Mar., 1910.] 
Pennsylvanian Limestones. 
129 
63 feet below the Lower Mercer. A 2 foot coal also occurs in the 
Alliance well at 60 feet below this limestone. 
Mr. Thomas Hyland, a well driller of Columbiana, Ohio, 
reports to the writer that at numerous points south of Youngs- 
town and as far as 10 or 15 miles east of the state line he has pen- 
etrated a hard black limestone full of beautiful white shells and 
lying not far above the Block Coal and lower than any other 
limestone known to him. 
All of the above data point unmistakably to another lime- 
stone of considerable extent in the Lower Coal Measures of this 
region. It is shown to extend at least as far west as Alliance 
and in heavier body at this point than anywhere else found. So 
far as is known to the writer the only outcrops of this limestone 
occur in Mahoning County and since the best outcrop occurs at 
Lowellville it may be called the Lowellville Limestone. 
CONCLUSION. 
The object of this study has been to ascertain the number, 
the relation, the position, the continuity, and the character of 
these limestones below the Lower Kittanning coal in the territory 
outlined at the beginning of this paper. The principal facts 
gleaned may be set forth briefly in conclusion. 
1 . There are six limestone horizons below the Lower 
Kittanning coal in Stark and Mahoning Counties. The lowest 
and earliest of these is the Lowellville which was first observed 
by Newberry on “Grindstone Run” at Lowellville. It seems 
to lie just below the horizon of the Quakertown coal, and its 
known outcrops are limited to Mahoning County. 
2. The second limestone is the Lower Mercer and was first 
noted by H. D. Rogers in 1858 in Mercer County, Pennsylvania. 
The two layer character pointed out by I. C. White, as occurring 
in Mercer County, is characteristic of this limestone in Mahoning 
County and occurs at Shew’s Mill below Howenstein in Stark 
County. This limestone has been regarded the most persistent 
of the Lower Coal Measure limestones. Whatever may be said 
of it elsewhere, in these counties it is absent equally as often as 
its companion the Upper Mercer. 
3. Two beds of coal occur quite generally below the Lower 
Mercer limestone. The upper one is usually thin and of little or 
no value. The lower one is of mineable thickness in places, lies 
10 to 22 feet below the limestone, and is known as the Lower 
Mercer coal. At Shew’s Mill it lies 22 feet below; 12 to 20 feet 
below on Little Mill Creek and Mahoning River; 10 to 17 below 
on Infirmary Run; and 13 below on Furnace Run. 
4. The third limestone is the Upper Mercer, first recognized 
by Rogers on the Mahoning River and later by White in Mercer 
County as the Upper Mercer limestone. In Mahoning County 
