CEMENT-ROCK  DEPOSITS  OF  THE  LEHIGH  DISTRICT  OF  PENN- 
SYLVANIA AND  NEW  JERSEY. 
By  Edwin  C.  Eckel. 
The  following  description  of  the  cement-rock  deposits  and  cement 
industry  in  the  Lehigh  district  is  based  largely  upon  field  work  by  the 
writer  during  the  early  summer  of  1903.  Acknowledgments  are  due 
to  the  managers  and  chemists  of  various  cement  plants  in  the  Lehigh 
district,  who  have  aided  the  writer  greatly  in  this  work.  Use  has  also 
been  made  of  the  report  by  Professor  Kummel,  on  the  Portland-cement 
industry  in  New  Jersey,a  and  of  an  unpublished  report  by  Prof.  T.  N. 
Dale,  on  the  geology  of  the  Slatington  quadrangle. 
GEOLOGY  OF  THE  CEMENT  ROCKS. 
The  " Lehigh  district"  of  the  engineer  and  cement  manufacturer 
has  been  so  greatly  extended  in  recent  }^ears  that  the  name  is  now 
hardty  applicable.  Originally  it  included  merely  one  small  area  about 
4=  miles  square,  located  along  Lehigh  River  partly  in  Lehigh  County, 
and  partly  in  Northampton  County,  and  containing  the  villages  of 
Egypt,  Coplay,  Northampton,  Whitehall,  and  Siegfried.  The  cement 
plants  which  were  located  here  at  an  early  date  secured  control  of  most 
of  the  cement-rock  deposits  in  the  vicinity,  and  plants  of  later  estab- 
lishment have  therefore  been  forced  to  locate  farther  and  farther  away 
from  the  original  center  of  the  district.  At  present  the  district  includes 
parts  of  Berks,  Lehigh,  and  Northampton  counties,  Pa.,  and  Warren 
County,  N.  J.,  reaching  from  near  Reading,  Pa.,  at  the  southwest,  to 
a  few  miles  north  of  Stewartsville,  N.  J.,  at  the  northeast.  It  forms, 
therefore,  an  oblong  area  about  25  miles  in  length  from  southwest  to  J 
northeast,  and  about  4  miles  in  width.  Within  this  area  about  twenty 
Portland  cement  plants  are  now  in  operation,  and  the  Portland  cement 
produced  in  this  relatively  small  district  amounts  to  about  two-thirds 
of  the  entire  United  States  output. 
GENERAL    GEOLOGY    OF    THE    DISTRICT. 
Within  the  "  Lehigh  district,"  as  above  defined,  three  geologic 
formations  occur,  all  of  which  must  be  considered  in  attempting  to 
a  Ann.  Rept.  New  Jersey  State  Geologist  for  1900,  pp.  9-101. 
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