218 J. J. STEVENSON CARBONIFEROUS OF APPALACHIAN BASIN 



the northerly side being 13 to 19 feet, with 12 to 18 feet of good coal, as 

 measured by Mr Lyman. Near Pottsville the bed is in three splits, with 

 a total of 3 to 16 feet, but. at Tuscarora, 8 miles east, the splits have 

 united into a bed 10 to 17 feet thick. Still farther east two splits appear, 

 20 to 100 feet apart, which unite again eastward, and at the east end of 

 the field the bed is from 9 to 12 feet. 



In the western Middle, east from a line passing rudely north and 

 south through Pottsville, the bed is important, 10 to 18 feet thick, and 

 at the east end single. Westward it is less important and at Mahanoy 

 City is in two splits 20 feet apart. Beyond this it decreases slowly on 

 the southern side of the field, for at 14 miles it is still 4 to 5 feet thick. 

 Northwestwardly from Mahanoy City the decrease continues for a short 

 distance, but the bed recovers and at 10 miles northwest it is 15 feet thick; 

 thence westwardly it loses steadily, becoming 6 feet within 4 miles, 2 to 10 

 feet, but with little good coal, at 7 miles, while at the western end it is a 

 worthless mass of black slate. It remains available farther west in this 

 than in the Southern field, for it is good enough to repay working at 

 Shamokin, whereas it is worthless at 14 miles southeast, in the Southern 

 field. 



The variations of this bed in the eastern Middle are unlike those in 

 the other fields. The bed is important to the northern border in the 

 extreme eastern portion, showing at times 25 feet of coal; but westward, 

 in a north and south strip 7 or 8 miles wide, it is worthless. This is 

 north from the area of chief importance in the Southern field. Beyond 

 this space it increases to its former thickness, and so continues to the 

 western end, this portion being north from the important area northwest 

 from Mahanoy City. The "splits" do not separate widely in the eastern 

 Middle. 



The Seven-foot coal bed of the Southern and western Middle is the 

 Gamma of the Eastern. It is often thick, but, except near Mahanoy 

 City, it is a mass of coal and slate in the former fields; it is sometimes 

 6 feet thick, with good coal, in the eastern part of the eastern Middle. 



The Skidmore coal bed of the Southern, Wharton of the Middle, is 

 persistent in the Southern field, where it is practically worthless except 

 at the extreme east end, though occasionallv workable at a little farther 

 west. It is less irregular in the western Middle, where, however, it is 

 important chiefly in the area northwest from Mahanoy City. Farther 

 west in that field it is usually worthless except near Shamokin. In the 

 eastern Middle it is good in the strip where the Buck Mountain is worth- 

 less, but is better farther west, where the lower bed also attains im- 

 portance. 



