526  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1904.         [bull.  260. 
I.  Keenan  Lime  Company,  Smith's  basin,  Washington  County.  Twentieth  Ann.  Rept. 
IT.  S.  Geol.  Survey,  pt.  6,  p.  427. 
•2.  Keenan  Lime  Company,  Smith's  basin,  Washington  County.  Bull.  New  lork  State 
IMus.  No.  44,  p.  826. 
:'..  Keenan  Lime  Company,  Smith's  basin,  Washington  County.  II.  Ries,  analyst.  Ibid., 
p.  827. 
4.  Harris  quarry,  near  'Whitehall,  Washington  County.     Ibid. 
5.  Glens  Falls,  Warren  County.  J.  H.  Appleton,  analyst.  Seventeenth  Ann.  Rept. 
U.  S.  Geol.  Survey,  pt.  3,  p.  801. 
6.  Glens  Falls,  Warren  County.     Mineral  Industry,  vol.  6,  p.  97. 
7.  Glens  Falls,  Warren  County.     Bull.  New  York  State  Mus.  No.  44,  p.  825. 
8.  Hewitt  quarry,  Amsterdam,  Montgomery  County.      Ibid.,  p.  749. 
9.  Hewitt  quarry,  Amsterdam,  Montgomery  County.  J.  M.  Sherrerd,  analyst.  Twenti- 
eth Ann.  Rept.  U.  S.  Geol.  Survey,  pt.  6,  p.  427. 
10.  Hewitt  quarry,  Amsterdam,  Montgomery  County.  .1.  M.  Sherrerd,  analyst.  Ibid., 
pt.  6,  p.  427. 
II.  Hewitt  quarry,  Amsterdam,  Montgomery  County.  J.  M.  Sherrerd,  analyst.  Ibid., 
pt.  6,  p.  427. 
12.  Butler  quarry,  Ingham  Mills,  Herkimer  County.  Bull.  New  York  State  Mus.  No. 
44,  p.  788. 
13.  Butler  quarry,  Ingham  Mills,  Herkimer  County.     Ibid. 
14:  Prospect,  Oneida  County.     J.  D.  Irving,  analyst.      Ibid.,  p.  802. 
15.  Waters  quarry,  Lowville,  Lewis  County.     Ibid.,  p.  792. 
16.  Roberts  quarry,  Collinsville,  Lewis  County.     D.  H.  Newland,  analyst.      Ibid.,  p.  791. 
17.  Christy  quarry,  Leyden,  Lewis  County.     Ibid.,  p.  791. 
18.  Snyder  quarry,  Port  Leyden,  Lewis  County.     D.  H.  Newland,  analyst.     Ibid.,  p.  791. 
HELDERBERG    LIMESTONE. 
DISTRIBUTION. 
Regarded  as  possible  sources  of  Portland-cement  materials,  the 
most  important  series  of  limestone  formations  in  New  York  State  is 
that  included  in  the  upper  and  lower  Helderberg  groups.  These 
two  groups,  each  divisible  into  a  number  of  wTell-marked  formations, 
arc  separated  throughout  the  greater  part  of  their  range  by  a  com- 
paratively thin  bed  of  sandstone — the  Oriskany  sandstone — but  for 
the  purposes  of  this  paper  may  be  considered  as  one  series  of  lime- 
stones. The  Helderberg  limestones,  considered  together,  extend  east- 
ward from  Buffalo,  in  Erie  County,  to  Oriskany  Falls,  Oneida 
County.  Here  the  belt  turns  about  S.  30°  E.,  to  near  South  Bethle- 
hem, Albany  County.  From  this  point  the  outcrops  of  the  limestone 
trend  almost  parallel  to  and  a  little  west  of  Hudson  River,  nearly 
to  Kingston.  The  limestone  belt  then  turns  southeastward,  passing 
along  through  Ellenville  and  Port  Jervis  into  Pennsylvania  and 
New  Jersey. 
The  distribution  of  the  Helderberg  limestones  is  described  at  length 
in  the  following  papers,  in  which  maps  and  sections  showing  local 
details  will  be  found : 
Darton,  N.  H.  Report  on  the  Helderberg  limestones:  Thirteenth  Ann.  Rept. 
New  York  State  Geol.,  pp.  197-228. 
—  Report  on  the  Geology  of  Albany  County:  Thirteenth  Ann.  Rept.  New 
York  State  Geol..  pp.  229-262. 
—  Report  on  the  Geology  of  Ulster  County :  Thirteenth  Ann.  Rept.  New 
York  State  Geol.,  pp.  289-372. 
