PENNSYI.VANIAN. 435 



1. Upper Freeport coal; persistent over most of the area of tte formation and workable in many districts. 



2. Upper Freeport limestone member; thin but widely persistent with fossils reported as "fresh-water" in some 

 areas, "marine" in others; accompanied, especially in portions of Westmoreland and Fayette counties, in western 

 Pennsylvania, and in Jefferson and Muskingum counties, Ohio, by the Bolivar clay member. 



3. Butler ("Upper Freeport") sandstone member; highly variable in thickness, or even lacking, being replaced 

 by shales. 



4. Lower Freeport coal; widely persistent and locally very valuable. 



5. Lower Freeport limestone member; usually thin and more or less earthy, with fossils regarded as indicating 

 fresh-water conditions; here and there associated with iron deposits. 



6. Freeport sandstone member ("Lower Freeport sandstone"); white and in places conglomeratic, usually 30 to 

 50 feet or more in thickness; locally a sandy shale. 



7. Upper Kittanning coal (Cement coal); usually present, though variable, and of little importance except in the 

 eastern portion of plateau; rarely recognized in Ohio; carries local cannel near Redbank Creek and in Beaver, Clear- 

 field, and Indiana counties. Pa. 



8. Johnstown limestone member; 1 to 8 feet, magnesian limestone lying 2 to 5 feet beneath the preceding coal, 

 but not found in the western tier of Pennsylvania counties or in Ohio. 



9. Middle Kittanning coal; important as the "Hocking Valley" coal of Ohio, where it is locally roofed by black 

 shale with marine fossils; widespread, with rare cannel, in Pennsylvania, but unimportant except near the Ohio line. 



10. Lower Kittanning coal; very persistent, nearly everywhere; valuable, especially toward the Allegheny Front, 

 also workable in parts of Ohio. 



11. Lower Kittanning clay; valuable, 5 to 15 feet thick west of Allegheny River and passing through Ohio, where 

 it touches the Vanport limestone member; locally, especially at the east, replaced by thick shales or sandstones. 



12. Kittanning sandstone member ("Lower Kittanning sandstone"); local only, chiefly in Butler County, Pa., 

 where it is massive and conglomeratic ; 50 feet or more in thickness. 



13. Buhrstone iron ore; 6 inches to 20 feet thick, highly variable, usually cherty at base, underlain by Vanport 

 limestone member; important in southern Ohio but less regular and persistent east of western counties of Pennsylvania. 



14. Vanport limestone member; familiar as the "Ferriferous limestone;" marine, with rich fauna;™' unknown 

 in the First and Second bituminous basins (east of the Chestnut Ridge anticline) in Pennsylvania; 5 to 20 feet thick 

 in western counties north of Kiskiminitas River; locally present in Ohio, especially toward the south, where it is 

 fairly persistent. 



15. Clarion coal; generally unimportant and less persistent; apparently lacking in considerable areas; a sup- 

 posed split of this coal, the "Scrubgrass" or "Upper Clarion" coal, occurs about 10 to 15 feet higher and less than 

 10 feet below the limestone in portions of western Pennsylvania and over much of Ohio. 



16. Clarion sandstone member; locally massive and thick, especially in southern Ohio, and fairly persistent, 

 though usually insignificant. 



17. Brookville coal; very persistent; recognized in many deep borings beneath the Monongahela formation; 

 usually separated only by its underclay from the Homewood sandstone member of the Pottsville formation; in portions 

 of Ohio a thin marine limestone, known in the Ohio State reports as the Putnam Hill limestone, overlies a coal correlated 

 by Orton *^' and Stevenson '°°° with the Brookville, but it is probable that both limestone and coal are of Mercer 

 age (Pottsville) .'*■ 



Considering the large territory covered, the members of the Allegheny are more regular 

 and persistent than those of either of the contiguous formations. I. C. White/"" confirming 

 the conclusions of the late Edward Orton, State geologist of Ohio, remarks that "all of 

 the main strata in the Allegheny series of western Pennsylvania can be traced bodily 

 across that State [Ohio] from where they enter it in Columbiana County to where they leave it 

 to enter Kentucky from Lawrence County, 250 miles from the Ohio-Pexmsylvania boundary. 

 In this intervening distance some of the coal beds may change in thickness or disappear entirely 

 over areas of considerable size, but they ultimately come into the section again, so that the 

 integrity of the persistent beds of the Allegheny series in Peimsylvania is maintained entirely 

 across the State, and this is true, not only of the coal beds, but also of the limestones, sand- 

 stones, fire clays, and even the iron ores, so that a section in Lawrence. County is practically a 

 duphcate of one in Columbiana." 



The Allegheny, which in northern Pennsylvania reaches a maximum thickness of a little 

 over 300 feet and is in few places less than 250 feet, is thinner in the Broad Top field and thins 

 to less than 250 feet in southwestern Ohio, while in the Kenova quadrangle, in northeastern 

 Kentucky, it decKnes to about 170 feet. Several of its members are attenuated or lacking 

 beneath the higher formations in the axis of the broad bituminous syncline. The local details 

 given with great care in the Ohio and Pennsylvania county reports, cited in the general descrip- 

 tion (p. 431), are surmnarized in the final report of the Second Peimsylvania Geological 



