DETAILED GEOLOGY OF BURGETTSTOWN QUADRANGLE. 123 
Pittsburg limestone .—The Pittsburg limestone is well developed 
throughout the township. It is in two beds, each a foot or more in 
thickness, one being dark blue and the other dove color. The follow¬ 
ing intervals were determined: 
Distance between top of Pittsburg limestone and base of Pittsburg coal, Jefferson 
Townsh ip, Pennsylvan ia. 
Feet. 
On road from Hamlin Station to Eldersville_ 7 
On road from Hamlin Station to Lee schoolliouse_18 
From the Pittsburg limestone to the Ames limestone the section 
consists of shale and sandstone, with a larger percentage of shale 
than in other sections of the quadrangle. 
Ames limestone .—In the valley of Harmon Creek the Ames lime- 
stone is a bed 24 feet thick, well filled with crinoid stems. Where 
this stream leaves the quadrangle the limestone is 40 feet above the 
stream bed. From this point it can be easily followed up the creek 
to a point due north of Eldersville, where it goes under cover. Owing 
to the steep rise of the rocks to the northwest, no reliable measure¬ 
ments of the interval between the Ames limestone and the Pittsburg 
coal could be obtained. In the adjoining area of the Steubenville 
quadrangle a measurement of 219 feet was obtained for this interval, 
and this was assumed to hold for Jefferson Township. 
Internals .—By combining all the averages of the previous tables 
the following general averages are found for the different marking 
strata above and below the Pittsburg coal in Jefferson Township: 
Distance between 
marking strata and base of Pittsburg coal, Jefferson Township, 
Pennsylvania. 
Feet. 
Ames limestone to Pittsburg coal- 
Pittsburg coal to Sewickley coal- 
Pittsburg coal to Dinsmore limestone- 
Pittsburg coal to Bulger limestone- 
Pittsburg coal to top of Benwood limestone 
Pittsburg coal to Uniontown coal- 
Pittsburg coal to Waynesburg coal- 
Pittsburg coal to Waynesburg “A” coal- 
219 
102 
138 
167 
204 
213 
279 
Subsurface stratigraphy .—Throughout the northern portion of the 
township the Dunkard sand is found about 420 feet below the Pitts¬ 
burg coal. In this same area the Lower Kittanning coal, called the 
Freeport coal, is noted in all the well records at a distance of GOO 
to 640 feet below the Pittsburg coal. In the southern portion of the 
township the real Freeport coal is noted in well records at a distance 
of about 3G0 feet below the Pittsburg coal, and here the Kittanning 
coal appears to be absent, as it is not noted in the records. The top 
of the Salt sand is from 810 to 840 feet below the Pittsburg coal. 
