108 J. J. STEVENSON CARBONIFEROUS OF APPALACHIAN BASIN 



The Fish Creek sandstone (J. J. Stevenson, 1876) is present at most 

 localities just above the Dunkard coal bed. Sometimes it fills the whole 

 interval to the Nineveh limestone. It differs from most of the Dunkard 

 sandstones, in that it is vs^ell cemented and answers well for building 

 stone. This is a characteristic feature for many miles southward in West 

 Virginia. 



The variations in the interval between the Upper "Washington and 

 Nineveh limestones deserve especial consideration. As has been re- 

 marked, the limiting beds are traceable with the utmost ease, and the 

 connecting lines as well as the measurements are so numerous as to leave 

 no room for doubt respecting the relations in by far the greater part of 

 the area. 



At the southwest corner of Washington county, Pennsylvania, these 

 limestones are 150 feet apart ; 5 or 6 miles east the interval is 180, decreas- 

 ing to about 160 in 3 or 4 miles farther. If the highest limestone in 

 Franklin of Washington, 5 miles northeast from the last, be the Nineveh, 

 as supposed, the interval there is but 150 feet. In the northern town- 

 ships of Greene this interval, 150 feet near the West Virginia line, 

 increases gradually to about 180 at the most easterly measurement, say 

 15 miles away. These measurements are barometric, but they are 

 checked by a well record near Mneveh, 13 miles east from the West Vir- 

 ginia line, where the Nineveh coal bed is 488 feet above the Waynesburg, 

 making the distance from the Nineveh limestone about 450; so that the 

 interval under consideration cannot be more than 150 feet. A high 

 ridge crosses Greene county in a south-southwesterly direction from near 

 Nineveh. Following the east side of this ridge from Nineveh into 

 Center township, one finds a remarkable increase within 5 miles, for the 

 measurement is 



Nineveh limestone. 



Interval 120 



Dunkard coal bed 2 



Interval 35 



Jollytown limestone 7 



Interval 135 



Upper Washington limestone. 



practically 300 feet, and showing the Pursley coal bed, Eogersville and 

 Jollytown limestones, and the Dunkard coal bed, all of which seem to 

 be wanting in the Nineveh region. On the other side of this ridge, 5 or 

 6 miles northwest, the interval is little more than 150 feet, with these 

 beds wanting; but westward, in Jackson township, the Dunkard and 



