ALLEGHENY FORMATION EAST OF ALLEGHENIES 79 



and importance southward. At the north it is variable, usually in several 

 benches or broken by numerous partings and often containing much bony 

 coal. Southward, in the Potomac region, it is mined extensively, yield- 

 ing at times 4 or 5 feet of good coal. The Lower Freeport is unim- 

 portant, yielding less than 2 feet of coal at the north and apparently dis- 

 appearing southwardly, as at Henry there is only bone coal and at Thomas 

 a mere trace. Between the Freeport coal beds, one finds occasionally a 

 representative of the Upper Freeport limestone resting on the Butler 

 sandstone, which is very massive and at times conglomerate. A lime- 

 stone is reported in a borehole at Henry 16 feet thick and at a little way 

 below the Lower Freeport, but no trace of it was observed elsewhere. 



The Upper Kittanning is of very uncertain distribution, but at some 

 localities in the Potomac region it has 3 to 4 feet of good coal. It is 

 absent or insignificant in a great part of the area. The Middle and 

 Lower Kittanning coal beds are separated in extensive areas by a mere 

 parting, so that they are mined as one bed; but at Stoyer, in southern 

 Garrett, this parting is 8 feet and elsewhere it increases to as much as 30 

 feet. The united bed is the Davis coal of the Potomac area and the Six- 

 foot of the Georges Creek area. This bed has suffered much from 

 "squeezes," the coal having been removed for considerable spaces both 

 above and below the middle shale ; but on each side of the disturbance the 

 coal reappears and offers a large area free from the irregularity. It has 

 suffered in this respect far more than any of the succeeding beds. x\t 

 times the shale and bone partings so thicken as to render the bed unim- 

 portant commercially. The interval from Upper Freeport to Lower 

 Kittanning varies from 170 to 210 feet. The Freeport sandstone is gen- 

 erally present, but varies greatly in thickness and structure. An irregular 

 coal bed, known as the "Split-six," 30 to 46 feet below the Lower Kittan- 

 ning, is present in the Georges Creek area. The available information 

 does not justify an attempt to correlate it with any bed known farther 

 west. A limestone appears occasionally below the Lower Kittanning in 

 southern Garrett of Maryland and in Tucker of West Virginia, under- 

 lying iron ore in the latter. Doctor White and Doctor Martin see in this 

 a representative of the Vanport (Ferriferous) limestone. It is non- 

 fossiliferous here, but in the next basin westward a fossiliferous limestone 

 has been found which is supposed to be very near this horizon. 



A massive sandstone, in many respects closely resembling the Home- 

 wood of this region and at times 70 feet thick, is between the Lower Kit- 

 tanning and the next coal bed below. This has been correlated with the 

 Clarion sandstone by the Maryland geologists. Two coal beds are below 

 the sandstone, the upper or Parker and the lower or Bluebaugh, separated 



