ALLEGHENY FORMATION OE "WESTERN PENNSYLVANIA BASINS 103 



5 or 6 miles west from measurements in northern Butler where the Middle 

 Kittanning is 70 to 80 feet above the Yanport limestone and 40 feet below 

 the Freeport sandstone, and about 10 miles west from Murrinsville, in 

 that county, where the Upper Kittanning is 120 feet above the Vanport. 

 The Scrubgrass and Brook ville coal beds are here, the latter at 27 to 55 

 feet below the Yanport, the interval decreasing westwardly. The lime- 

 stone is not persistent, but where present is richly fossiliferous. At one 

 place it is 12 feet thick.* 



Areas of Allegheny become more extensive in Lawrence county, south 

 from Mercer and west from Butler. The section lengthens and the Upper 

 Freeport coal bed is reached at many localities. The Darlington coal bed 

 of this county is the Middle Kittanning. 



On the east side the Middle Kittanning is 70 to 80 feet above the Yan- 

 port (Ferriferous) limestone, the interval depending on that between the 

 Lower Kittanning and the Yanport, which varies from 15 to 25 feet, and 

 that between the coals from 40 to 58 feet, these variations being similar 

 to those in the adjacent part of Butler county. The Upper Kittanning 

 is missing and the Middle is at 140 feet below the Upper Freeport, in the 

 southern part of the county. Westwardly, in the northern and middle 

 parts of the county, the Middle Kittanning is quite regularly 70 to 80 

 feet above the Yanport, but along the southern border the interval varies 

 from 100 to 65 feet, the latter at the west near the Ohio border. The 

 Yanport limestone is not wholly persistent, being wanting in a consider- 

 able area, but it is found in most of the county, 15 to 25 feet thick, 

 always double, gray above, blue below, and everywhere richly fossil- 

 iferous in both divisions. The Scrubgrass and Brookville coals appear 

 in a number of the sections, but they as well as the higher coals are of 

 little importance. 



The interval from Upper Freeport to Lower Kittanning is 208 feet in 

 eastern Butler, 190 to about 200 in eastern Lawrence, but decreases to 

 160 feet near the Ohio state line.f 



Beaver county is south from Lawrence along the Ohio line. North 

 from the Ohio river one occasionally finds the Brookville and Clarion 

 coals 15 to 50 feet apart and very thin, at times distributed through a 

 mass of carbonaceous shale. The Yanport limestone is very thick, 22 feet, 

 in the northeast, but becomes thinner southward and westward until, on 

 the river near the Ohio line, it is but one foot thick, and soon after cross- 

 ing into Ohio it practically disappears. At Homewood station, midway 



*I. C. White: Mercer (Q 2), pp. 22, 32, 77, 79, 88, 132. 



■j-I. C. White : Lawrence (Q 2), pp. 76. 84, 86, 92, 94, 98-99, 111, 115, 121-122, 131-132, 

 134-139, 141, 144, 146-147, 152, 159, 161, 162-166, 169, 171, 179, 187, 196, 199. 



