[kckel.] PENNSYLVANIA. 285 
[been made of the report by Professor Kummel, on the Portland-cement 
industry in New Jersey/' and of an unpublished report by Prof. T. N. 
(Dale, on the geology of the Slatington quadrangle. 
GEOLOGY. 
The "Lehigh district" of the engineer and cement manufacturer 
pus been so greatly extended in recent } 7 ears that the name is now 
hardly applicable. Originally it included merely one small area about 
111 miles square, located along Lehigh River, partly in Lehigh County 
and partly in Northampton County, containing the villages of Egypt, 
jUoplay, Northampton, Whitehall, and Siegfried. The cement plants 
|\vhich were located here at an early date secured control of most 
bf 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 
ICounty, N, J., reaching from near Reading, Pa., at the southwest, to 
la point a few miles north of Stewartsville, N. J., at the northeast. It 
forms, therefore, an oblong area about 25 miles long from southwest 
to northeast and about 4 miles wide. Within this area twenty Port- 
land-cement plants are now in operation, and the Portland cement 
produced in this relatively small district amounts to almost two-thirds 
pi the entire United States output. 
Within the "Lehigh district," as above defined, three geologic 
Iformations occur, all of which must be considered in attempting to 
account for the distribution of the cement materials used there. These 
formations, named in descending order, are (1) Hudson shales, slates, 
and sandstones; (2) Trenton limestone (Lehigh cement rock); (3) Kit- 
tatinny limestone (magnesian). As all these rocks dip, in general, 
northwestward, the Hudson shales occupy the northwestern portion 
of the district, while the Trenton cement rock and magnesian Kit- 
tatinny limestone outcrop in succession farther southeast. 
MAGNESIAN KITTA TINNY LIMESTONE. 
Underneath the cement-rock series lies a very thick formation con- 
sisting of light-gray to light-blue massive-bedded limestone, with 
frequent beds of chert. These Kittatinny limestones are predomi- 
nantly highly magnesian, though occasionally beds of pure nonmag- 
nesian limestone will be found in the series. The magnesian beds are, 
of course, valueless for Portland-cement manufacture, but the pure 
limestone beds furnish part of the limestone used in the Lehigh 
district for addition to the cement rock. An excellent example of 
this is furnished by the quarry near the east bank of Lehigh River, 
a Ann. Rept. New Jersey State Geologist, 1900, pp. 9-101. 
