  ii 
  

   ciHafc 
  b, 
  bo 
  i- 
  Bay, 
  aboul 
  the 
  lower 
  Trenton. 
  This 
  correlation 
  is 
  

   d 
  entirely 
  on 
  paleontologic 
  evidence 
  and, 
  as 
  r>r 
  Gurley's 
  con- 
  

   tinent 
  clearly 
  shows, 
  is 
  hardly 
  more 
  than 
  tentative. 
  This, 
  

   ,1,,u 
  i 
  ;| 
  >i 
  n. 
  .i 
  be 
  surprising, 
  when 
  ii 
  is 
  borne 
  in 
  mind, 
  that 
  

  

  n11 
  the 
  graptolite 
  beds 
  in 
  New 
  Fork, 
  notably 
  those 
  al 
  Normans 
  

   kill, 
  ili.- 
  Ahh.y 
  (Glenmont), 
  Schodack 
  Landing, 
  Kinderhook 
  and 
  

  

  