Mar., 1910.] Pennsylvanian Limestones. 129 



60 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 Loivellville 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 cjuite 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 



