320 
CEMENT MATERIALS \NI> INDUSTRY 
ll. -4m I 
From 75 to LOO feet of argillaceous limestones and calcareous -late 
are exposed in a cut on the Chesapeake and Western Railroad soutB 
west of Harrisonburg and just west of the Southern crossing. San 
pies from this cut were analyzed by Charles Catlett, with the resul 
shown in No. 2, below. 
A-bout 1 1 miles north of Harrisonburg the Southern Railroad pass 
through a cut about 20 feet high and £00 to 600 feet in length, expol 
ing comparatively horizontal slaty limestones. Upon analysis th 
was found to have the composition shown in No. -t. 
A i nent malt rials in tlte vicinity of Harrisonburg, ^'a. 
irles Catiett, anal; - 
Linieoxide CaO 54.24 
Magnesia Mg< I 
Oxides RA) 
[nsoluble 
1 
2 
:: 
i 
54. 24 
19.00 
38.1 
.60 
L.42 
2. 36 
L.I 
.60 
3.32 
.70 
1 
2.08 
27.06 
7.00 
25. 1 
1. Pure gray limestone from cut on Chesapeake and Western Railroad just east - - 
Southern Railroad. 
ilcareous slates exposed in eut on Chesapeake and Western Railroad just west of crossing 
Southern Railroad. 
3. Dark, friable limesto] - sed at crossing hesapeake and Western and Southern railrc 
nth of Harrisonburg. 
Icareous slates from cut along Southern Railroad, 1| miles north of Harrisonburg. 
Mount Jackson and Newmarket. Numerous exposures of argl 
laceous limestones may be seen in the foothill- of Short Mountai 
several miles east of Mount .lark-on. and also in the immediate viciniti 
of Newmarket. Practically the same thickness of rock is found hei 
as that shown at Woodstock and vicinity, while the analysis of th< 
ro.k- at both of these places indicates that in chemical composition 
least they are similar to the best of Lehigh rock. 
.1 lysis \f T enton limestone from near Mount Jackson, Y". 
Calcium carbonate CaGO 70. 
Magnesium carbonate MgCO 2. 
Silica SiO 18. 
Oxides K <> 8. 
Water H 2 3. 
11' $t - th of & . Most of the outcrops 
the Trenton limestones along the western edge oi this part of tl 
valley are remote from railroad-, so that in spite of the excellent roc 
shown at a number of places exploitation of these limc-tonc- i- n< 
possible at present. Furthermore, throughout a considerable portn 
of this region the argillaceous lime-tone- arc cut out by overthri 
faulting, the magnesian limestones resting upon the shale- or -til 
higher formation.-. But a single area can he mentioned in which the j 
