PORTLAND-CEMENT  RESOURCES  OF  NEW  YORK. 
By  Edwin  C.  Eckel. 
CEMENT-MAKING  ROCKS. 
The  State  of  New  York  now  ranks  fourth  in  the  production  of 
Portland  cement  in  the  United  States.  The  extensive  series  of  lime- 
stones which  outcrop  within  its  borders  and  its  excellent  local 
markets  for  cement  and  cement  products  will  probably  enable  it 
to  improve  its  rank  as  a  Portland-cement  producer  very  materially 
within  the  next  few  years. 
Of  the  many  different  limestone  formations  which  outcrop  in  New 
York  State,  five  are  of  such  thickness,  areal  extent,  and  chemical 
composition  as  to  be  worth  considering  as  sources  of  Portland-cement 
material.  Many  other  limestones  occur  in  the  State,  but  these  others 
may  be  disregarded  here  as  being  usually  too  thin,  of  improper  chem- 
ical composition,  or  too  badly  located  with  regard  to  transportation 
routes,  markets,  or  sources  of  fuel  supply. 
The  five  available  limestones  noted  above,  in  their  geologic  order, 
are  as  follows : 
Portland-cement  rocks  of  'New  York. 
5.  Marls Quaternary. 
4.  Tully    limestone Devonian. 
3.  Helderberg  and  Onondaga  limestones Silurian  and  Devonian. 
2.  Trenton  limestone Lower  Silurian  (Ordovician). 
1.  Chazy  limestone Lower  Silurian  (Ordovician). 
All  of  these  limestones  except  the  first  (Chazy)  are  at  present' 
utilized  in  Portland-cement  manufacture  in  New  York  State. 
The  character  and  distribution  of  the  five  limestone  groups  above 
noted  will  now  be  described  separately  in  the  order  in  which  they 
are  listed  above. 
CHAZY   LIMESTONE. 
DISTRIBUTION. 
The  Chazy  limestone  is  confined  practically  to  the  Lake  Champlain 
Valley.     It  outcrops  on  the  west  shore  of  Lake  Champlain,  a  few 
miles  south  of  Crown  Point  village,  and  is  also  well  shown  in  Crown 
522 
